Patent Publication Number: US-2018039399-A1

Title: Interactive user interface for dynamically updating data and data analysis and query processing

Description:
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS 
     Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57. 
     This application is a continuation-in-part of U.S. patent application Ser. No. 15/092964, filed on Apr. 7, 2016, which is a continuation of U.S. patent application Ser. No. 14/858647, filed on Sep. 18, 2015, which claims priority from U.S. Provisional Patent Application No. 62/097327, filed on Dec. 29, 2014. This application also claims benefit of U.S. Provisional Patent Application Ser. No. 62/436906 filed Dec. 20, 2016. Each of the above identified applications is hereby incorporated by reference herein in its entirety and for all purposes. 
    
    
     BACKGROUND 
     The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section. 
     Exploration, mining, and analysis of high-volume data sources and data warehouses can be a time and resource intensive process, both for the user and for the underlying computing systems which provide data analysis features. Large volumes of data contribute to high consumption of computer memory, and processing of such large volumes of data can require extremely powerful computer processors and processing time. Users such as data analysts often face a seemingly insurmountable task of attempting to locate discrete pieces of information from data sources which can include or primarily consist of innocuous or noisy data which provides little probative value. Often, many iterations to explore such data are required, with each iteration having an associated cost in time and resources. 
     SUMMARY 
     One embodiment includes a computer-implemented method comprising: receiving, via a user interface, a request to update a first data node, wherein a first data analysis graph comprises the first data node and one or more additional nodes; identifying an active path from the first data analysis graph; generating duplicate one or more additional nodes from the one or more additional nodes and the active path; generating an updated first data node; generating a second data analysis graph comprising the updated first data node and the duplicate one or more additional nodes; and causing presentation of the second data analysis graph in the user interface. 
     In some embodiments, the computer-implemented method of the preceding paragraph can include a combination or sub-combination of features. The one or more additional nodes can correspond to a user interface visualization and can comprise at least one of: a summary node, a table node, a histogram node, a distribution node, a time series node, a grid node, a heatmap node, a pivot table node, a filter node, a column editor node, an enrich node, a link node, a set math node, or an export node. The computer-implemented method can further comprise identifying, in the first data analysis graph, a parent node of the first data node; and generating a link between the parent node and the updated first data node. The one or more additional nodes can comprise at least two linked nodes according to a first order, the computer-implemented method can further comprise: generating a first link between the updated first data node and the duplicate one or more additional nodes; and generating, according to the first order, a second link between the duplicate one or more additional nodes comprising at least two nodes. Identifying the active path can comprise: accessing historical user interaction data associated with the first data analysis graph; identifying, from the historical user interaction data, a current node from the first data analysis graph; and identifying, as the active path, one or more nodes from the first data analysis graph based at least in part on a dependency of the current node. 
     Another embodiment includes a non-transitory computer storage medium storing computer executable instructions that when executed by a computer hardware processor perform operations comprising: retrieving a first data analysis graph comprising a plurality of nodes; identifying an active path from the first data analysis graph; generating duplicate one or more additional nodes from the plurality of nodes and the active path; identifying, from the duplicate one or more additional nodes and the plurality of nodes, an insertion point between a first data node and a second data node; generating a third data node; generating a second data analysis graph comprising the first data node, the third data node, and the second data node; and causing presentation of the second data analysis graph in a user interface. 
     In some embodiments, the non-transitory computer storage medium of the preceding paragraph can include a combination or sub-combination of features. The operations can further comprise: receiving a node insertion request comprising data corresponding to the insertion point; generating a first link between the first data node and the third data node as indicated by the insertion point; and generating a second link between the third data node and the second data node as indicated by the insertion point. The plurality of nodes can comprise the first node and the duplicate one or additional nodes can comprise the second node. Identifying the active path can comprise: accessing historical user interaction data associated with the first data analysis graph; identifying, from the historical user interaction data, a current node from the first data analysis graph; and identifying, as the active path, one or more nodes from the first data analysis graph based at least in part on a dependency of the current node. The operations can further comprise: identifying a non-transformation node from the active path; identifying, from the active path, subset of nodes that excludes the non-transformation node; identifying an abridged data analysis graph as the subset of nodes; and causing presentation of the abridged data analysis graph in a user interface. Identifying the non-transformation node from the active path can further comprises: determining a node type from a node in the active path; determining that the node type corresponds to a non-transformation node type. Presentation of the second data analysis graph can comprise a workflow visualization. 
     Another embodiment includes a computer system comprising: one or more computer processors configured to execute software code to: retrieve a first data analysis graph comprising a first data node and one or more additional nodes; identify an active path from the first data analysis graph; generate duplicate one or more additional nodes from the one or more additional nodes and the active path; generate an updated first data node; generate a second data analysis graph comprising the updated first data node and the duplicate one or more additional nodes; and cause presentation of the second data analysis graph in a user interface. 
     In some embodiments, the computer system of the preceding paragraph can include a combination or sub-combination of features. The one or more computer processors can be further configured to execute the software code to: receive a request to update the first data node; identify, in the first data analysis graph, a parent node of the first data node; and generate a link between the parent node and the update first data node. The one or more additional nodes can comprise at least two linked nodes according to a first order, and the one or more computer processors can be further configured to execute the software code to: generate a first link between the updated first data node and the duplicate one or more additional nodes; and generate, according to the first order, a second link between the duplicate one or more additional nodes comprising at least two nodes. Identifying the active path can comprise: accessing historical user interaction data associated with the first data analysis graph; identifying, from the historical user interaction data, a current node from the first data analysis graph; and identifying, as the active path, one or more nodes from the first data analysis graph based at least in part on a dependency of the current node. The one or more computer processors can be further configured to execute the software code to: identify a non-transformation node from the active path; identify, from the active path, subset of nodes that excludes the non-transformation node; identify an abridged data analysis graph as the subset of nodes; and cause presentation of the abridged data analysis graph in a user interface. Identifying the non-transformation node from the active path can further comprise: determining a node type from a node in the active path; and determining that the node type corresponds to a non-transformation node type. The one or more computer processors can be further configured to execute the software code to: join a first data set and a second data set to determine a third data set; and store the third data set as a node in the second data analysis graph. The one or more computer processors can be further configured to execute the software code to: access a data set from a node in the second data analysis graph; access report configuration data associated with the node; and generate, in the user interface, a report comprising data from the data set based at least in part on the report configuration data. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A-1M  illustrate an example data analysis workflow performed using several interactive data analysis user interfaces, as generated using one embodiment of the data analysis system of  FIG. 6 . 
         FIGS. 2A-2B  illustrate example data analysis path tree view user interfaces, as generated using one embodiment of the data analysis system of  FIG. 6 . 
         FIG. 3  is a flowchart illustrating one embodiment of an example process for processing data set queries using an interactive data analysis user interface, as used in one embodiment of the data analysis system of  FIG. 6 . 
         FIG. 4  is a flowchart illustrating one embodiment of an example process for generating an interactive breadcrumb and/or an interactive tree view representing a data analysis path for display in a data analysis user interface, as used in one embodiment of the data analysis system of  FIG. 6 . 
         FIG. 5  is a flowchart illustrating one embodiment of an example process for navigating a data analysis path using an interactive breadcrumb and/or an interactive tree view representing the data analysis path in data analysis user interface, as used in one embodiment of the data analysis system of  FIG. 6 . 
         FIG. 6  is a block diagram of an implementation of an illustrative data analysis system. 
         FIG. 7  illustrates another example workflow user interface of the data analysis system, according to some embodiments of the present disclosure. 
         FIGS. 8 and 9  illustrate an example user interface of the data analysis system that presents an abridged data analysis graph, according to some embodiments of the present disclosure. 
         FIG. 10  illustrates an example user interface of the data analysis system that presents a workspace, according to some embodiments of the present disclosure. 
         FIG. 11  illustrates an example user interface of the data analysis system that enables data editing, according to some embodiments of the present disclosure. 
         FIG. 12  illustrates an example report user interface of the data analysis system, according to some embodiments of the present disclosure. 
         FIG. 13  illustrates an example enrichment user interface of the data analysis system, according to some embodiments of the present disclosure. 
         FIG. 14  illustrates an example chart user interface of the data analysis system, according to some embodiments of the present disclosure. 
         FIGS. 15A-15E  illustrate example representations of data analysis graphs, according to some embodiments of the present disclosure. 
         FIG. 16  illustrates flowcharts that correspond to example workflow processes, according to some embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Overview 
     Data analysts face a daunting challenge when tasked with exploring a large volume of data to identify discrete pieces of information and intelligence—a veritable needle-in-a-haystack problem. In some cases a data analyst may have a lead on something she wishes to investigate. For example, knowing that a particular bad actor was involved in an incident may be a starting point from which the data analyst can begin to investigate other individuals who may have been involved. However, in many cases the data analyst has little information or, at best, only some contextual information on which to base an investigation. For example, the data analyst might know that a website was hacked at a certain time but have little else to go on to identify the individuals involved. However, data analysts might need to explore multiple analysis paths, many of which lead to “dead ends” or results that do not answer the search premise, by sorting and filtering through a massive volume of (for example) Internet proxy traffic data, cyber security data, telephone data, and/or any other type of data. The data analyst&#39;s path through the data is often multi-directional, in that the analyst may approach a problem from the top-down, bottom-up, and/or in either direction over the course of a given data analysis path and investigation. For example, the data analyst may begin with a large set of data, submit one or more queries which may lead to smaller sets of data results or filtered data results, and then merge or join smaller sets of data results to formulate larger sets of data, exclude subsets of data, and so on in as many iterations as the data analysts desires or finds useful. 
     The systems and methods described herein provide highly dynamic and interactive data analysis user interfaces which enable the data analyst to quickly and efficiently explore large volume data sources. In particular, a data analysis system, such as described herein, may provide features to enable the data analyst to investigate large volumes of data over many different paths of analysis while maintaining detailed and retraceable steps taken by the data analyst over the course of an investigation, as captured via the data analyst&#39;s queries and user interaction with the user interfaces provided by the data analysis system. For example, one data analysis path may begin with a high volume data set, such as Internet proxy data, which may include trillions of rows of data corresponding to Internet communication events even over a short period of time. The data analyst may pursue a data analysis path that involves applying a filter, joining to another table in a database, viewing a histogram, manipulating a pivot table, and finally viewing a summary of the entries located which match the parameters of the data analysis path. The summary may not provide the data analyst with the results she was hoping to find and thus she may decide to investigate another data analysis path. However, rather than start over from scratch, she may wish to return to another point in the first data analysis path. For example, perhaps while viewing the histogram she noted other points to explore later. 
     In an embodiment, a main data analysis workflow user interface provided by the data analysis system provides the data analyst with a set of highly interactive data visualization tools with which the data analyst can explore sets of data. Data visualization tools provided by the data analysis system can include, for example, a data summary view; a time series view; a time grid view; a heat map view; a pivot table view; an ability to link to another table in a database; and options to add, remove, or keep only selected results from a data view. 
     Each of these data visualization tools may include rich UI controls which are configured to respond to user interaction and input in a manner that allows the non-technical user to quickly and intuitively create complex data set queries. For example, in a histogram view data visualization UI, when a user selects (e.g., by clicking on, touching, speaking, etc.) a column in the histogram, a query filter may be automatically determined and applied to a subsequent query to be processed by the data analysis system. Or, in another example, an interactive heat map overlaid on a geographic region may allow the user to click and/or touch-and-drag to select a region of interest, and in response a query filter may be automatically generated which specifies the region of interest as a matching parameter. Subsequent queries may be easily built and executed to automatically apply the filter specified by the user interaction with the various data visualizations, providing a highly responsive, intuitive, and immersive user experience. 
     In one embodiment, the data analysis system maintains a session history for the analyst&#39;s data analysis paths and may provide various user interface features to allow the analyst to quickly and easily return to any prior point in the data analysis path, including the histogram view in the hypothetical example above. When a new data analysis path is started the session history is updated to include a new branch path from the original path. 
     As the analyst builds a data set query using these data visualization tools, the corresponding query result is added to the main data analysis workflow UI (for example, appended to the bottom of the workflow), and the session history is updated. This analysis interaction process may proceed over as many data set queries as the analyst wishes to investigate, with each subsequent query result added to the main data analysis workflow UI and the session history being updated. 
     In one embodiment, the main data analysis workflow UI provides the ability for the data analyst to scroll up or down within the current data analysis path, for example to re-display various data set query results and associated data visualizations appearing earlier in the current data analysis path (which, for example, may no longer fit in a displayable area of a display screen). The data analyst user may then decide to investigate a new data analysis path based on an earlier query result/visualization. 
     To assist the data analyst user in navigating these multiple data analysis paths, data query sets, and results, the data analysis system can provide a variety of path navigation user interface tools. For example, in one embodiment, an interactive breadcrumb path UI control may be generated and displayed (e.g., at the top of the main data analysis workflow UI, as shown in the example user interfaces herein; or in any position). Each “crumb” in the breadcrumb path UI control may indicate a summary of a respective data query and/or filter submitted over the course of the current data analysis path that is displayed in the main data analysis workflow UI. Further, each crumb may be selectable by the data analyst. Selecting a crumb may automatically update the main data analysis workflow UI to re-display the associated data set query and data visualization of the associated results. 
     In another embodiment, an interactive tree view UI control may be generated and displayed (e.g., at the right side of the main data analysis workflow UI, as shown in the example user interfaces herein; or in any position). Each “node” in the tree view path UI control may indicate a summary of the respective data queries submitted over the course of the current data analysis path that is displayed in the main data analysis workflow UI. For example, when a user positions a cursor or pointer over a node in the tree view, a popover UI element may appear next to the node, where the popover UI element includes a summary of the data query. Further, each node may be selectable by the data analyst. Selecting a node may automatically update the main data analysis workflow UI to re-display the associated data set query and data visualization of the associated results. The data analyst may then, for example, jump to another point, save the associated data set, or begin a new branched data analysis path. 
     The tree view UI control may be displayed in a variety of ways. In one embodiment, a single-path tree view UI control may be displayed corresponding to the current data analysis path. For example, suppose the current data analysis path (and the main data analysis workflow UI) includes a filter with a histogram view; a join with a table view; and a filter with a time series view. Then, the single-path tree view UI control may include one path comprising three nodes: filter-join-filter. In some embodiments the different associated data visualization elements may be indicated by representative icons, such the data analyst can view at-a-glance that the current analysis path comprises filter-join-filter. 
     In another embodiment, an all-paths tree view UI control may be displayed to present the user with all analysis paths explored for the current session. For example, suppose the current data analysis path is as described above with two additional branch paths: a heat map view branched from the join; and a time grid view branched from the first filter. Then, the all-paths tree view UI control may include five nodes corresponding to the three paths: filter-join-filter (the current path); filter-histogram; and filter-time grid. In one embodiment, the single-path tree view UI control may be displayed concurrently with the main data analysis workflow UI and display the current data analysis path. A user-selectable option to view the all-paths tree view UI control may be presented, and upon selection the all-paths tree view UI control may displayed such as in a popover UI element. The all-paths tree view UI control may be configured to support full user interaction in a similar manner to the single-path UI control. Thus, the data analyst may switch to the all-paths tree view UI control, select a node from the all-paths tree, and in response the main data analysis workflow UI will re-display the associated data set query and data visualization of the associated results. 
     The breadcrumb path UI control and the tree view path UI control can thus each be used to jump from any first point in the data analysis path to any second point in the data analysis path, with the main data analysis workflow UI being updated to match the selected point. However, in certain embodiments, when the user jumps from point to point in this manner, the associated data query may not need to be executed again. Rather, a cached copy of the previously generated data visualization may be re-displayed, or a cached copy of the associated data query results may be accessed and used to generate or update the data visualization. 
     The data analysis system described herein provides a variety of additional features and benefits. In certain embodiments, the data analysis system and provided user interfaces may enable the data analyst user to save data query set results at any stage in the analysis path; and/or export data query set results, for example to another database or another format such as a presentation software format (e.g., PowerPoint), as further described below. 
     Saving a data query set may allow the data analyst to return to an analysis path in progress at a later time for further exploration. In some instances the data query set may be saved such that the full analysis path taken to reach the particular data query set is saved as well, which can enable the analyst to re-explore the full path at a later time. In some cases, the data query set may be saved in a “clean” state, such that the analysis path taken to reach the particular data query set is not saved. This may be of benefit, for example, if the analysis path was particularly long or convoluted and saving the path provides little value to the analyst. The system may provide an option for the analyst to choose whether a data set should be saved with or without the full analysis path. 
     Several types or varieties of data sets may be saved in accordance with this feature. One example data set is a materialized saved set, which is a particular set of records that matches the exact set of records that an analyst currently observes, and can be retrievable in the same precise form at a later date. A materialized saved set may have different versions that are refreshable or updatable at a later date, and as such information can also be stored describing, among other things, how a refresh may be performed, when the last refresh was conducted, and who performed the refresh. Another example data set is a dynamic saved set, which is a workflow definition that will produce a set applying some saved criteria. Another example data set is a parameterized saved sets, which is a workflow definition that will produce a set applying some saved criteria against with sets of the same shape (e.g., column definitions) as the original saved definition input sets. Many other types of saved sets may be possible as well. 
     Exporting a data query set may allow the data analyst to extract a data query set, for example, for importing into another data source separate from the original, high-volume data source. This feature may be of particular benefit if, for example, the original, high-volume data source comprises data which is very noisy or may otherwise be of little value in more focused or specialized databases. Using the example above with reference to Internet proxy traffic data, the vast majority of such data is normal, everyday traffic which is likely not to be of particular interest. Rather than import the full set of Internet proxy data into a more specialized database, the data analyst can use the data analysis system herein to explore and filter down the high-volume data. Once a filtered data query set is obtained which appears to be of interest or relevance to the specialized database, the data set can be exported. 
     Another benefit to the export feature is that it may reduce the costs involved in maintaining and searching a high-volume data source by keeping that data source separate. For example, the cost (both financially and physical resource-wise in terms of memory, response time, processing speed, efficiency, power consumption, etc.) of maintenance, duplication, backups, and other redundancy measures for specialized databases can grow exponentially if copious amounts of noisy data are imported. Thus, using the data analysis system and export features herein, the specialized databases can remain specialized, while the high-volume data sources may still be explored to identify and extract valuable data. 
     The data analysis systems and methods described herein may also include various features for query optimization on the backend or server-side. For example, a query backend module may be configured to analyze user selections and interactions with the data set query results and associated data visualizations and, based on those selections and interactions, determine what data the user is actually interested in, and translate the query into an efficient or optimized search query string. For example, the user might produce a workflow or analysis path which involves linking or joining a first large data set to a second large data set, and then filtering the resulting linked data set. An optimized search query string may then be generated which applies the filter operation prior to the link or join operation, such that the resources required to perform the join operation would be greatly reduced (i.e., since the link or join operation would be performed on smaller data sets resulting from the filter being applied first). 
     Another query optimization feature which may be provided by the data analysis system includes logic to evaluate a query, such as a JOIN operation, will be and, based on the expense, determine whether a temp table should be created in order to improve the performance of subsequent queries using the data query result set. For example, in some cases a temp table may “cost” less in terms of computer processing or memory requirements than re-executing the JOIN operation. Another query optimization feature related to the use of such temp tables which may be provided by the data analysis system includes connection pooling, whereby temp tables may be mapped to different connections or users to facilitate efficient re-use of temp tables for the respective user&#39;s analysis workflow. These and other features described herein are of particular value in the context of processing and querying high-volume data, where physical hardware costs and resources are constrained. 
     In some embodiments, the data analysis system may be configured to defer execution of a query until a particular analytic view is rendered. This can provide additional efficiency, for example, when users are simply trying to construct complex set-based queries, and enables non-technical users to create complex queries without actually understanding the underlying query language (like SQL). Users might find benefit from the data analysis system as a tool that enables construction of complex reporting queries, even without visual feedback (but with the benefit of optionally including such visual feedback on demand). In some instances, the data analysis system may provide users with the ability to define filters without visual feedback, and do so incrementally and intuitively as a logical “next step” in a workflow for filtering, triaging, linking, and so on. 
     Example User Interfaces 
       FIGS. 1A-1D and 2A-2B  illustrate example user interfaces and UI components, as used in one or more embodiments of the data analysis system  100  of  FIG. 6 . The sample user interfaces may be displayed, for example, via a web browser (e.g., as a web page), a mobile application, or a standalone application. In some embodiments, the sample user interfaces shown in  FIGS. 1A-1D and 2A-2B  may also be displayed on any suitable computer device, such as a cell/smart phone, tablet, wearable computing device, portable/mobile computing device, desktop, laptop, or personal computer, and are not limited to the samples as described herein. The user interfaces include examples of only certain features that a data analysis system may provide. In other embodiments, additional features may be provided, and they may be provided using various different user interfaces and software code. Depending on the embodiment, the user interfaces and functionality described with reference to  FIGS. 1A-1D and 2A-2B  may be provided by software executing on the individual&#39;s computing device, by a data analysis system located remotely that is in communication with the computing device via one or more networks, and/or some combination of software executing on the computing device and the data analysis system. In other embodiments, analogous interfaces may be presented using audio or other forms of communication. In an embodiment, the interfaces shown in  FIGS. 1A-1D and 2A-2B  are configured to be interactive and respond to various user interactions. Such user interactions may include clicks with a mouse, typing with a keyboard, touches and/or gestures on a touch screen, voice commands, physical gestures made within a proximity of a user interface, and/or the like. 
       FIG. 1A  illustrates an example data analysis user interface  1000 A, as generated using one embodiment of the data analysis system  100  of  FIG. 6 . The data analysis UI  1000  may comprise, for example, a main data analysis workflow user interface for a user, such as a data analyst, to dynamically build data sets and queries and to view query set results. The query set results may be generated by the data analysis system  100  in response to user queries, and presented via highly interactive user interface UI display elements and controls. The data analysis UI  1000  may include a tree view UI control  102 A, breadcrumb UI control  104 A, and a data visualization UI element  106 , which in  FIG. 1  comprises a summary data view presenting a summary of data set results. Also shown is an action menu  108  which provides a list of data analysis tools and options available for the user, including: summary view; histogram; time series; time grid; heat map; pivot table; a set viewer; a table view; a pivot table; and options to save a set and to export a set. Additional actions and options not shown can also be included. In response to selection of these various data analysis tools the data analysis UI  1000  may be updated to add a new UI display panel presenting the selected analysis tool at the bottom of the workflow area. The user may then use the selected analysis tool to build and run a subsequent query to obtain a next data query result set. 
     Each time a selected data analysis tool is used by the user to build a query, the data analysis system  100  may update the associated session history for the user to track the user&#39;s analysis path. In some embodiments, the session history may be updated as the user builds the query, but before the query is executed, in order to capture the user&#39;s work in progress. In some embodiments, the session history may be updated when the query is executed and query results are obtained. As the session history is updated, the tree view UI control  102 A and the breadcrumb UI control  104 A may also be updated to reflect the updated analysis path. This is described in more detail with reference to  FIGS. 1B-1D  as the example workflow progresses; as well as with respect to the process  400  of  FIG. 4  herein. For example, the breadcrumb UI control  104 A may be appended with a description of the query parameters and/or type of operation performed (e.g., as may be indicated by an icon). Similarly, the tree view UI control  102 A may be updated to include an additional node on the current branch or path, corresponding to the additional analysis step (including either a query-in-progress or a query result set generated and added to the main workflow). 
     As the analysis path grows or the user begins to backtrack and create new branches, the tree view may become too large to persistently display in the main data analysis workflow user interface. Thus, in some embodiments, the tree view UI control  102 A-D may comprise a single series of nodes representing the current analysis path in the session. The tree view UI control  102 A-D may include an expand option which the user can select to view the full or expanded tree view. The full or expanded tree view may be presented as a popover UI control overlaid on the main data analysis workflow user interface or in a separate window or user interface. More detailed examples of the expanded tree view are illustrated and described with respect to  FIGS. 2A and 2B  herein. 
     With continued reference to  FIG. 1A , the hand cursor over the histogram icon in the actions menu  108  indicates that the user is selecting a histogram data visualization, which is illustrated and described next in  FIG. 1B . 
       FIG. 1B  illustrates an example data analysis user interface  1000 B, which may be a continuation of the workflow shown in user interface  1000 A. Once the user has selected the histogram option, a histogram menu  110  may be displayed by which the user can select one or more query parameters specifying the desired output result and format. Other data visualization elements described herein may have similar or other menu options for the user to specify query parameters for the respective data visualization. 
     When the user is satisfied with the selection, e.g., of count_distinct, hometown, country, and quantity parameters in the example of  FIG. 1B , the “compute” button may be selected. In response the data analysis system  100  receives the request and query parameters and processes a query against the current query result set. The output results may be used to generate the histogram data visualization and displayed in the main data analysis workflow user interface, as  FIG. 1B  shows. Also shown in user interface  1000 B, the view UI control  102 B may be updated to add an additional node indicating the histogram has been added to the current analysis path. In some embodiments, the visualization, e.g., the histogram, is updated in real time as the various parameters are each individually selected. 
     The histogram data visualization may be interactive and provide functionality for the analyst to quickly and intuitively begin developing another query. For example, in response to the user selecting one or more bars in the histogram, a query filter display  114 B may appear and dynamically update to include each of the one or more bars selected by the user. When the user wishes to continue the analysis beyond the histogram, another action may be selected from the action menu  108 B. If any query filter criteria are still selected from the user interaction with the histogram, these may be gathered and applied to the next query processed by the data analysis system for the current workflow. 
       FIG. 1C  illustrates an example data analysis user interface  1000 C, which may be a continuation of the workflow shown in user interface  1000 B. In this continued example of the workflow which started in  FIG. 1A , the data analyst has progressed a couple of steps further in the analysis path. The view UI control  102 C has been updated to indicate that subsequent to the histogram discussed above, a time series query was processed by the system and the associated time series data visualization (shown partially visible in the user interface  1000 C) was generated and displayed. At any point in the analysis the user may use the fully interactive view UI control  102 C to navigate to an earlier step in the analysis path; in response, the main data flow user interface may scroll up or otherwise cause re-presentation of the data visualization corresponding to the selected node. 
     The user interface  1000 C also demonstrates the breadcrumb UI control  104 C being updated to reflect the user&#39;s earlier selection from the histogram to filter on the country “USA.” As with the tree view UI control  102 C, the user may select any crumb in the breadcrumb UI control  104 C to navigate to the corresponding step in the analysis path. 
     The time series data visualization, like the histogram, may provide several interactive features. For example, in response to the user selecting a segment of the time series, the query filter display  114 C may dynamically update to specify a query filter corresponding to the user selection (here, a date range). As user interface  1000 C further illustrates, a summary view has been selected again by the data analyst so that she can assess at a glance whether the query filters applied so far in the analysis path have yielded any interesting query results. 
       FIG. 1D  illustrates an example data analysis user interface  1000 D, which may be a continuation of the workflow shown in user interface  1000 C. In this continued example of the workflow which started in  FIG. 1A , the analyst has selected a heat map data visualization element  116 . The view UI control  102 D has been updated to indicate that subsequent to the histogram and time series discussed above, a summary view, a pivot table, and finally the heat map currently displayed were processed by the data analysis system. As before, at any point in the analysis the user may use the fully interactive view UI control  102 D to navigate to an earlier step in the analysis path. 
     The user interface  1000 D also demonstrates the breadcrumb UI control  104 C being updated to reflect the user&#39;s earlier selection from the histogram to filter on the country “USA,” as well as several additional interim filters and operations which have been applied during the current analysis path. As with the breadcrumb UI control  104 C, the user may select any crumb in the breadcrumb UI control  104 D to navigate to the corresponding step in the analysis path. 
     The heat map data visualization, like the histogram and the time series, may provide several interactive features. For example, in response to the user drawing a circle or otherwise circumscribing an area on the map, the query filter display  114 C may dynamically update to specify a query filter corresponding to the user selection (here, a geographic range and a center point). 
     In the example shown, the user has selected a region roughly corresponding to the New England area, with New York as the center focus. For instance, the query results data may indicate a high degree of activity, such as Internet traffic, satisfying the query parameters in the New York area. The data analyst/user may quickly make this determination from studying the heat map, and then uses the map selector to zoom in on the region of interest. In response the data analysis user interface may interpret the user&#39;s map selection as a desire to build a new query and immediately add a query filter, shown below the map in this example, to filter the results to the selected region. The user can then select one of the actions  108 D and execute the query filter to view a subsequent data set, where the filter is applied to the query results from the heat map. 
       FIGS. 1E-1M  illustrate additional user interface features that may be implemented in some embodiments in order to selection actions, visualizations, and/or data sets upon which new visualizations should be generated. In this example, a text input control  123  receives text entry from the user in a natural language format; although in other embodiments the text entry may be in a coded, shorthand, or abbreviated format. The text entered by user may then be parsed by the system in order to predict another visualization of interest to the user and/or further filter parameters of interest to the user, such as that might be applied to another visualization. 
     For example, in the example of  FIG. 1E , the user has begun typing a query such as “show me count by day.” However, before finishing the text, each of the visualizations shown below the input control  123  are grayed out (e.g., not selectable) as the system is processing the text data to determine which visualization is associated with the provided text. In some embodiments, the system provides suggestions of visualizations/or filtering associated with those visualizations before an entire search string is entered. For example, the system may predict characters that are going to be typed by the user. Returning to the example in the figures, when the text has been entered, as in FIG. IF (or prior to completion of the full text query in some implementations), the dropdown list of visualizations is updated to provide one or more predicted or suggested data visualization elements relevant to the provided text entry. In the example of  FIG. 1F , the prediction or suggestion may be based on a real-time analysis of the user input and scanning for certain keywords which may indicate or otherwise suggest that the user is interested in a particular set of data which may be well suited for one or more data visualization types. For example, the word “count” in the user input may signal to the system that the user is probably interested in viewing a time series, and thus this particular data visualization option or thumbnail in the dropdown list may be highlighted so that the user can see that the “time series” data visualization is recommended and/or available for the particular user input or query. As another example, the user input may be “histogram rate code” which may in turn signal the system that the user is probably interested in viewing a histogram; then the histogram option or thumbnail may be highlighted for the user to more easily select. 
     The user can then select any of the available visualizations (e.g., time series in example of  FIG. 1 ) for display in the user interface, such as is shown in  FIG. 1G .  FIG. 1G  also includes an input control  123 B that provides the same or similar functionality to the input control  123 ; that is, free-form text may be entered in order for the system to predict which visualization the user is interested in viewing next and/or additional parameters for filtering the data set in the recommended visualizations. However, the visualization prediction provided in response to text provided into input control  123 B may further be influenced by the time series that was previously displayed in response to the previous selection made with reference to  FIG. 1G , for example. Thus, as with other examples discussed herein, filtering of the data set and subsequent visualizations based on such filtering may build upon one another in a sequential fashion to provide various granularities, types, and sets of information to the user in various available visualizations. 
     In the example of  FIG. 1H , the user has started typing a new free-form search query, but the system has not yet identified a most appropriate visualization and/or parameters for the visualization. Moving to  FIG. 1I , the user has completed entering “histogram rate code”, such that a histogram visualization is unlocked for selection, and the system has automatically determined that the “rate code” should be the main input parameter of the histogram. Thus, when the Histogram visualization is selected, a new visualization, such as in  FIG. 1J , including a histogram showing rate counts, is added to the user interface. 
       FIGS. 1K-1M  illustrate yet another example of parsing of free-form text in order to provide a particular visualization and primary attribute for display in the visualization. In this example, the user has indicated that a distribution visualization is desired, such that the system automatically begins precalculating (in some embodiments) a distribution visualization based on a “trip distance” parameter of the data set, resulting in display of the distribution visualization of  FIG. 1M  in response to the user&#39;s selection of the Distribution visualization (in  FIG. 1L ). 
     In some instances, the dropdown list (or other user interface display element listing one or more options for user selection) may display or include a hint for the user to indicate one or more keywords or data types which, if included in the text input, would enable or highlight the particular data visualization element. For example, the list may indicate that, for a pivot table, the system is “looking for” the keyword “across.” Then, if the user inputs the term “across” in the text input control, the system may infer that the user is interested in viewing a pivot table and correspondingly enable or recommend the pivot table data visualization. Other examples may include: Grid is looking for the keyword “an aggregate”; Histogram is looking for the keyword “hist”; Distribution is looking for the a data type of “a column,” and Time Series is looking for the keyword “time.” 
     Additional keywords may be used or suggested, and more than one keyword may be “looked for” by a particular data visualization to signal the system to generate, enable, or otherwise recommend the particular data visualization to the user. In addition, the data visualization highlighted or recommended by the system may change in real-time as the user provides more input. For example, the system may initially recommend one data visualization such as a Time Series in response to identifying the keyword “time” in the user input; but then update to recommended a different data visualization such as Pivot Table in response to identifying other keywords or structure to the user input that may indicate the user is more likely interested in something other than the initially recommended Time Series data visualization. 
       FIGS. 2A-2B  illustrates example data analysis path tree view user interfaces, as generated using one embodiment of the data analysis system  100  of  FIG. 6 . The tree view  202 A of  FIG. 2A  or the tree view  202 B of  FIG. 2B  may be displayed in response to a user selection from the main data workflow user interface. Nodes in each tree view  202 A,  202 B may be represented by icons indicating the types of query operations or data visualization performed or accessed at the particular node. For example, the tree view  202 A includes a summary node, a histogram node, a time series node, a pivot table node, and a summary node on each of two branches from the pivot table node. The tree view  202 A may correspond, for example, to some of the analysis path and tree view  102 C described in  FIG. 1C . 
     In  FIG. 2B , the tree view  202 B corresponds to the same analysis path represented in tree view  202 A but includes several additional nodes, indicating that the analysis path has grown. For example, the tree view  202 B includes the same nodes as tree view  202 A, with additional nodes for each of the two branches—namely a table view node and a histogram node. 
     As further illustrated in  FIG. 2B , popover UI elements  204 B may be displayed to show query detail (e.g., the associated query parameters and/or type of operation performed). The popover UI elements  204 B may be displayed to the right (or left, etc.) of the tree, such as when the user positions a pointer or cursor over a node in the tree view  202 A. In some embodiments, only some nodes of tree view  202 B display the associated query detail, perhaps indicating certain key nodes in the analysis path. For example, a node&#39;s query detail might be selected for display based on a user flag or marker indicating the query result was one of interest for later data exploration; or, the query detail might be selected for display based on a determination made by the data analysis system, such as a based on a number of results returned, or other factors. 
     In certain embodiments, the tree views  202 A,  202 B may be interactive such that the user may select a node in order to return to that point in the analysis path. Selection of the node may cause the main data analysis workflow user interface to re-display the associated data query set result and/or visualization control, which the user can view and optionally from which the user can launch a new analysis path. 
     Although the tree views  202 A and  202 B shown in  FIG. 2A-2B  illustrate two branched analysis paths for the current session, in certain embodiments other tree views may be generated to show any number of paths. For example, in one embodiment, a single-path tree view UI control may be presented to show only the current analysis path, for example in a side panel on the main data analysis workflow user interface. An expanded or all-paths tree view UI control may then be displayed in response to user selection of an option presented in one of the data system user interfaces to view the expanded or all-paths tree. In other instances, depending on the depth and complexity of the analysis path, the tree view UI may be generated to display only a local portion of the analysis path, or include a zoom in/zoom out feature to allow the user to navigate the tree view and different analysis path. 
     In various embodiments, the tree view represents a computation graph (for example, Directed Acyclic Graph) of input sets. Some operations take as input more than just the parent set, and thus form the nodes of a compute graph. Other compute graphs can be used as input at these junctions, and with the added feature of constructing saved sets, these compute graphs can be quite complicated. Thus, one benefit provided by the tree views discussed herein is to allow non-technical users to construct large compute graphs with semantically labeled sets. The data analysis system may be configured to perform some caching on the back-end to optimize the compute profile of particular graphs. This caching can be performed across multiple users, such that if multiple users request the same graph, the result of that compute graph may be cached for speedier or more efficient execution. Elements of the total computation may be optimized by replacing a particular node in the graph with its materialized saved set result (for example, in cases in which the materialization data set remains valid). 
     Examples of Processes Performed by Data Analysis Systems 
       FIGS. 3, 4, and 5  are flowcharts illustrating various embodiments of data analysis system processes. In some implementations, the processes are performed by embodiments of the data analysis system  100  described with reference to  FIG. 6  and/or by one of its components, such as the network service module  124 , the caching module  126 , the export service  128 , the import service  132 , and/or the query backend  134  shown in  FIG. 6 . For ease of explanation, the following describes the services as performed by the data analysis system  100 . The example scenarios are intended to illustrate, but not to limit, various aspects of the data analysis system  100 . In one embodiment, the processes can be dynamic, with some procedures omitted and others added. 
       FIG. 3  is a flowchart illustrating one embodiment of a process  300  for processing data set queries using an interactive data analysis user interface, as used in one embodiment of the data analysis system  100  of  FIG. 6 . Depending on the embodiment, the method of  FIG. 3  may include fewer or additional blocks and/or the blocks may be performed in an order that is different than illustrated. 
     At block  305 , the data analysis system  100  processes a data set query on a data set. The data set may be an unfiltered data set, such as a set of proxy data logs that the user wishes to analysis or may be a filter portion of a data set, such as a subset of the proxy data that was previously processed. 
     At block  310 , the data analysis system  100  generates and provides output results for the data set query, which may include an associated data visualization UI element such as those described herein. The output results and data visualization UI element may be displayed, for example, via one of the example user interfaces  1000 A-D discussed above. 
     At block  315 , the data analysis system  100  receives user interaction data for user interaction with the data visualization UI element. For example, the user may interact with the data visualization UI element by selecting one or more bars, lines, or other portions indicating a selection of some subset of the data represented by the data visualization. The selections may then be interpreted as query filters for a subsequent query result set. Several examples of these types of interactions are described with reference to  FIGS. 1A-1D . 
     At block  320 , the data analysis system  100  initializes generation of the subsequent query based on the user interaction data. For example, a query filter display may be presented and dynamically updated to include each of the user&#39;s selections. Once the user&#39;s selections have been received and the user elects to calculate or submit the query, the process  300  may return to block  305  and repeat again. In this way, the user can drill down (and/or up) in various manners to view different subsets of the data in various ways. 
       FIG. 4  is a flowchart illustrating one embodiment of a process  400  for generating an interactive breadcrumb and/or an interactive tree view representing a data analysis path for display in a data analysis user interface, as used in one embodiment of the data analysis system  100  of  FIG. 6 . Depending on the embodiment, the method of  FIG. 4  may include fewer or additional blocks and the blocks may be performed in an order that is different than illustrated. 
     At block  405 , the data analysis system  100  receives a request to execute a data set query on a current session or result set. The request may be received, for example, via one of the user interfaces  1000 A-D described previously, for example over the course of an analysis workflow. 
     At block  410 , the data analysis system  100  executes the data set query, for example by using the caching module  1226  and/or accessing the local data source  170  to run the query. Some or all of the query execution may be performed by, for example, the query backend  134 , which may apply some of all of the query optimization techniques described herein. 
     At block  415 , the data analysis system  100  accesses the output results and generates a UI element (e.g., a data visualization control) associated with the execution of the data set query. For example, the type of UI element generated may be based on a user selection from the actions menu  108  illustrated and described with reference to  FIG. 1A . 
     At block  420 , the data analysis system  100  maintains or updates a session history of the data set queries executed for the current session. The session history includes the query details associated with each respective data set query, such as query parameters and/or a type of operation performed. The query details may be used, for example, in order to provide a visual reminder to the user about the data set query, as well as to enable re-execution of the query in some instances. 
     At block  425 , the data analysis system  100  generates or updates an interactive breadcrumb UI control (such as the breadcrumb  104 A-D to display the summary of the query detail information for data set queries performed for the current analysis path. 
     At block  430 , the data analysis system  100  generates or updates an interactive tree view UI control (such as the tree view  102 A-D or  202 A-B), which may be configured to optionally display the summary of the query detail information for data set queries performed for the current analysis path (e.g., the query detail information may be displayed in response to a user interaction such as positioning a cursor, gesturing with a finger or hand near the screen, etc.). 
     Once the interactive breadcrumb and/or tree view UI controls have been updated, the user interfaces  1000 ,  2000  may be updated or refreshed to display the current view, and the user may continue to build and execute data set queries. 
       FIG. 5  is a flowchart illustrating one embodiment of a process  500  for navigating a data analysis path using an interactive breadcrumb and/or an interactive tree view representing the data analysis path in data analysis user interface, as used in one embodiment of the data analysis system  100  of  FIG. 6 . Depending on the embodiment, the method of  FIG. 5  may include fewer or additional blocks and the blocks may be performed in an order that is different than illustrated. 
     At block  505 , data analysis system  100  provides for display in a data analysis workflow user interface, an interactive breadcrumb and/or tree view UI element each of which may display summary information about data set queries performed for the current session, analysis path, or result set. 
     At block  510 , data analysis system  100  receivers a user selection of a session history node, such as a crumb in the breadcrumb or a node in the tree view. 
     At block  515 , data analysis system  100  updates the main workflow user interface to display the data set query and results corresponding to the selected session history node. 
     At block  520 , data analysis system  100  updates the interactive breadcrumb to display the data set queries or detail associated with the selected session history node. 
     At block  525 , data analysis system  100  updates the interactive tree view to provide an indication that the current position in the analysis path has changed, and to optionally display a new branch for the current session. 
     At block  530 , data analysis system  100  provides or updates the main workflow user interface as generated at block  515 , the interactive breadcrumb as updated at block  520 , and the interactive tree view at block  525 . 
     Example System Implementation and Architecture 
       FIG. 6  is a block diagram of one embodiment of a data analysis system  100  in communication with a network  160  and various systems, such as client computing systems(s)  168 , external data source(s)  172 . The data analysis system  100  may be used to implement systems and methods described herein, including, but not limited to the process  300  of  FIG. 3 , the process  400  of  FIG. 4  and the process  500  of  FIG. 5 . 
     Data Analysis System 
     In the embodiment of  FIG. 6 , the data analysis system  100  includes a network service module  124 , a caching module  126 , an export service  128 , an import service  130 , a query backend  134 , and a local data source  170 . 
     The security/single sign-on manager  122  provides capabilities to ensure that users are properly authenticated with the data analysis system  100 , as well as other security measures and protocols which may be used by the data analysis system  100 . 
     The network service module  124  provides capabilities related to generation, presentation, and in some cases display of the user interfaces, UI components, and related features, such as those illustrated and described with reference to  FIGS. 1A-1D and 2A-2D  herein. 
     The caching module  126  provides capabilities related to, among other things, caching of query results generated for analysis workflow sessions. The caching module  126  may also be configured to manage connection pooling for the data analysis system  100 , such that users of the system are mapped to temp tables created for their respective analysis workflows. Among other benefits this may help improve response times for the users as they may utilize the same connection and same temp tables many times over a single session. 
     The export service  128  processes requests to export data from the data analysis system  100  to, for example, the external data sources(s)  172 , working in association with the caching module  126  to access data and provide it to the network service module  124  for export. 
     The import service  132  may periodically poll or be notified by the external data source(s)  172  when new data may be available for import. When new data is available for import, the import service  132  may update the local data store  170  and provide an indication to the caching module  126  that new data is available. In response the caching module  126  may purge or invalidate outdated data. 
     The query backend  134  provides capabilities related to query optimization including analyzing query filters received from the network service module  124 . 
     Each of these components may be stored in a mass storage device as executable software codes that are executed by a central processing units (“CPU”). These and other modules in the data analysis system  100  may include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. In the embodiment shown in  FIG. 6 , the data analysis system  100  is configured to execute the modules recited above to perform the various methods and/or processes herein (such as the processes described with respect to  FIGS. 3, 4 , and  5  herein). 
     The data analysis system  100  and/or its subcomponents may include, for example, a server, workstation, or other computing device. In one embodiment, the exemplary data analysis system  100  includes CPUs, which may each include a conventional or proprietary microprocessor. The data analysis system  100  further includes one or more memories, such as random access memory (“RAM”) for temporary storage of information, one or more read only memories (“ROM”) for permanent storage of information, and one or more mass storage devices, such as a hard drive, diskette, solid state drive, or optical media storage device. Typically, the modules of the data analysis system  100  are connected to the computer using a standard based bus system. In different embodiments, the standard based bus system could be implemented in Peripheral Component Interconnect (“PCI”), Microchannel, Small Computer System Interface (“SCSI”), Industrial Standard Architecture (“ISA”), and Extended ISA (“EISA”) architectures, for example. In addition, the functionality provided for in the components and modules of data analysis system  100  may be combined into fewer components and modules or further separated into additional components and modules. 
     The data analysis system  100  and/or its subcomponents are generally controlled and coordinated by operating system software, such as Windows XP, Windows Vista, Windows 7, Windows 8, Windows Server, UNIX, Linux, SunOS, Solaris, iOS, Blackberry OS, or other compatible operating systems. In Macintosh systems, the operating system may be any available operating system, such as MAC OS X. In other embodiments, the data analysis system  100  may be controlled by a proprietary operating system. Conventional operating systems control and schedule computer processes for execution, perform memory management, provide file system, networking, I/O services, and provide a user interface, such as a graphical user interface (“GUI”), among other things. 
     Network 
     In the embodiment of  FIG. 6 , the data analysis system  100  is electronically coupled to a network  160 , which comprises one or more of a LAN, WAN, and/or the Internet, for example, via a wired, wireless, or combination of wired and wireless, communication link. The network  160  communicates with various computing devices and/or other electronic devices via wired or wireless communication links. 
     According to  FIG. 6 , in some embodiments information may be provided to or accessed by the data analysis system  100  over the network  160  from one or more external data source(s)  172 . The local data store  170  and/or external data source(s)  172  may include one or more internal and/or external data sources. In some embodiments, one or more of the databases or data sources may be implemented using a relational database, such as Sybase, Oracle, CodeBase, MySQL, and Microsoft® SQL Server as well as other types of databases such as, for example, a flat file database, an entity-relationship database, and object-oriented database, and/or a record-based database. 
     Other Embodiments 
     Each of the processes, methods, and algorithms described in the preceding sections may be embodied in, and fully or partially automated by, code modules executed by one or more computer systems or computer processors comprising computer hardware. The code modules may be stored on any type of non-transitory computer-readable medium or computer storage device, such as hard drives, solid state memory, optical disc, and/or the like. The systems and modules may also be transmitted as generated data signals (for example, as part of a carrier wave or other analog or digital propagated signal) on a variety of computer-readable transmission mediums, including wireless-based and wired/cable-based mediums, and may take a variety of forms (for example, as part of a single or multiplexed analog signal, or as multiple discrete digital packets or frames). The processes and algorithms may be implemented partially or wholly in application-specific circuitry. The results of the disclosed processes and process steps may be stored, persistently or otherwise, in any type of non-transitory computer storage such as, for example, volatile or non-volatile storage. 
     In general, the word “module,” as used herein, refers to logic embodied in hardware or firmware, or to a collection of software instructions, possibly having entry and exit points, written in a programming language, such as, for example, Java, Lua, C or C++. A software module may be compiled and linked into an executable program, installed in a dynamic link library, or may be written in an interpreted programming language such as, for example, BASIC, Perl, or Python. It will be appreciated that software modules may be callable from other modules or from themselves, and/or may be invoked in response to detected events or interrupts. Software modules configured for execution on computing devices may be provided on a computer readable medium, such as a compact disc, digital video disc, flash drive, or any other tangible medium. Such software code may be stored, partially or fully, on a memory device of the executing computing device, such as the programming notebook system  100 , for execution by the computing device. Software instructions may be embedded in firmware, such as an EPROM. It will be further appreciated that hardware modules may be comprised of connected logic units, such as gates and flip-flops, and/or may be comprised of programmable units, such as programmable gate arrays or processors. The modules described herein are preferably implemented as software modules, but may be represented in hardware or firmware. Generally, the modules described herein refer to logical modules that may be combined with other modules or divided into sub-modules despite their physical organization or storage. 
     The various features and processes described above may be used independently of one another, or may be combined in various ways. All possible combinations and subcombinations are intended to fall within the scope of this disclosure. In addition, certain method or process blocks may be omitted in some implementations. The methods and processes described herein are also not limited to any particular sequence, and the blocks or states relating thereto can be performed in other sequences that are appropriate. For example, described blocks or states may be performed in an order other than that specifically disclosed, or multiple blocks or states may be combined in a single block or state. The example blocks or states may be performed in serial, in parallel, or in some other manner. Blocks or states may be added to or removed from the disclosed example embodiments. The example systems and components described herein may be configured differently than described. For example, elements may be added to, removed from, or rearranged compared to the disclosed example embodiments. 
     Conditional language used herein, such as, among others, “can,” “could,” “might,” “may,” “for example,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment. The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. For example, a general purpose computer comprising one or more processors should not be interpreted as excluding other computer components, and may possibly include such components as memory, input/output devices, and/or network interfaces, among others. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list. Conjunctive language such as the phrase “at least one of X, Y and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require at least one of X, at least one of Y, and at least one of Z to each be present. 
     The term “a” as used herein should be given an inclusive rather than exclusive interpretation. For example, unless specifically noted, the term “a” should not be understood to mean “exactly one” or “one and only one”; instead, the term “a” means “one or more” or “at least one,” whether used in the claims or elsewhere in the specification and regardless of uses of quantifiers such as “at least one,” “one or more,” or “a plurality” elsewhere in the claims or specification. 
     While certain example embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Thus, nothing in the foregoing description is intended to imply that any particular element, feature, characteristic, step, module, or block is necessary or indispensable. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions, and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions disclosed herein. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of certain of the inventions disclosed herein. 
     Any process descriptions, elements, or blocks in the flow diagrams described herein and/or depicted in the attached figures should be understood as potentially representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process. Alternate implementations are included within the scope of the embodiments described herein in which elements or functions may be deleted, executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those skilled in the art. 
     It should be emphasized that many variations and modifications may be made to the above-described embodiments, the elements of which are to be understood as being among other acceptable examples. All such modifications and variations are intended to be included herein within the scope of this disclosure. The foregoing description details certain embodiments of the invention. It will be appreciated, however, that no matter how detailed the foregoing appears in text, the invention can be practiced in many ways. As is also stated above, it should be noted that the use of particular terminology when describing certain features or aspects of the invention should not be taken to imply that the terminology is being re-defined herein to be restricted to including any specific characteristics of the features or aspects of the invention with which that terminology is associated. 
     Additional Embodiments 
     Additional embodiments of the data analysis system  100  include features that may correspond to refreshing one or more nodes in a data analysis graph, modifying a data analysis graph, determining and/or presenting an abridged data analysis graph, a user interface for editing data corresponding to one or more nodes in a data analysis graph, a user interface for constructing one or more joins, a report user interface, a chart user interface, and/or an expression language for modifying a data node in a data analysis graph. The systems and methods described herein may improve existing computer technology and/or may be intrinsically tied to computer technology. Moreover, the systems and methods described herein may improve upon existing graphical user interfaces. 
     A data analysis graph may correspond to a data structure that represents the interactive data analysis user interfaces of the data analysis system  100 , as described herein. There may be advantages for the systems and methods described herein to correspond to an immutable data model. A non-limiting example advantage of immutability is the ability to efficiently backtrack, e.g., using breadcrumbs and/or an undo/redo function, in a data analysis graph or path based on immutable nodes (for example, since every user interface selection is represented by a new versioned node, backtracking may be efficiently determined by following the data analysis graph and accessing previous versions of nodes and/or by following the current traversal within the data analysis graph). In the example, each step of the data analysis graph is represented by an immutable node, where each node is a data structure representation of (i) the user interactions with the user interfaces described herein and/or (ii) the data sets of the user interfaces described herein. The example immutable nodes may include the user interface options and the underlying data sets of the data analysis system  100 . In the example, the nodes are immutable in that once they are generated they may not be deleted or updated. The example nodes are stored in the data source  170  and/or another data source of the data analysis system  100 . However, performing certain actions such as refreshing data sets and/or modifying data analysis graphs (e.g., inserting a new node) may be technically challenging where the nodes are immutable. 
     The technical solutions described herein to implement features such as refreshing data sets and/or modifying data analysis graphs, such as in the context of immutable nodes, may correspond to generating one or more duplicate nodes from a data analysis graph, generating updated nodes, and linking at least some of the one or more duplicate nodes with the updated nodes in a new graph, thereby giving the illusion of refreshing or modifying, among other details, which are described in further detail herein. In the example, dynamically refreshing a data set and/or data analysis graph may be accomplished by determining an active path in the data analysis graph, copying one or more nodes in the active path, identifying or generating an updated version of the original data set as a new node, and the new node is linked to at least some of the copied one or more nodes, which provides the illusion of refreshing the data set. If a dataset is refreshed the graph can be refreshed as well. The active path can be duplicated and the starting node can point to the refreshed version of the dataset. As another example, inserting a new node (for example, a visualization node) in an existing data analysis graph may be accomplished by inserting an intermediate node in an existing graph and then copying the children nodes to the branch with the intermediate node. The technical solutions regarding improved computer graph nodes is described in further detail with respect to  FIGS. 15 and 16 . 
     Terms 
     In order to facilitate an understanding of the systems and methods discussed herein, a number of terms are defined below. The terms defined below, as well as other terms used herein, should be construed to include the provided definitions, the ordinary and customary meaning of the terms, and/or any other implied meaning for the respective terms. Thus, the definitions below do not limit the meaning of these terms, but only provide example definitions. 
     Data Analysis Graph: Any data structure including one or more nodes that correspond to workflow user interfaces. Two or more nodes in the data structure may be connected and/or linked. One example data analysis graph is a tree data structure. In some embodiments, an example data analysis graph has two or more parent nodes. In the context of a data analysis graph: a “root node” is a top node in a graph; a “child node” and/or “sub-node” is a node that directly descends from a higher node; a “parent node” is the converse of a child; a child node has a “dependency” on a parent node; and a “descendent” is a node reachable by traversing from parent to child. A parent node may have one or more children. In some embodiments, an example data analysis graph is a directed graph and/or a directed acyclic graph. As described herein, the data structure can be visually represented in a user interface as a workflow. Further, the example data structure includes data representing user interactions with the workflow user interfaces and/or the data sets of the user interfaces. The terms “data analysis graph,” “graph,” “computer graph,” and “tree view” may be used interchangeably and/or synonymously in the present disclosure. A data analysis graph may include two or more connected data analysis graphs. An abridged data analysis graph corresponds to a subset of two or more nodes from a data analysis graph. In some embodiments, the abridged data analysis graph excludes nodes that are non-transformative and/or do not modify data. In some embodiments, the abridged data analysis graph includes data set nodes and/or nodes that transform data and/or correspond to a source data set. The terms “abridged data analysis graph” and “data set recipe” may be used interchangeably and/or synonymously in the present disclosure. 
     Node (Data Node): Any data structure representation of user interactions with the user interfaces described herein and/or the data sets of the user interfaces. A node may be linked to one or more other nodes. In some embodiments, the link between two nodes can be directed. A node may include configuration data regarding the presentation of its underlying data set. In some embodiments, a node is immutable. However, in other embodiments, the data of a node may be modified. The terms “node,” “data node,” and “board” may be used interchangeably and/or synonymously in the present disclosure. 
     Active Path: One or more nodes of a data analysis graph. The active path represents a user&#39;s current and/or previously traversed workflow. In an example where the active path contains two or more nodes, the active path also contains the connected edges and/or links of the two or more nodes. The terms “active path” and “data analysis path” may be used interchangeably and/or synonymously in the present disclosure. 
     Additional Example User Interfaces 
       FIGS. 7-14  illustrate additional example user interfaces of the data analysis system  100 , according to some embodiments of the present disclosure. In various embodiments, aspects of the user interfaces may be rearranged from what is shown and described below, and/or particular aspects may or may not be included. 
       FIG. 7  illustrates an example user interface  700  that presents a visualization of an example data analysis graph. The example user interface  700  may be similar to other user interfaces described herein, such as the user interfaces described in further detail with respect to  FIGS. 1A-1M . For example, the user interface  700  includes elements  702 A- 702 D that correspond to respective nodes from the data analysis graph. The example user interface  700  further includes control  706  that presents a summary of the data analysis path with respective visualization indicators (e.g., icons) for each node of the data analysis path. Accordingly, the example user interface  700  presents a workflow visualization to the user. As illustrated, the user interface  700  includes a view control  704  that when selected by user causes the data analysis system  100  to present an abridged data analysis graph, as described herein. 
     As described herein, example nodes may correspond to summary, table, histogram, distribution, time series, grid, heatmap, pivot table, filter, column editor, enrich, link, set math, export, and/or chart visualization. The following are descriptions of example nodes. 
     Summary Node: The example summary node presents the number of entries, such as rows, in the data set for the node. Additional features of the summary node include other configurable metrics that may be determined by the data analysis system  100  for the data set, such as unique values for a column; an average, standard deviation, variance, or any other statistical measure for a column, and/or a range for a column (such as a date range for a date column). 
     Table Node: An example table node may present a table or column view of the data set for the node. In an example table view, a configurable number of entries (such as the first 1,000) may be presented within the table node. In an example column view, column summary data may be presented for each column in the data set, such as column summary metrics including a percentage of null values, number of distinct values, and/or statistical measures such as the minimum, maximum, mean, or some of all values (in a numerical column). In some embodiments, the metrics may be precomputed or dynamically computed based on a user selection. 
     Histogram Node: An example histogram node aggregates the distinct values in a given column and displays the results as a chart, such as a bar chart. For example, a histogram may determine the average length of a taxi ride by which Chicago neighborhood it started in. 
     Distribution Node: An example distribution node presents the distribution of a numerical variable for an aggregate metric. The example distribution node may be similar to the histogram node, but may present aggregated data based on ranges of values, rather than specific values. In one example, a distribution node presents data about individuals” ages and ages are divided into ten ranges (or “buckets”). 
     Time Series Node: An example time series node allows a user to group data by time intervals and calculate aggregate metrics on that data. In one example, given a data set with personal information about individuals, the time series node computes the number of people born on each day. 
     Grid Node: An example grid node may be similar to the histogram node, but the grid node aggregates data by two columns rather than one, and presenting a heat grid chart of the results. In some embodiments, for more than two columns, an example pivot table node may be used. In one example, a grid node compares education level to yearly income. The example grid node may be similar to the following SQL query: “SELECT [x-axis-column], [y-axis-column], &lt;AGGREGATE_METRIC&gt;([aggregate-column]) FROM &lt;PARENT_NODE&gt; GROUP BY [x-axis-column], [y-axis-column].” 
     Heatmap Node: An example heatmap node presents geocoded data on a map, which may be color-coded to represent the values. In some embodiments, the heatmap dataset may include coordinate data that may correspond to latitude and longitude data or a geohash. 
     Pivot Table Node: An example pivot table node may enable a user to efficiently compute multiple aggregate values of a data set across multiple dimensions. In one example, given a dataset with demographic information about individuals, an example pivot table computes how many individuals (by age) are married females, married males, single females, or single males. 
     Filter Node: An example filter node applies customizable filters to the dataset for the node. In some embodiments, although a user may apply filters in other nodes (e.g., distribution, histogram), an example filter node allows a user to compile complex filters involving multiple variables in a single node. In an example filter node, if a user uses a list, the list may be similar to a “WHERE IN (x,y,z)” clause in SQL. The example filter node can efficiently handle lists of thousands of items (or larger). 
     Column Editor Node: The column editor node enables a user to remove columns from the corresponding data set and add new columns. Subsequent nodes will consume the resulting set of columns from the column editor Node. Removing columns via the example column editor node is similar to selecting column names in SQL. For example, given a table that has 5 columns, A-E, the following SQL statement, which is similar to the corresponding column editor operation, removes columns D and E: “SELECT columnA, columnB, columnC from tableName”. Adding columns via the example column editor node is similar to using operators in SQL. For example, the following SQL statement, which is similar to the corresponding column editor operation, adds a new column for Income per person: “SELECT [Household Members], [Marital Status], [Income Column]/[Household Members] AS [Income per person] FROM [Table Name]”. 
     Enrich Node: An example enrich node enables a user to join the current data set to another data set, and merge the matching results into the current data set. An example enrich node is described in further detail with respect to  FIG. 13 . 
     Link Node: An example link node enables a user to join to another (linked) set and return the results of that linked set. In some examples, the link node is used when data has been reduced to a set of keys that one would like to apply to another data set. For example, a user may have narrowed a list of suspicious individuals down to a few names, and the user would further want to look up those names in a different dataset containing personal information (address, phone number, etc.). Linking the rows in the original data set will select all the rows in the other dataset that match on a specified key (in this example, the key is the name). The following SQL statement may be similar to the link node operation: “SELECT [DISTINCT] &lt;RightTable.Column1, RightTable.Column2, . . . &gt; FROM (SELECT DISTINCT&lt;join keys&gt; from LeftTable) AS LeftTableKeys INNER JOIN RightTable ON &lt;join condition  1 &gt; ([AND|OR] &lt;join condition  2 &gt; [AND|OR] &lt;join condition 3&gt; . . .)”. 
     Set Math Node: An example set math node enables a user to alter the current data set based on another set. Thus, a user can filter the data set to keep data that exists in the other dataset (e.g., “keep only”), append data from another dataset (“add”), and/or remove data based on the results of another dataset (“remove”). An example set math node is the set math node  920  of  FIG. 9 . The example “keep only” operation filters records in the current data set to records that either appear in or match (“match on”) another data set. The “keep only-match on” operation may be similar to the left semi-join statement in SQL, such as: “SELECT L.* FROM L INNER JOIN (SELECT DISTINCT &lt;join column&gt; FROM R) AS R_KEY ON L.&lt;join column&gt;=R_KEY.&lt;join column&gt;”. The “add” operation adds records from another data set to the current data set. The example “add” operation may be similar to the union statement in SQL. The example “remove” operation removes records in the current data set that either appear in or match (“match on”) another data set. The “remove-match on” operation may be similar to the left outer join statement where the join keys do not match in SQL, such as: “SELECT L.* FROM L LEFT OUTER JOIN R ON L.&lt;join column&gt;=R.&lt;join column&gt; WHERE R.&lt;join column&gt; is null”. 
     Export Node: An example export node enables a user to download the current data set in one or more formats such as a delimited format (e.g., CSV) or a spreadsheet data format. 
     Chart Node: An example chart node enables a user to generate a chart. An example chart node is described in further detail with respect to  FIG. 14 . 
       FIG. 8  illustrates an example user interface  800  that presents a visualization of an example abridged data analysis graph. In the example, the data analysis system  100  presents the abridged data analysis graph in response to a user selection of the view control  704  of  FIG. 7 . Accordingly, the example abridged data analysis graph of  FIG. 8  corresponds to the example data analysis graph of  FIG. 7 . The example abridged data analysis graph includes the nodes  802 ,  804 ,  806 ,  808 ,  810 ,  812 , and  814 . As described herein, the example abridged data analysis graph corresponds to the nodes of a data analysis graph that correspond to data sets and/or transformations of data sets. Continuing with the example, non-transformation nodes and/or data set nodes would be removed in the presentation of the abridged data analysis graph. 
     In  FIG. 8 , the abridged data analysis graph begins with node  802  that corresponds to a data set of phone call records. From node  802 , the next node  804  is a pivot table operation that transforms the data set from node  802  to keep records with a caller country code  252  (for Somalia) and a callee country code 1 (for the United States). From node  804 , the next node  806  is a time series operation that further transforms the data set from node  804  to keep records with a call date between “Dec. 02, 2016 12:00 AM” and “Dec. 07, 2016 11:59 PM”. From node  806 , the next node  808  is a geographic map operation that transforms the data set from node  806  advantages to keep records with geographic locations within 30 km of the latitude and longitude coordinates of 46.72 degrees and −94.69 degrees (which roughly corresponds to New York City). The abridged data analysis graph also includes node  810  that corresponds another data set of phone call records. From node  810 , the next node  812  again is a pivot table operation that transforms the data set from node  810  to keep records with a caller country code  252  (for Somalia) and a callee country code 1 (for the United States). From node  812 , the next node  814  is a time series operation that further transforms the data set from node  812  to keep records with a call date between “Nov. 15, 2016 12:00 AM” and “Nov. 17, 2016 11:59 PM,” which is a different time frame than the time frame of node  806 . 
       FIG. 9  illustrates an example user interface  900  that presents a continuation of the visualization for the example abridged data analysis graph shown in  FIG. 8 . For example, the nodes  808 ,  810 ,  812 , and  814  of  FIG. 8  correspond to the nodes  908 ,  910 ,  912 , and  914  of  FIG. 9 , respectively. Continuing with the example of  FIG. 8 , from node  914 , the next node  916  is a geographic map operation that transforms the data set from node  914  to keep records with geographic locations within 1 km of the latitude and longitude coordinates of 34 degrees and −118 degrees (which roughly corresponds to Los Angeles). From node  916 , the next node  918  is a save operation to store the data set from node  916  as “Suspicious LA Calls.” From node  918 , the next node  920  is a set math operation to keep records that “match on” the column “Caller Phone Number” to the saved data set “Suspicious LA Calls” from node  918 . In some embodiments, the set math operation at node  920  merges matching records from the “Suspicious LA Calls” data set at node  918  and the data set from node  908 . 
     Advantages of the abridged data analysis graph shown in  FIGS. 8 and 9  include presenting a condensed and/or efficient view of the current data analysis path. For example, the data analysis graph shown in  FIG. 7  includes many non-transformation and/or non-data-set nodes. Accordingly, it may be difficult for a reviewer of the data analysis graph of  FIG. 7  to efficiently understand the particular operations that resulted in the current data analysis paths and/or data sets. In contrast, the abridged data analysis graph shown in  FIGS. 8 and 9  condenses the presentation of nodes to the nodes that correspond to the underlying data sets and/or the transformation nodes that manipulate those data sets. Thus, the presentation of the abridged data analysis graph provides an efficient view of the data analysis path. 
     In some embodiments, paths can be linked. A new path can be started from the resulting path of another path, such as by a user. The user can link, enrich, and/or join to the resulting set of a path just like dataset. A user can add layers in charts from resulting sets of other paths. 
       FIG. 10  illustrates an example user interface  1000  that presents a data analysis workspace. The data analysis workspace enables a user to organize multiple data analysis graphs. For example, a user may group two or more data analysis graphs that bear some relation to one another. The data analysis workspace may include some of the following features. As illustrated, the data analysis workspace includes a first presentation area  1002 , which presents a visualize summary of a first data analysis graph, and a second presentation area  1020 , which presents a visualize summary of a second data analysis graph. The first presentation area  1002  includes elements  1004 ,  1006 ,  1008 ,  1010 ,  1012 , and  1014  that correspond to nodes of the first data analysis graph. Another feature of the example workspace is to provide a staleness alert  1016  that when selected by a user causes the data analysis system  100  to refresh the node, as described herein. Another advantage of the example workspace is to enable a user to generate a report from data from one or more data analysis graphs (reports from multiple data analysis graphs are supported). 
     In some embodiments, the refresh control  1016  can override the logic that creates a new data set in the external data source(s)  172  corresponding to the resulting set of a path in a data analysis graph. In other words, a user can save the resulting set of a path in a data analysis graph to a new data set in the external data source(s)  172 . If a user changes the path in a data analysis graph, the logic may be out of date. Accordingly, user selection of the refresh control  1016  can update the logic to create that new data set in the external data source(s)  172 . 
     In some embodiments, the data analysis workspace of user interface  1000  enables a user to open a data analysis graph, such as the example data analysis graph  1002 . As described herein, presentation of a data analysis graph may correspond to the user interfaces described in further detail herein with reference to  FIGS. 1A-1M and/or 7 . Continuing with the example, a user may select a presented node, such as the nodes from  FIGS. 1A-1M and/or 7 , to further edit the data set for the node. For example, the data analysis system  100  may enable a user to edit the data set corresponding to the table node  1008  of  FIG. 10 . 
       FIG. 11  illustrates an example user interface  1100  that enables a user to edit a data set. The example user interface  1100  includes function selectors  1102 A- 1102 L. The example function selectors include an undo function selector  1102 A, a redo function selector  1102 B, a filter function selector  1102 C, a find and replace function selector  1102 D, an obfuscate function selector  1102 E, a mask function selector  1102 F, a parse dates function selector  1102 G, a remove characters function selector  1102 H, a combine column function selector  1102 I, a remove column function selector  1102 J, a rename column function selector  1102 K, and a split column function selector  1102 L. In some embodiments, the example user interface  1100  includes other spreadsheet functions. The example user interface  1100  further includes columns  1104 A- 1104 I and rows that represent the data set for the node. As illustrated, user selection of the obfuscate function selector  1102 E as applied to the “Type_1” column  1104 C causes the data analysis system  100  to obfuscate the data. An example of anonymization of data includes the data analysis system  100  replacing original data values with replacement data values. An example replacement data value is a randomized or pseudo-randomized character and/or number string, such as a hash string and/or a Globally Unique Identifier (GUID). The example user interface  1100  further includes summary representations of applied functions, such as the summary element  1106  that indicates that the obfuscate function was applied to the “Type_1” column  1104 C. In some embodiments, the user interface  1100  can show the entire path. The save selector  1110  enables a user to save the modifications to the data set. Additionally or alternatively, the user interface  100  can include an autosave feature. Accordingly, in some embodiments, the user interface  100  does not include the save selector  1110 . As described herein, modifications to the data set may be saved as a new node in the data analysis system  100 . 
       FIG. 12  illustrates an example report user interface  1200  that enables a user to generate a dynamic and/or interactive report from one or more data analysis graphs. The example report includes charts  1206  and  1208 , and text elements  1202 ,  1204 , and  1208 . The example text elements  1202 ,  1204 , and  1208  are headers or chart descriptors that are editable by a user. A user may add or remove charts. Example charts include bar charts, multi-bar charts, line charts, scatter plot charts, pie charts, tables, pivot tables, and/or other types of charts. The example chart  1206  is interactive where a user may zoom in, zoom out, click and drag, and/or obtain additional information for the entire chart or portions of the chart. Example additional information is the element  1207  that is presented based on a user selection of the x-axis of the example chart  1206 . The example chart  1206  can be dynamic in that if the underlying data set for the chart has been updated, then the data analysis system  100  presents the chart  1206  with a staleness indicator that a user may select to automatically refresh the chart, as described herein. In some embodiments, a user can set the whole report to auto-refresh whenever there is new data and/or the staleness indicator may not be shown. 
     While not illustrated in  FIG. 12 , in some embodiments, the report user interface  1200  may include additional features. A user may view the data in a chart in a table below the chart. A user may filter the data in the table by making a selection in the chart. A user may export the table to another format, such as a delimited format that includes CSV. A user may generate a new analysis graph from the chart where the path from root up to that chart will be copied and added to a new analysis graph and/or workspace for further exploration. 
       FIG. 13  illustrates an example user interface  1300  with a data analysis path that includes an example enrich node interface  1302 . As described herein, an example enrich node enables a user to join the current data set to another data set, and merge the matching results into the current data set. As illustrated, a user can select join selector  1304  that includes the example “left join,” “inner join,” or a “right join” options. 
     An example inner join generates a new data set by combining two data sets that satisfy the join condition. An example left join (or left outer join) similarly generates a new data set by combining two data sets; however, for data sets A and B, the generated data set contains entries of the “left” data set (A), even if the join condition does not find any matching entry in the “right” data set (B). The example left join returns the entries from an inner join plus the entries in the left table that do not match to the right table, in some cases, this includes entries with NULL (empty) values. An example right join (or right outer join) generates a new data set by combining two data sets and in a similar manner as the left join, except that the data sets (A and B) are reversed. The inner, left join, and right join operations of the enrich node may be similar to the following SQL equivalent: “SELECT [DISTINCT] &lt;Column1, Column2, . . . &gt; FROM CurrentTable &lt;INNER JOIN|LEFT OUTER JOIN|RIGHT OUTER JOIN&gt; OtherTable ON &lt;join condition 1&gt; ([AND|OR] &lt;join condition 2&gt; [AND|OR] &lt;join condition 3&gt; . . . )”. 
     The example enrich node interface  1302  includes the current data set  1306  and the “right” data set  1308  to be joined. In the example, the “Choose column” selectors enable a user to select a respective column from each data set to perform the join condition such that each respective column is used as a key. A user may add additional join conditions with the add condition selector  1310 . In some embodiments, if a user selects to join multiple keys, the interface  1302  provides a “Match Any” and/or “Match All” conditions. The join column selector  1312  enables a user to select the columns from the other set to add to the resulting data set. Accordingly, a user can join two or more data sets using the enrich node interface  1302 . 
     While not shown in  FIG. 13 , in some embodiments, the user interface  1300  can include a join user interface board that allows a user to choose from a list of fully pre-configured joins that can specify the dataset to join on, what key to join on, and/or what join type, with descriptions for ease of use. 
       FIG. 14  illustrates an example user interface  1400  with a data analysis path that includes an example chart node interface  1420 . As described herein, an example chart node enables a user to generate a chart from the current data set. As illustrated, a user can select multiple options to generate a chart. For example, a user can select the chart type selector  1404 . Example chart types include a multi-bar chart, a line a chart, a scatter plot chart, a pie chart, and/or other charts. In the multi-bar chart example, the chart node interface  1420  includes an x-axis selector  1406 , a segment by selector  1408 , and a y-axis selector  1410 . In some embodiments, the user interface corresponding to the chart node includes functionality similar to pivot table capabilities of spreadsheet applications. 
     In the example of  FIG. 14 , a user has selected a multi-bar chart for IP addresses as grouped by server location. The example chart visualization  1412  presents the IP address data as grouped by server location and indicates throughput (in megabytes, for example) in the y-axis and by date in the x-axis, which may correspond to the user selections of the chart type selector  1404 , the x-axis selector  1406 , the group by selector  1408 , and the y-axis selector  1410 . Additional example chart types that can be selected in the chart type selector  1404  include clustered bar charts, stacked bar charts, and relative bar charts, such as one hundred percent bar charts. 
     While not shown in  FIG. 14 , in some embodiments, additional layers can be added to a chart, such as a line overlaying bars, and presented in the user interface  1400 . The new one or more layers can be configured in tabs in the configuration panel. Each layer can define the data source it uses, either the data in the current node in the current path or the resulting set of another data analysis graph or another data set. 
     Example Data Analysis Graph 
       FIGS. 15A-15E  depict example representations of data analysis graphs, which may have been generated by the data analysis system  100 . With respect to  FIG. 15A , the data environment  1500  includes an example data analysis graph  1501 A at a first time (such as T=0). The example data analysis graph  1501 A includes nodes  1502 ,  1504 A,  1506 A, and  1508 A. As described herein, the nodes  1502 ,  1504 ,  1506 A, and  1508 A are data structure representations of the user interactions and/or the data sets of the user interfaces described herein, such as any of the user interfaces described with reference to  FIGS. 1A-1M and/or 7-12 . For example, each of the nodes  1502 ,  1504 ,  1506 A, and  1508 A may correspond to visualizations described herein, such as a summary, table, histogram, distribution, time series, created, heatmap, pivot table, filter, column editor, enrich, link, set math, and/or export visualization. 
     In some embodiments, each of the nodes  1502 ,  1504 ,  1506 A, and  1508 A may be stored in one or more data formats. As described herein, the data analysis system  100  may treat each of the nodes as immutable. An example data format of the nodes  1502 ,  1504 ,  1506 A, and  1508 A is a JavaScript Object Notation (JSON) data format. Accordingly, each of the example nodes  1502 ,  1504 ,  1506 A, and  1508 A is stored in a file. Additionally or alternatively, other example data formats include a database format, eXtensible Markup Language (XML), or a format that is proprietary to the data analysis system  100 . 
     With respect to  FIG. 15B , the data environment  1520  includes an example data analysis graph  1501 B. The example data analysis graph  1501 B may be similar to the example data analysis graph  1501 A of  FIG. 15A . For example, the example data analysis graph  1501 B corresponds to the same data analysis graph  1501 A but at a second time (such as T=1). Continuing with the example, the node  1504 A is immutable (and the other nodes as well); accordingly, if there is an update in the node configuration corresponding to the node  1504 A the data analysis system  100  generates a new node  1510  with the updated node configuration. A change to the node configuration can result in a duplicate node with child nodes propagated. In the example, the data analysis system  100  further duplicates the remaining nodes  1506 A and  1508 A to result in the duplicate nodes  1506 B and  1508 B. Accordingly, the path of the data analysis graph  1501 B corresponding to nodes  1502 ,  1510 ,  1506 B, and  1508 B may be presented to the user, which provides the changes in node configurations corresponding to the original path  1502 ,  1504 A,  1506 A, and  1508 A, but a new set of nodes have been generated where one of the nodes has the refreshed data. In the example corresponding to  FIGS. 15A and 15B , the immutableness of the data model is not violated. 
     With respect to  FIG. 15C , the data environment  1530  includes an example data analysis graph  1501 C. The example data analysis graph  1501 C may be similar to the example data analysis graph  1501 B of  FIG. 15B . For example, the example data analysis graph  1501 C corresponds to the same data analysis graph  1501 B but at a third time (such as T=2). Continuing with the example, the node  1506 B is immutable (and the other nodes as well); accordingly, if there is a change to the node configuration corresponding to the node  1506 B the data analysis system  100  generates a new node  1512  with the updated data. In the example, the data analysis system  100  further duplicates the remaining node  1508 B to result in the duplicate node  1508 C. Accordingly, the path of the data analysis graph  1501 C corresponding to nodes  1502 ,  1510 ,  1512 , and  1508 C may be presented to the user, which provides the changes in node configurations corresponding to the previous path  1502 ,  1510 ,  1506 B, and  1508 B. Again, in the example corresponding to  FIGS. 15A-15C , the immutableness of the data model is not violated. 
     With respect to  FIG. 15D , the data environment  1540  includes an example data analysis graph  1501 D. The example data analysis graph  1501 D may be similar to the example data analysis graph  1501 C of  FIG. 15C . For example, the example data analysis graph  1501 D corresponds to the same data analysis graph  1501 C but at a fourth time (such as T=3). Continuing with the example, a user may add a new visualization (or any available action or step in the data analysis system) to the active path. Accordingly, a new node  1514  corresponding to the new visualization is added to the data analysis graph  1501 D. Moreover,  FIG. 15D  further illustrates that the data analysis system  100  identifies the current active path  1516  that includes nodes  1502 ,  1510 ,  1512 ,  1508 C, and the new node  1514 . Accordingly, the active path  1516  may be presented to the user, which may correspond to any of the user interfaces described in further detail with respect  FIGS. 1A-1M, 7 , and/or  10 . Again, in the example corresponding to  FIGS. 15A-15D , the immutableness of the data model is not violated. 
     As described herein, the data analysis system  100  may determine an abridged data analysis graph from the active path. For example, an abridged data analysis graph corresponds to the active path  1516  with only the nodes that correspond to data sets and/or transformations of data sets (e.g., filter, enrich, set math, pivot table, time series, and/or heatmap). In one example, if node  1514  corresponds to a presentation node (e.g., a summary type node, an export node, or a chart node) and the remaining nodes in the active path  1516  correspond to data transformation type and/or data set nodes then the data analysis system would identify the abridged data analysis graph as nodes  1502 ,  1510 ,  1512 , and  1508 C. 
     With respect to  FIG. 15E , the data environment  1520  includes an example data analysis graph  1501 E. The example data analysis graph  1501 E may be similar to the example data analysis graph  1501 A of  FIG. 15A . For example, the example data analysis graph  1501 B corresponds to the same data analysis graph  1501 A but at another second time (such as T=1′). Continuing with the example, a user may want to “insert” a new node into the data analysis graph  1501 A between nodes  1502  and  1504 A. Accordingly, since the nodes are immutable, the data analysis system  100  generates a new node  1518  and duplicates the nodes after the insertion point (here nodes  1504 A,  1506 A,  1508 A are duplicated as nodes  1504 B,  1506 B, and  1508 B, respectively). The data analysis system  100  provides the illusion of an “insertion” by connecting the new node  1518  to the first node before the “insertion” (here root node  1502 ) and to the first duplicated node (here node  1504 B). Again, in the example corresponding to  FIGS. 15A and 15E , the immutableness of the data model is not violated. 
     There may be technical advantages to the systems and methods for graph manipulation as described herein. For example, the use of graphs and nodes for data analysis may enable efficient addition to existing data structures without endangering current functionality. The existing data structures and schemas for the graph models described herein can be highly flexible. For example, new node types and relationships can be added to existing graph data structures. 
     Example User Interface and Data Analysis Processes 
       FIG. 16  includes a flowchart of an example method  1600  for “refreshing” and/or “modifying” a data analysis graph, according to some embodiments of the present disclosure. Although the method  1600  is described in conjunction with the systems of  FIG. 6 , any system configured to perform the method, in any order, is within the scope of this disclosure. The method  1600  may be performed by the data analysis system  100  of  FIG. 6 . Depending on the embodiment, the method  1600  may include fewer or additional blocks and/or the blocks may be performed in an order different than is illustrated. 
     At block  1602 , the data analysis system  100  retrieves a first data analysis graph. An example first data analysis graph corresponds to the data analysis graph  1501 A of  FIG. 15A . In some embodiments, the data analysis system  100  retrieves the first data analysis graph from the data source  170 . Portions of additional example data analysis graphs are presented in the user interfaces of  FIGS. 7 and/or 10 . Accordingly, the example method  1600  to “modify” and/or “refresh” a data analysis graph may be initiated by a user via the user interfaces of  FIGS. 7 and/or 10 , for example. In the “refresh” example, the user selects the “refresh” control  1016  of  FIG. 10  to initiate a data refresh for the node  1014  within the data analysis graph shown within the first presentation area  1002 . As described herein, the first data analysis graph may include one or more nodes. 
     In some embodiments, the data analysis system  100  receives a request to update and/or modify a data analysis graph. In some embodiments of the refresh example, a user may select a refresh control that transmits a refresh request to the data analysis system  100 , and the refresh request may include data that indicates the data analysis graph and/or node to be refreshed. In other embodiments, the data analysis system  100  automatically refreshes the data node, which might be triggered by a determined update to the data source associated with the data node. In some embodiments of the modification example, a user, via a user interface, may select user interface options to insert and/or delete a node from a data analysis graph. An example modification request is a node insertion request. In some embodiments, the data analysis system  100  receives a node insertion request via the user interface, such as the user interface  700  of  FIG. 7 . In the  FIG. 7  example, a user may specify to insert a node between two existing nodes of the data analysis graph. Accordingly, the example node insertion request includes data that corresponds to a node insertion point. In the example of  FIG. 15E , an example insertion point is between nodes  1502  and  1504 A. 
     In some embodiments, the data analysis system  100  determines and/or receives notifications that there has been an update to a data source that corresponds to the data set for a particular node in a data analysis graph. In some embodiments, the data analysis system  100  monitors the data sources  172  for updates to data. In other embodiments, the data analysis system  100  receives notifications from a notification service associated with the data sources  172  when there has been an update to data. In some embodiments, a node may include metadata that indicates the data source for its data set, such that when the data analysis system  100  determines and/or receives notifications that there has been an update to the data source, the data analysis system  100  may determine the corresponding affected nodes by identifying nodes that sourced data from the updated data source. As described herein, the example data analysis system  100  presents a notification to a user when there has been an update to the data source of a node and/or a node has stale data. 
     At block  1604 , the data analysis system  100  identifies an active path of the first data analysis graph. The example active path corresponds to one or more linked nodes in the first data analysis graph that represent a user&#39;s selected traversal through the graph that is being presented within the user interface. An example active path is the active path  1516  of  FIG. 15D . In some embodiments, the data analysis system  100  stores historical user interaction data, such as breadcrumb data, for each user selection of a node in a graph, which the data analysis system  100  can later access to identify the active path. For example, in the example of  FIG. 15D , the data analysis system  100  stores data that indicates the user has selected nodes  1502 ,  1510 ,  1512 ,  1508 C, and  1514  for presentation. 
     In some embodiments, the data analysis system  100  stores historical user interaction data that includes a current node. An example current node is a leaf node in a data analysis graph. In the example of  FIG. 15B , the current node is the node  1508 B. The example data analysis system  100  identifies the current node from the historical user interaction data based on metadata identifying a node as the currently selected node in a particular traversal of the data analysis graph. The example data analysis system  100  further identifies the active path as one or more nodes based on a dependency of the current node. Continuing with the example of  FIG. 15B , the current node  1508 B has dependencies on nodes  1506 B,  1510 , and  1502 , which may be determined based on the links (which can be directed) between nodes  1508 B,  1506 B,  1510 , and  1502 . Accordingly, in the example of  FIG. 15B , the data analysis system  100  identifies the active path as nodes  1502 ,  1510 ,  1506 B, and  1508 B. As another example, in  FIG. 15D , the current node is node  1514 , which has dependencies on nodes  1508 C,  1512 ,  1510 , and  1502 , and the data analysis system  100  identifies the active path as nodes  1502 ,  1510 ,  1512 ,  1508 C, and  1514 . 
     At block  1606 , the data analysis system  100  generates one or more duplicate nodes. The data analysis system  100  determines which nodes to duplicate based on the active path. In some embodiments of the node configuration update example, the data analysis system  100  identifies the data node to be refreshed. Continuing with the example, the data analysis system  100  duplicates one or more nodes from the first data analysis graph that follow the identified data node. In the example of  FIGS. 15A and 15B , the data analysis system  100  identifies node  1504 A to be refreshed. Accordingly, in the example, the data analysis system  100  duplicates nodes  1506 A and  1508 A as new nodes  1506 B and  1508 B, respectively, because the nodes  1506 A and  1508 A follow the identified node  1504 A. 
     In some embodiments of the data insertion example (sometimes referred to herein as “modifying a data analysis graph”), the data analysis system  100  identifies the data node that precedes the insertion point. In some embodiments of the example of  FIGS. 15A and 15E , the node insertion point within the data analysis graph  1501 A is between nodes  1502  and  1504 A. Accordingly, the node that precedes the insertion point is node  1502 . Continuing with the example, the data analysis system  100  duplicates  1504 A,  1506 A, and  1508 A as new nodes  1504 B,  1506 B, and  1508 B, respectively, because the nodes  1506 A,  1506 A, and  1508 A follow the identified node  1502 . 
     At block  1608 , the data analysis system  100  generates a second node. In the node configuration update example, the generated second node corresponds to a modified first data node. In the example of  FIGS. 15A and 15B , the data analysis system  100  generates a modified first data node  1510  based on the configuration change that corresponds to user actions through the user interface. In the data insertion example, the generated second node corresponds to a new node that may be different than a new node in the node configuration update example. 
     At block  1610 , the data analysis system  100  generates a second data analysis graph. In some embodiments, the data analysis system  100  generates the second data analysis graph from the duplicate nodes and the generated second node. In some embodiments, the data analysis system  100  connects the generated second node and the duplicate nodes to generate the second data analysis graph. Depending on the embodiment, the first and second data analysis graphs may or may not be connected and/or linked together. 
     In some embodiments, the data analysis system  100  connects the first data analysis graph and the second data analysis graph. In the node configuration update example, the data analysis system  100  identifies the parent node of the data node that was refreshed (e.g., the data node that precedes the data node that was refreshed). In the example of  FIGS. 15A and 15B , the data analysis system  100  identified node  1502  as the parent node of the updated first data node  1510  (also referred to herein as the “generated second node”). Accordingly, the data analysis system  100  generates a link between the parent node and the updated first data node. In some embodiments, the active path of the data analysis graph, which is described herein, can be copied standalone. Accordingly, in the example of  FIGS. 15A and 15B , the data analysis system  100  generates a link between the identified node  1502  and the updated first data node  1510 , which is further connected to the duplicate nodes  1506 B and  1508 B. In the example of  FIG. 15B , the first and second data analysis graphs are connected together. 
     Continuing with the example, the first data analysis graph includes the first data node and two or more additional nodes that are linked according to a first order. In the example of  FIGS. 15A and 15B , the node  1502  is the first data node, and the nodes  1504 A,  1506 A, and  1508 A are linked in that order. Continuing with the example, the data analysis system  100  generates a first link between the updated first node and a duplicate node. Further, the example data analysis system  100  generates a second link between the duplicate nodes (which includes at least two nodes) according to the first order. In the example of  FIGS. 15A and 15B , the data analysis system  100  generates a link between the duplicate nodes  1506 B and  1508 B according to the order of the corresponding nodes  1506 A and  1508 A. 
     In the data insertion example, the data analysis system  100  identified the data node that preceded the insertion point. The example data analysis system  100  links the identified node to the generated second node as indicated by the insertion point, and links the generated second node to a duplicate node as indicated by the insertion point. In the example of  FIGS. 15A and 15E , the data analysis system  100  identified node  1502  as the node that preceded the insertion point. Accordingly, in the example of  FIGS. 15A and 15E , the data analysis system  100  links the identified node  1502  to the generated second node  1518  as indicated by the insertion point, and links the generated second node  1518  to the duplicate node  1504 B as indicated by the insertion point. In some embodiments, the data analysis system  100  further connects the remaining duplicate nodes. In the example of  FIG. 15E , the data analysis system  100  links the duplicate nodes  1504 B,  1506 B, and  1508 B according to a determined order, as described herein. In the example of  FIG. 15E , the first and second data analysis graphs are connected together (and in some embodiments the first and second data analysis graphs may share one or more common nodes). 
       FIG. 16  includes a flowchart of an example method  1620  for generating and/or identifying an abridged data analysis graph, according to some embodiments of the present disclosure. Although the method  1620  is described in conjunction with the systems of  FIG. 6 , any system configured to perform the method, in any order, is within the scope of this disclosure. The method  1620  may be performed by the data analysis system  100  of  FIG. 6 . Depending on the embodiment, the method  1620  may include fewer or additional blocks and/or the blocks may be performed in an order different than is illustrated. 
     At block  1622 , the data analysis system  100  retrieves a data analysis graph. The block  1622  may be similar to the block  1602  of the example method  1600 . In some embodiments, the data analysis system  100  retrieves the data analysis graph from the data source  170 . Portions of an example data analysis graph are presented in the user interface  700  of  FIG. 7 . Accordingly, the example method  1620  to generate an abridged data analysis graph may be initiated by a user via the user interface  700  of  FIG. 7 . Continuing with the example, the user selects the view control  704  of  FIG. 7  to initiate generation and/or identification of the abridged data analysis graph. 
     At block  1624 , the data analysis system  100  identifies an active path of the data analysis graph. Block  1624  may be similar to the block  1604  of the example method  1600 . 
     At block  1626 , the data analysis system  100  identifies non-transformation node(s) from the active path. In some embodiments, the data analysis system  100  may identify non-transformation nodes based on a predetermined list of node types that do not perform transformations (such as a list including an export node type and a chart node type, for example). In the example, the data analysis system  100  identifies a non-transformation node by determining a node type from a node in the active path. Example node types include a summary node type, a table node type, a histogram node type, a distribution node type, a time series node type, a grid node type, a heatmap node type, a pivot table node type, a filter node type, a column editor node type, an enrich node type, a link node type, a set math node type, an export node type, and/or a chart node type. An example list of non-transformation node types includes an export node type and a chart node type, and, in some embodiments, the remaining example node types may correspond to transformation node types. Additionally or alternatively, the data analysis system  100  may dynamically analyze the nodes in active path determine whether the node includes a transformation operation. In the example of  FIG. 15D , the data analysis system  100  identifies that the node  1514  is a non-transformation node (and not a data set node), such as an export node or a chart node. 
     At block  1628 , the data analysis system  100  identifies the abridged data analysis graph from the active path and the identified non-transformation node(s). In some embodiments, the data analysis system  100  identifies the abridged data analysis graph by omitting the identified non-transformation node(s) from the set of nodes in the active path. In the example of  FIG. 15D , the active path  1516  includes nodes  1502 ,  1510 ,  1512 ,  1508 C, and  1514 . Accordingly, the data analysis system  100  identifies the abridged data analysis graph as nodes  1502 ,  1510 ,  1512 , and  1508 C by omitting the non-transformation node  1514  from the set of nodes in the active path  1516 . The data analysis system  100  may present the identified an abridged data analysis graph. An example presentation of an abridged data analysis graph is described in further detail with respect to  FIGS. 8 and 9 . 
       FIG. 16  includes a flowchart of an example method  1630  of generating one or more user interfaces and/or nodes, according to some embodiments of the present disclosure. Although the method  1630  is described in conjunction with the systems of  FIG. 6 , any system configured to perform the method, in any order, is within the scope of this disclosure. The method  1630  may be performed by the data analysis system  100  of  FIG. 6 . Depending on the embodiment, the method  1630  may include fewer or additional blocks and/or the blocks may be performed in an order different than is illustrated. In some embodiments, the example method  1630  may correspond to the user interfaces of  FIGS. 11-14 . 
     At block  1632 , the data analysis system  100  retrieves a data analysis graph. The block  1632  may be similar to the block  1602  and/or the block  1622  of the example methods  1600  and/or  1620 , respectively. 
     At block  1634 , the data analysis system  100  causes presentation of one or more nodes. In the example user interface that enables a user to edit a data set, the data set associated with the node is presented, which is described in further detail with respect to  FIG. 11 . In the example report user interface, report user interfaces are presented with respect to one or more nodes, which is described in further detail with respect to  FIG. 12 . In the example enrich node user interface, data associated with the enrich node is presented, which is described in further detail with respect to  FIG. 13 . In the example chart node user interface, data associated with the chart node is presented, which is described in further detail with respect to  FIG. 14 . 
     At block  1636 , the data analysis system  100  receives user interaction data. In the data editing example, example user interaction data includes one or more selected function operations and/or new data values. Example function operations on a data set include an undo function, a redo function, a filter function, a find and replace function, an obfuscate function, a mask function, a parse dates function, a remove characters function, a combine column function, a remove column function, a rename column function, a split column function, and/or other spreadsheet functions, as described herein in further detail with respect to  FIG. 11 . Example new data values may be received via the user interface  1100  of  FIG. 11 , as described herein. 
     In some embodiments, the user interaction data includes data corresponding to an expression language. An example data analysis system  100  enables a user to use an expression language to modify data in a data set. For example, a user may specify some two or more columns in an expression language. In another example, a user may specify conditional logic in the expression language, such as if a cell value equals value X, then perform some function. In some embodiments, expression language input may be received via the user interface  1100  of  FIG. 11 . The example data analysis system  100  receives expression language data via user input. For example, the expression language may data may include user input, such as the textual data “SUM(ColumnA, ColumnB)”. Accordingly, the expression language may include a set of defined functions that can be selected and/or entered by a user in an expression language and be dynamically applied to the data set of a node to generate a new data set and/or new data values. Other example functions include count, count non-empty cells, count the number of characters in a cell, remove whitespace in a cell, lookup a value of a cell, if/then statements, average, and/or some combination thereof. 
     In the example report user interface, example user interaction data includes text data input and/or chart configuration data. For example, a user may specify textual and/or other input data to be presented within the report user interface. In another example, a user may further configure one or more charts in the report user interface. Additional details regarding user interaction data and report user interfaces are described in further detail with respect to  FIG. 12 . 
     In the example enrich node user interface, example user interaction data includes user input regarding join operations. Example user input includes the type of join operation, the data sets that are to be joined, column prefixes, and/or column selections. Additional details regarding user interaction data and report user interfaces are described in further detail with respect to  FIG. 13 . 
     In the example chart node user interface, example user interaction data includes user input regarding one or more charts. Example user input includes the type of chart, chart styles, one or more axes of the chart, and/or group by conditions. Additional details regarding user interaction data and chart node user interfaces are described in further detail with respect to  FIG. 14 . 
     At block  1638 , the data analysis system  100  processes the user interaction data. In some embodiments, the data analysis system  100  generates new data nodes, as described herein, to store the received user interaction data. Additionally or alternatively, the data analysis system  100  further connects the new data nodes data analysis graph. Accordingly, the block  1638  may be similar to blocks  1604 ,  1606 ,  1608 , and/or  1610  of the example method  1600 . As illustrated, the data analysis system  100  may further present the new data nodes at block  1634 . 
     In the data editing example, the data analysis system  100  applies the user interaction data, which includes the one or more selected function operations and/or the new data values, to the current data set to generate a new data set and/or node. In the reporting example, the data analysis system  100  stores the user interaction data, which includes text data input and/or chart configuration data, in a new node. Continuing with the reporting example, the data analysis system  100  presents an updated report user interface based on the data from the new node. In the example enrich node example, the data analysis system  100  applies the user interaction data, which includes user input regarding join operations, to the current data set and to the other data set to generate a new data set and/or node by executing the join operation. Continuing with the enrichment example, the data analysis system  100  presents an updated enrich node based on the data from the new data set and/or node. In the chart node example, the data analysis system  100  stores the user interaction data, which includes user input regarding one or more charts, in a new node. Continuing with the chart example, the data analysis system  100  generates and/or presents a new chart with the stored user interaction data from the new node. 
     As described herein, the example method  1630  may be applied in a variety of contexts such as the data editing example, the reporting example, the enrichment example, and/or the chart example. 
     In the data editing example, the data analysis system  100  retrieves a data analysis graph; causes presentation of one or more nodes; receives user input including new data values, expression language input, new column information, and/or function configuration data; generates a new node based on the user input; stores the new node; causes presentation of the new node; and/or some combination thereof. Continuing with the example, the data analysis system  100  generates a new node by updating the data in the data set according to the user input, such as by inserting new data values and/or overwriting existing data values, applying functions to the data set, applying expression language input to the data set, and/or modifying the column data in the data set. 
     In the reporting example, the data analysis system  100  retrieves a data analysis graph; causes presentation of one or more nodes; receives report configuration data for one or more nodes; accesses a data set from a node in the data analysis graph; accesses report configuration data associated with the node; generates a report in the user interface, where the report includes data from the data set, based at least in part on the report configuration data; and/or some combination thereof. Continuing with the example, the report configuration data indicates the type of report, chart configuration data, which data values from the data set to access, and/or instructions to generate the chart and/or report from the data values. 
     In the enrichment example, the data analysis system  100  retrieves a data analysis graph; causes presentation of one or more nodes in the data analysis graph; receives enrichment and/or join configuration data; joins a first data set and a second data set to determine a third data set; stores the third data set as a node in a data analysis graph; and/or some combination thereof. 
     In the chart example, the data analysis system  100  retrieves a data analysis graph; causes presentation of one or more nodes in the data analysis graph; receives chart configuration data for the node; accesses a data set from the node in the data analysis graph; accesses chart configuration data associated with the node; generates a chart in the user interface, where the chart includes data from the data set, based at least in part on the report configuration data; and/or some combination thereof. Continuing with the example, the chart configuration data indicates the type of chart, other chart configuration data, x and y-axes, what functions (such as group by) to apply, which data values from the data set to access, and/or instructions to generate the chart from the data values. 
     While some advantages of the systems and methods described herein are discussed in the context of immutability, some embodiments of the present disclosure may also be used and/or advantageous in the context of data objects with mutable properties. For example, in editing a data node, the property values of the data node may be changed instead of generating a new data node.