Patent Publication Number: US-2023147197-A1

Title: Editing and updating database tables on a cloud-based data warehouse

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a non-provisional application for patent entitled to a filing date and claiming the benefit of earlier-filed U.S. Provisional Patent Application Ser. No. 63/278,356, filed Nov. 11, 2021, the contents of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND 
     Field of the Invention 
     The field of the invention is data processing, or, more specifically, methods, apparatus, and products for editing and updating database tables on a cloud-based data warehouse. 
     Description of Related Art 
     Modern businesses may store large amounts of data in remote databases within cloud-based data warehouses. This data may be accessed using database statement languages, such as structured query language (SQL). Manipulating the data stored in the database may require constructing complex queries beyond the abilities of most users. Further, composing and issuing database queries efficiently may also be beyond the abilities of most users. 
     SUMMARY 
     Methods, systems, and apparatus for editing and updating database tables on a cloud-based data warehouse including receiving, by a table manager via a client computing system, an instruction to edit a modified base table on the cloud-based data warehouse, wherein the instruction comprises a table edit targeting the modified base table; locating, by the table manager, a modifications table on the cloud-based data warehouse associated with the modified base table, wherein the modified base table comprises a base table and the modifications table; and servicing the instruction to edit the modified base table by generating a database statement targeting the cloud-based data warehouse to apply the table edit to the modifications table associated with the modified base table. 
     The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular descriptions of exemplary embodiments of the invention as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts of exemplary embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    sets forth a block diagram of an example system configured for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention. 
         FIG.  2    sets forth a block diagram of an example system configured for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention. 
         FIG.  3    sets forth a block diagram of an example system configured for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention. 
         FIG.  4    sets forth a flow chart illustrating an exemplary method for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention. 
         FIG.  5    sets forth a flow chart illustrating an exemplary method for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary methods, apparatus, and products for editing and updating database tables on a cloud-based data warehouse in accordance with the present invention are described with reference to the accompanying drawings, beginning with  FIG.  1   .  FIG.  1    sets forth a block diagram of automated computing machinery comprising an exemplary intermediary computing system  152  configured for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention. The intermediary computing system  152  of  FIG.  1    includes at least one computer processor  156  or ‘CPU’ as well as random access memory  168  (RAM′) which is connected through a high speed memory bus  166  and bus adapter  158  to processor  156  and to other components of the intermediary computing system  152 . 
     Stored in RAM  168  is an operating system  154 . Operating systems useful in computers configured for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention include UNIX™, Linux™, Microsoft Windows™, AIX™, and others as will occur to those of skill in the art. The operating system  154  in the example of  FIG.  1    is shown in RAM  168 , but many components of such software typically are stored in non-volatile memory also, such as, for example, on data storage  170 , such as a disk drive. Also stored in RAM is the table manager  126 , a module for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention. 
     The intermediary computing system  152  of  FIG.  1    includes disk drive adapter  172  coupled through expansion bus  160  and bus adapter  158  to processor  156  and other components of the intermediary computing system  152 . Disk drive adapter  172  connects non-volatile data storage to the intermediary computing system  152  in the form of data storage  170 . Disk drive adapters useful in computers configured for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention include Integrated Drive Electronics (‘IDE’) adapters, Small Computer System Interface (‘SCSI’) adapters, and others as will occur to those of skill in the art. Non-volatile computer memory also may be implemented for as an optical disk drive, electrically erasable programmable read-only memory (so-called ‘EEPROM’ or ‘Flash’ memory), RAM drives, and so on, as will occur to those of skill in the art. 
     The example intermediary computing system  152  of  FIG.  1    includes one or more input/output (‘I/O’) adapters  178 . I/O adapters implement user-oriented input/output through, for example, software drivers and computer hardware for controlling output to display devices such as computer display screens, as well as user input from user input devices  181  such as keyboards and mice. The example intermediary computing system  152  of  FIG.  1    includes a video adapter  209 , which is an example of an I/O adapter specially designed for graphic output to a display device  180  such as a display screen or computer monitor. Video adapter  209  is connected to processor  156  through a high speed video bus  164 , bus adapter  158 , and the front side bus  162 , which is also a high speed bus. 
     The exemplary intermediary computing system  152  of  FIG.  1    includes a communications adapter  167  for data communications with other computers and for data communications with a data communications network. Such data communications may be carried out serially through RS-232 connections, through external buses such as a Universal Serial Bus (‘USB’), through data communications networks such as IP data communications networks, and in other ways as will occur to those of skill in the art. Communications adapters implement the hardware level of data communications through which one computer sends data communications to another computer, directly or through a data communications network. Examples of communications adapters useful in computers configured for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention include modems for wired dial-up communications, Ethernet (IEEE 802.3) adapters for wired data communications, and 802.11 adapters for wireless data communications. 
     The communications adapter  167  is communicatively coupled to a wide area network  190  that also includes a cloud-based data warehouse  192  and a client computing system  194 . The cloud-based data warehouse  192  is a computing system or group of computing systems that hosts a database or databases for access over the wide area network  190 . The client computing system  194  is a computing system that accesses the database using the table manager  126 . 
       FIG.  2    shows an exemplary system for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention. As shown in  FIG.  2   , the system includes a client computing system  194 , an intermediary computing system  152 , and a cloud-based data warehouse  192 . The client computing system  194  includes a graphical user interface (GUI)  202 . The intermediary computing system  152  includes a table manager  126  and an edit queue  206 . The cloud-based data warehouse  192  includes a database  204 . The client computing system  194  may access the cloud-based data warehouse  192  and database  204  via the table manager on the intermediary computing system  152 . 
     The GUI  202  is a visual presentation configured to present data sets in the form of worksheets, workbooks, and graphical elements to a user. The GUI  202  also receives requests from a user for data sets from the database  204 . The GUI  202  may also present to the user the ability to add a new row into a data set or table and enter values for each column of the new row. The GUI  202  may be presented, in part, by the table manager  126  and displayed on a client computing system  194  (e.g., on a system display or mobile touchscreen). The GUI  202  may be part of an Internet application that includes the table manager  126  and is hosted on the intermediary computing system  152 . 
     The database  204  is a collection of data and a management system for the data. A data set is a collection of data (such as a table) from the database  204 . Data sets may be organized into columns and rows (also referred to as records). The particular columns, rows, and organization of the columns and rows that make up a data set may be specified in the database statement requesting the data set. Data sets may be sent from the cloud-based data warehouse  192  in response to a database statement (also referred to as a query). Accordingly, data sets retrieved in response to a database statement may be referred to as query results. The database may store the data sets that make up a base table and a modifications table. 
     The table manager  126  is hardware, software, or an aggregation of hardware and software configured to receive instructions in the form of state specifications from the client computing system  194 , via the GUI  202 . The table manager  126  is also configured to generate database statements in response to manipulations of the GUI  202  described in the state specification. 
     The state specification is a collection of data describing inputs into the GUI  202 . The state specification may include manipulations of GUI elements within the GUI  202  along with data entered into the GUI  202  by a user of the client computing system  194 . Such manipulations and data may indicate requests for and manipulations of data sets. Such manipulations and data may also indicate requests to edit an existing row or create a new row and values for that row. The state specification may be a standard file format used to exchange data in asynchronous browser-server communication. For example, the state specification may be a JavaScript Object Notation specification. The state specification may also include descriptions of elements that are used to apply changes to the data set. Such elements may include filters applied to the worksheet, the hierarchical level of the worksheet, joins performed within the worksheet, exposable parameters in the worksheet, and security for the worksheet. 
     The table manager  126  uses the state specification as input to generate a database statement. This database statement generation process may begin with state specification being converted into an abstract syntax tree. The abstract syntax tree may then be canonicalized into a canonicalized hierarchy. The canonicalized hierarchy may then be linearized into the worksheet algebra. The worksheet algebra may then be lowered into a relational algebra, which may then be lowered into the database statement. 
     The table manager  126  may use the database statement to fetch query results (i.e. a data set) from the database  204 . The table manager  126  may then present the query results to a user via the GUI  202 . The table manager  126  may further manage tables on the database  202  to which a user has made edits, such as adding new rows or editing existing rows. Further, the table manager  126  may add columns to new rows and create new tables on the database  202 . 
     The edit queue  206  is a repository for uncommitted table edits made to an editable table. A table edit describes the change (e.g., add row, edit row, remove row, etc.) to be made to a table (e.g., a modifications table). Table edits in the edit queue  206  are sent to the database  204  on the cloud-based data warehouse  192  to be committed to the editable table. “Committed” as used herein refers to a table edit to the editable table that has been accepted by the database  204  on the cloud-based data warehouse  192  and is currently reflected in query results from the database  204 . Similarly, “uncommitted” as used herein refers to any table edit that is not currently reflected in query results from the database  204 . Note that a table edit is still reflected in query results even if that table edit has been deleted or overwritten by a later table edit. 
     Table edits may be sent individually or in batches to the database  204  on the cloud-based data warehouse  192 . Further, table edits stored in the edit queue  206  may be stored as database statements (e.g., as structured query language statements). Alternatively, the table edits may be stored in an intermediate representation before being converted to a database statement and transmitted. Each uncommitted table edit may be held in the edit queue  206  until a commitment acknowledgement for the uncommitted table edit is received from the cloud-based data warehouse  192 . The edit queue  206  may also include a mechanism to service requests from the table manager  126 . Specifically, the edit queue  206  may include the ability to respond to requests from the table manager  126  and provide rows from the uncommitted edits in response. 
       FIG.  3    shows an exemplary system for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention. As shown in  FIG.  3   , the exemplary GUI  202  includes a spreadsheet structure  302  and a list structure  304 . The spreadsheet structure  302  includes a worksheet (shown as empty rows) with six columns (column A  306 A, column B  306 B, column C  306 C, column D  306 D, column E  306 E, column F  306 F). The combination of a worksheet and dynamic graphic elements may be referred to as a workbook. 
     The spreadsheet structure  302  is a graphical element and organizing mechanism for a worksheet that presents a data set. A worksheet is a presentation of a data set (such as a table) from a database on a data warehouse. The spreadsheet structure  302  displays the worksheet as rows of data organized by columns (column A  306 A, column B  306 B, column C  306 C, column D  306 D, column E  306 E, column F  306 F). The columns delineate different categories of the data in each row of the worksheet. The columns may also be calculation columns that include calculation results using other columns in the worksheet. 
     The list structure  304  is a graphical element used to define and organize the hierarchical relationships between the columns (column A  306 A, column B  306 B, column C  306 C, column D  306 D, column E  306 E, column F  306 F) of the data set. The term “hierarchical relationship” refers to subordinate and superior groupings of columns. For example, a database may include rows for an address book, and columns for state, county, city, and street. A data set from the database may be grouped first by state, then by county, and then by city. Accordingly, the state column would be at the highest level in the hierarchical relationship, the county column would be in the second level in the hierarchical relationship, and the city column would be at the lowest level in the hierarchical relationship. 
     The list structure  304  presents a dimensional hierarchy to the user. Specifically, the list structure  304  presents levels arranged hierarchically across at least one dimension. Each level within the list structure  304  is a position within a hierarchical relationship between columns (column A  306 A, column B  306 B, column C  306 C, column D  306 D, column E  306 E, column F  306 F). The keys within the list structure  304  identify the one or more columns that are the participants in the hierarchical relationship. Each level may have more than one key. 
     One of the levels in the list structure  304  may be a base level. Columns selected for the base level provide data at the finest granularity. One of the levels in the list structure  304  may be a totals or root level. Columns selected for the totals level provide data at the highest granular level. For example, the totals level may include a field that calculates the sum of each row within a single column of the entire data set (i.e., not partitioned by any other column). 
     The GUI  202  may enable a user to drag and drop columns (column A  306 A, column B  306 B, column C  306 C, column D  306 D, column E  306 E, column F  306 F) into the list structure  304 . The order of the list structure  304  may specify the hierarchy of the columns relative to one another. A user may be able to drag and drop the columns in the list structure  304  at any time to redefine the hierarchical relationship between columns. The hierarchical relationship defined using the columns selected as keys in the list structure  304  may be utilized in charts such that drilling down (e.g., double click on a bar), enables a new chart to be generated based on a level lower in the hierarchy. 
     The GUI  202  may also include a mechanism for a user to request a table from a database to be presented as a worksheet in the GUI  202 . Such a mechanism may be part of the interactivity of the worksheet. Specifically, a user may manipulate a worksheet (e.g., by dragging and dropping columns or rows, resorting columns or rows, etc.) and, in response, the GUI  202  may generate a request (e.g., in the form of a state specification) for a data set and send the request to the table manager  126 . Such a mechanism may also include a direct identification of the rows and columns of a database table that a user would like to access (e.g., via a selection of the rows and columns in a dialog box). The GUI  202  may also include a mechanism for a user to create a new table on the database, add rows to a table, and move rows within the table. 
     For further explanation,  FIG.  4    sets forth a flow chart illustrating an exemplary method for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention that includes receiving  402 , by a table manager  126  via a client computing system, an instruction  420  to edit a modified base table on the cloud-based data warehouse  192 , wherein the instruction  420  comprises a table edit targeting the modified base table. Receiving  402  the instruction  420  to edit a modified base table on the cloud-based data warehouse  192  may be carried out by detecting that a user has manipulated elements of the GUI and/or submitted data using the GUI such that the generation of the instruction  420  is triggered, and the instruction  420  is sent to the table manager  126 . 
     The instruction  420  may be received in the form of a state specification from the GUI. Specifically, each change to the GUI may result in a new or updated state specification  420  that operates as an instruction to the table manager  126 . The initial presentation of the modified base table may be in response to a table request made through the GUI. For example, a user of the client computing system may select the modified base table from a group of tables presented for display on the GUI. The instruction  420  to edit the modified base table may be received without presenting  402  the modified base table. The table edit is an instruction to change the modified base table. For example, the table edit may be a new row to add to the modified base table. As another example, the table edit may be a change to an existing row in the modified base table. 
     The modified base table is a table stored on a database within the cloud-based data warehouse. The modified base table is a combination of a base table and a modifications table. The modified base table may be used to allow a group of clients to appear to edit a base table but without making any actual edits to the base table on the cloud-based data warehouse. For example, a base table may include data from a particular source and be treated as a source-of-truth dataset. Using a modified base table, the table manager allows a group of clients to manipulate and/or add to the base table without altering the underlying base table. The manipulations and additions to the base table are stored separately in the modifications table (also referred to as a companion table). When one of the group of clients requests the base table, the modified base table is generated by combining the base table with the modifications table and presented to the client. 
     Both the base table and modifications table may exist on the cloud-based data warehouse  192 . Alternatively, the modifications table may reside on another computing system, such as the intermediary computer system. The base table may be a table that the table manager or source of the instruction  420  is restricted from editing. The modifications table may be a table that the table manager or source of the instruction  420  is not restricted from editing. 
     The base table may include (or exclusively include) data stored thereupon by an entity or entities that are separate and distinct from the entity or entities storing data on the modifications table. In other words, the modifications table includes edits made by a first category of clients, and the base table includes edits made by a second category of clients. The first category of client may be clients that access the database on the cloud-based data warehouse using the table manager and the second category of client may be clients that access the database on the cloud-based data warehouse directly and/or without using the table manager. Alternatively, the first category of clients may be a first group of users of the table manager with a first set of permissions (e.g., permission to edit the modifications table) and the second category of clients may be a second group of users of the table manager with a second set of permissions (e.g., permission to edit the base table). 
     The method of  FIG.  4    also includes locating  404 , by the table manager  126 , a modifications table on the cloud-based data warehouse  192  associated with the modified base table, wherein the modified base table comprises a base table and the modifications table. Locating  404  the modifications table on the cloud-based data warehouse  192  may be carried out by searching the cloud-based data warehouse for the modifications table using a modifications table identifier (the identifier may be derived from the instruction  420  or modified base table). Alternatively, the location of the modifications table may be stored with the base table on the cloud-based data warehouse. Finally, locating the modifications table may include accessing a data structure mapping the modified base table to the modifications table. The data structure may be on the cloud-based data warehouse or reside on the intermediary computing system with the table manager. Once the entry for the particular modified base table is retrieved, the address for the modifications table in the entry may be used to locate the modifications table. 
     The method of  FIG.  4    also includes servicing  406  the instruction  420  to edit the modified base table by generating a database statement targeting the cloud-based data warehouse  192  to apply the table edit to the modifications table associated with the modified base table. Generating the database statement to apply the table edit to the modifications table may be carried out by the table manager  126  or query compiler on the intermediary computing system using the table edit to create the database statement. Creating the database statement may include lowering the intermediate representation into the database statement. The database statement may be a structured query language statement. Servicing  406  the instruction  420  to edit the modified base table may further include sending the database statement to the cloud-based data warehouse and receiving a response (i.e., a query result) in response. The response may be an acknowledgement that the edit has been committed to the database. 
     The above limitations improve the operation of the computer system by separating edits to a base table from the base table itself. This is accomplished by making the received edits to a modifications table. The modifications table is subsequently combined with the base table for presentation to a requesting client. 
     For further explanation,  FIG.  5    sets forth a flow chart illustrating a further exemplary method for editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention that includes receiving  402 , by a table manager  126  via a client computing system, an instruction  420  to edit a modified base table on the cloud-based data warehouse  192 , wherein the instruction  420  comprises a table edit targeting the modified base table; locating  404 , by the table manager  126 , a modifications table on the cloud-based data warehouse  192  associated with the modified base table, wherein the modified base table comprises a base table and the modifications table; and servicing  406  the instruction  420  to edit the modified base table by generating a database statement targeting the cloud-based data warehouse  192  to apply the table edit to the modifications table associated with the modified base table. 
     The method of  FIG.  5    differs from the method of  FIG.  4   , however, in that the method of  FIG.  5    further includes receiving  502  a request  422  to present the modified base table on the client computing system  194 . Receiving  502  a request  422  to present the modified base table on the client computing system  194  may be carried out by detecting that a user has manipulated elements of the GUI and/or submitted data using the GUI such that the generation of the request  422  is triggered, and the request  422  is sent to the table manager  126 . The request  422  may be received in the form of a state specification from the GUI. For example, the user of the client computing system may select the modified base table from a group of tables presented for display on the GUI. The request  422  may be targeting the base table and the table manager  126  may instead present the modified base table to the source of the request  422 . Consequently, the entity requesting the base table may be under the impression that they are editing the base table instead of the modified base table. 
     The method of  FIG.  5    also includes retrieving  504 , from the cloud-based data warehouse  192 , query results comprising the base table merged with the modifications table. Retrieving  504  the query results from the cloud-based data warehouse may be carried out by generating a subsequent database statement that joins, merges, unions, or otherwise combines the base table with the modifications table on the cloud-based data warehouse, which in turn provides the resulting modified base table in the query results. The query results may include the modified base table or include the base table and modifications table which are subsequently combined by the table manager  126 . 
     Changes to the base table are subsequently reflected in the query results. Specifically, the base table may be updated by entities with access to the base table. The changes made to the base table are presented in subsequent query results containing the modified base table. Such changes may also affect additions or modifications from the modification table. For example, if the modifications table adds a column with a formula that uses a column from the base table as an input, as the values from the base table column are changed, the results in the formula column within the resulting modified base table are also changed. 
     The method of  FIG.  5    also includes presenting  506 , on the client computing system  194 , the query results comprising the base table merged with the modifications table. Presenting  506  the query results on the client computing system  194  may be carried out by arranging the modified base table to display in the GUI of the client computing system. 
     In view of the explanations set forth above, readers will recognize that the benefits of editing and updating database tables on a cloud-based data warehouse according to embodiments of the present invention include:
         Improving the operation of the computer system by separating edits to a base table from the base table itself, improving and maintaining the security of the base table.   Improving the operation of a computing system by managing modifications to a base table on an intermediary computing system, increasing system ease of use, robustness, and resiliency.       

     Exemplary embodiments of the present invention are described largely in the context of a fully functional computer system for editing and updating database tables on a cloud-based data warehouse. Readers of skill in the art will recognize, however, that the present invention also may be embodied in a computer program product disposed upon computer readable storage media for use with any suitable data processing system. Such computer readable storage media may be any storage medium for machine-readable information, including magnetic media, optical media, or other suitable media. Examples of such media include magnetic disks in hard drives or diskettes, compact disks for optical drives, magnetic tape, and others as will occur to those of skill in the art. Persons skilled in the art will immediately recognize that any computer system having suitable programming means will be capable of executing the steps of the method of the invention as embodied in a computer program product. Persons skilled in the art will recognize also that, although some of the exemplary embodiments described in this specification are oriented to software installed and executing on computer hardware, nevertheless, alternative embodiments implemented as firmware or as hardware are well within the scope of the present invention. 
     The present invention may be a system, a method, and/or a computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention. 
     The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire. 
     Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device. 
     Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention. 
     Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions. 
     These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions. 
     It will be understood from the foregoing description that modifications and changes may be made in various embodiments of the present invention without departing from its true spirit. The descriptions in this specification are for purposes of illustration only and are not to be construed in a limiting sense. The scope of the present invention is limited only by the language of the following claims.