Patent Publication Number: US-2013238677-A1

Title: System, method and computer program product for using a database to access content stored outside of the database

Description:
CLAIM OF PRIORITY 
     This application is a continuation of U.S. application Ser. No. 13/037,240, filed Feb. 28, 2011, which claims the benefit of U.S. Provisional Patent Application No. 61/308,747, filed Feb. 26, 2010; U.S. Provisional Patent Application No. 61/319,782, filed Mar. 31, 2010; and U.S. Provisional Patent Application No. 61/320,194, filed Apr. 1, 2010; the entire contents of which are incorporated herein by reference, 
    
    
     COPYRIGHT NOTICE 
     A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
     FIELD OF THE INVENTION 
     One or more implementations relate generally to accessing content using a database system. 
     BACKGROUND 
     The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions. 
     In conventional database systems, a type of data capable of being stored in such database systems is limited. For example, each field of a database may be configured to store only a particular type of data. In some cases, the particular type of data may be customized for all fields in a column of the database. Unfortunately, conventional database systems have been limited in their ability to store some types of data, such as rich text, files, and images. For example, rich text, files, and images have generally exceeded the allowable size for data being stored in a single field of a database. 
     Accordingly, it is desirable to provide techniques enabling a database system to be utilized to access content stored outside of the database system to improve the usability of the database system. 
     BRIEF SUMMARY 
     In accordance with embodiments, there are provided mechanisms and methods for using a database to access content stored outside of the database. These mechanisms and methods for using a database to access content stored outside of the database can enable embodiments to provide a database system which can be used to access content when the content is incapable of being stored in the database system, or is otherwise not stored in the database system. The ability of embodiments to provide access to such data via the database system can improve the usability of the database system. 
     In an embodiment and by way of example, a method for using a database to access content stored outside of the database is provided. In use, content is received. Additionally, the content is stored in a file server. Further, metadata referencing a location of the content in the file server is stored in a database. Still yet, the content is accessed using the metadata. 
     While one or more implementations and techniques are described with reference to an embodiment in which using a database to access content stored outside of the database is implemented in a system having an application server providing a front end for an on-demand database service capable of supporting multiple tenants, the one or more implementations and techniques are not limited to multi-tenant databases nor deployment on application servers. Embodiments may be practiced using other database architectures, i.e., ORACLE®, DB2® by IBM and the like without departing from the scope of the embodiments claimed. 
     Any of the above embodiments may be used alone or together with one another in any combination. The one or more implementations encompassed within this specification may also include embodiments that are only partially mentioned or alluded to or are not mentioned or alluded to at all in this brief summary or in the abstract. Although various embodiments may have been motivated by various deficiencies with the prior art, which may be discussed or alluded to in one or more places in the specification, the embodiments do not necessarily address any of these deficiencies. In other words, different embodiments may address different deficiencies that may be discussed in the specification. Some embodiments may only partially address some deficiencies or just one deficiency that may be discussed in the specification, and some embodiments may not address any of these deficiencies. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following drawings like reference numbers are used to refer to like elements. Although the following figures depict various examples, the one or more implementations are not limited to the examples depicted in the figures. 
         FIG. 1  illustrates a method for using a database to access content stored outside of the database, in accordance with an embodiment; 
         FIG. 2  illustrates a method for configuring a database to reference content stored in a file system, in accordance with an embodiment; 
         FIG. 3  illustrates tables of a database system configured to reference content stored outside of the database, in accordance with an embodiment; 
         FIG. 4  illustrates a system for using a database to access content stored outside of the database, in accordance with an embodiment; 
         FIGS. 5A-5F  are screen shots illustrating examples of a user interface screen capable of being used to configure a database to reference content stored outside of the database, in accordance with an embodiment; 
         FIG. 6  illustrates a block diagram of an example of an environment wherein an on-demand database service might be used; and 
         FIG. 7  illustrates a block diagram of an embodiment of elements of  FIG. 6  and various possible interconnections between these elements. 
     
    
    
     DETAILED DESCRIPTION 
     General Overview 
     Systems and methods are provided for using a database to access content stored outside of the database. 
     As used herein, the term multi-tenant database system refers to those systems in which various elements of hardware and software of the database system may be shared by one or more customers. For example, a given application server may simultaneously process requests for a great number of customers, and a given database table may store rows for a potentially much greater number of customers. As used herein, the term query plan refers to a set of steps used to access information in a database system. 
     Next, mechanisms and methods for using a database to access content stored outside of the database will be described with reference to example embodiments, 
       FIG. 1  illustrates a method  100  for using a database to access content stored outside of the database, in accordance with an embodiment. As shown in operation  102 , content is received. In the context of the present embodiment, the content may include a file (e.g. an image file or any other type of file), rich text, or any other content which is incapable of being stored in a database or otherwise for which it is undesired that the content be stored in the database. For example, the content may of a size that is larger than an allowable size for fields of the database. 
     In one embodiment, the content may be received by a multi-tenant on-demand database system for storage thereof by the multi-tenant on-demand database system. For example, the content may be received from a tenant of the multi-tenant on-demand database system. Thus, the multi-tenant on-demand database system may receive the content for storage in association with the tenant. 
     In another embodiment, the content may be received using a graphical user interface used for configuring an entity associated with the tenant (e.g. an entity created by the tenant, used by the tenant, etc. via the multi-tenant on-demand database system). Such entity may include a webpage, just by way of example. To this end, the content may be received for being included in the entity. 
     Additionally, as shown in operation  104 , the content is stored in a file server. The file server may include any file system capable of storing the file. For example, the file server may include a device of the multi-tenant on-demand database system. In one embodiment, the file server may be selected from a plurality of file servers, based on the tenant from whom the content is received. For example, a file server associated with a particular partitioning in which the tenant is included may be selected for storing the content. 
     Further, as shown in operation  106 , metadata referencing a location of the content in the file server is stored in a database. In the context of the present description, the database may be separate from the file server. In particular, the database may optionally be the aforementioned database which is incapable of storing the content, or in which it is otherwise undesirable to store the content. 
     In one embodiment, the database may store information associated with the entity (e.g. webpage) in which the content is to be included. For example, the database may store text to be included in the entity, a formatting associated with the entity, etc. Accordingly, the metadata referencing the location of the content in the file server may be stored in the database, instead of storing the content itself in the database. 
     It should be noted that the metadata may be stored in the database in any desired manner for referencing the location of the content. For example, an address in memory of the file server at which the file is stored may be used in the database to reference the location of the content. Such location reference may be stored in a field of a table of the database in which the file would otherwise be stored, as an option. In one embodiment, an identifier of the location of the content may be stored in a reference table of the database. 
     Still yet, as shown in operation  108 , the content is accessed using the metadata. The access may include reading the content, writing to the content (e.g. to modify the content), etc. For example, accessing the content may include retrieving the content for inclusion in the entity (e.g. webpage), such that the entity including the content may be provided to a user requesting the entity. 
     In one embodiment, the content may be accessed by directly accessing the metadata. Just by way of example, in response to a request for the entity or directly for the content, the portion of the database storing the metadata may be directly queried to identify the location of the content Once the location is identified, the content may be accessed using the identified location. 
     In another embodiment, the content may be accessed by indirectly accessing the metadata. As noted above, the metadata referencing the location of the content (i.e. identifier of the location of the content) may be stored in a reference table of the database. Furthermore, the metadata may be stored (e.g. in the reference table) in association with a content identifier (i.e. a unique identifier of the content). 
     Still yet, the content identifier may point to a record of a field data table storing a reference identifier. For example, the content identifier may also be stored in the field data table in association with the reference identifier. Thus, the content identifier from the reference table may point to the content identifier in the field data table. 
     Moreover, the reference identifier may point to a record of an entity table storing the reference identifier. For example the reference identifier may also be stored in the entity table. To this end, the reference identifier in the field data table may point to the reference identifier in the entity table. Such entity table may store the above described information associated with the entity including the content, in one embodiment. 
     To this end, the reference identifier may be stored in a field of a record of the entity table, for referencing the content. Such field may optionally be configured to store a type of the content, in one embodiment According to the above described schema of tables, access to the content may be provided through the entity table, the field data table, and the reference table. For example, the reference identifier may be identified in the entity table, which may point to a record of the field data table for identifying an associated content identifier, which may further point to a record of the reference table for identifying the identifier of the location of the content. 
     Once the identifier of the location of the content is determined, such identifier may be used to access the content from the file server. In this way, the database may be used to identify the content, without the database necessarily storing the content. 
     More illustrative information will now be set forth regarding various optional architectures and features with which the foregoing technique may or may not be implemented, per the desires of the user. It should be strongly noted that the following information is set forth for illustrative purposes and should not be construed as limiting in any manner. Any of the following features may be optionally incorporated with or without the exclusion of other features described. 
       FIG. 2  illustrates a method  200  for configuring a database to reference content stored in a the system, in accordance with an embodiment. As an option, the present method  200  may be carried out in the context of the functionality of  FIG. 1 . For example, the method  200  may be carried out by the multi-tenant on-demand database system described herein. Of course, however, the method  200  may be carried out in any desired environment. Again, the aforementioned definitions may apply during the present description. 
     As shown in decision  202 , it is determined whether content associated with an entity is received. For example, it may be determined whether content has been uploaded by a tenant of a multi-tenant on-demand database system (e.g. using a GUI of the multi-tenant on-demand database system). As another example, it may be determined whether content has been saved by the tenant to the multi-tenant on-demand database system (e.g. for storage by the multi-tenant on-demand database system). 
     In the context of the present embodiment, the content may include any content which is to be associated with an entity (e.g. of the tenant). For example, the content may be received by the tenant for use in configuring the entity (e.g. a webpage). Accordingly, the content may include text, an image, etc. 
     If it is determined that content has not been received, the method  200  continues to wait for such content to be received. However, once it is determined that content has been received, it is further determined whether a type of the content is supported by an entity table. Note decision  204 . The entity table may include a table of a database storing information for configuring at least one entity. 
     In one embodiment, the entity table may be incapable of storing (i.e. may not necessarily support) content of particular types, such as rich text, a file, an image, content greater than a predetermined length (e.g. 255 characters), etc. Thus, determining whether a type of the content is supported by an entity table may include determining whether the content is one of the unsupported types. If it is determined that the content type is supported by the entity table, the content is stored in the entity table, as shown in operation  206 . For example, the content may be stored in a record specific to the entity with which the content is associated (i.e. a record having an identifier of the entity). Further, the content may be stored in a field of such record that is configured (e.g. by an administrator, etc.) to store the type of the content. 
     As an option, the field may be automatically filtered for at least potentially malicious content. For example, if potentially malicious content is identified, then the potentially malicious content should be automatically removed or transformed into a non-malicious format (e.g. text) for users who view the field. The content may be determined to be potentially malicious if the content includes hypertext transfer markup language (HTML) tags that are not supported by the database (i.e. are not whitelisted), cascading style sheets (CSS), contents of &lt;script&gt; and &lt;iframe&gt; tags, javaScript, etc. 
     If it is determined that the content type is not supported by the entity table, the content is stored in a file system. Note operation  208 . Such file system may include any system that is separate from the database and that is capable of storing the content. As an option, the file system may store content for a plurality of different tenants of the multi-tenant on-demand database system. As another option, the file system may store content for only a subset of all tenants of the multi-tenant on-demand database system (e.g. whether other file systems store content for the remaining tenants, such that the tenants are partitioned across multiple file systems). 
     In one embodiment, the content may be stored in the file server in response to a determination that the content does not include malicious content. For example, the content may be analyzed to ensure that the content does not include JavaScript (which is capable of being malicious), prior to storing the content in the file server. Of course, any security mechanism may be utilized to ensure that content being stored in the file system is not malicious. As an additional security mechanism, the content may optionally only be stored in the file server (operation  208 )/database (operation  206 ) in response to a determination that a user requesting the storage has permission to save content. 
     Moreover, as shown in operation  210 , a reference identifier associated with the content is stored in a field of a record of the entity table. In one embodiment, the record may include a record specific to the entity with which the content is associated. For example, the record may include an identifier of the entity. In another embodiment, the field of the record may include a field that is configured (e.g. by an administrator, etc.) to store references for the type of the content. 
     It should be noted that in the context of the present embodiment, the reference identifier may include an identifier or other code which references the content. Furthermore, as shown in operation  212 , a content identifier for the content is stored in a field data table (e.g. of the database) in association with the reference identifier. For example, the field data table may include record storing the reference identifier in one field and the content identifier in another field. To this end, the reference identifier may be identified in the entity table and used to query the field data table for the associated content identifier. 
     Still yet, metadata, including a location of the content, is stored in at least one reference table (e.g. of the database), in association with the content identifier. Note operation  214 . To this end, the metadata may include an identifier of the location of the content, such as an address in the file system at which the content is stored. For example, a record of the reference table may store the content identifier and the associated metadata. In this way, the content identifier may be identified from the field data table (as described above) and used to query the reference table for the identifier of the location of the content. The identifier of the location of the content may then be used to retrieve the content from the file system whenever a request for the content is issued. 
     As an option, the reference table may also store (in association with the content identifier) an indicator of a number of different reference identifiers associated with the content identifier. For example, the record of the reference table storing the metadata and the content identifier may also store a count of a number of different reference identifiers associated with the content identifier. In one embodiment, such number may be determined from the field data table by counting a number of occurrences of the content identifier across the records of the field data table. The number may optionally be updated periodically (e.g. by counting a number of occurrences of the particular reference identifier stored in the entity table or by updating the count based on a logged number of insertions of the reference identifier in the reference table) or upon storage of the reference identifier in a record of the entity table. 
     The indicator of the number of different reference identifiers associated with the content identifier may then be used for determining whether to delete the content from the file server. For example, upon a deletion of a reference identifier from the entity table (e.g. upon a tenant requesting deletion of the content from the entity or deletion of the record storing the reference identifier from the entity table), the reference table may be updated to reflect one less reference identifier in the associated count. The count may then be queried to determine whether any other reference identifiers are associated with the content identifier (i.e. if the count is greater than zero). 
     If there is at least one other reference identifier associated with the content identifier, the content may be prevented from being deleted from the file system. If, however, there is not any other reference identifiers are associated with the content identifier, the content may be deleted from the system. Of course, it should be noted that such query of the count may also be initiated periodically, for example, by determining from a log whether the content has been deleted from an entity (e.g. instead of only upon a deletion of a reference identifier from the entity table). 
       FIG. 3  illustrates tables of a database system  300  configured to reference content stored outside of the database, in accordance with an embodiment. As an option, the database system  300  may be implemented in the context of the functionality of  FIGS. 1-2 . For example, the database system  300  may be implemented by the multi-tenant on-demand database system described herein. Of course, however, the database system  300  may be implemented in any desired environment. Again, the aforementioned definitions may apply during the present description. 
     As shown, each record of an entity table stores a tenant identifier (ORG ID), an entity identifier (EID) indicating an entity with Which the record is associated. For each record, a plurality of fields (FIELD  1  . . . N) may store data for the entity associated with the record. For example, the data may be used to configure the entity. Optionally, each of the fields may he configured to store a particular type of data. 
     In the present embodiment, each of the record shown in the entity table stores a reference identifier (FFID 1 , FFID 2  respectively) to content stored in the entity table for an associated entity. Additionally, a field data table also stores in each record a tenant identifier (ORG ID), and at least one field including a reference identifier (FFID 1 , FFID 2 ). In association with the reference identifier (FFID 1 , FFID 2 ), a content identifier (CRID_X) is stored. In the present embodiment shown, each of the reference identifiers (FFID 1 , FFID 2 ) is associated with a same content identifier, indicating that each of the reference identifiers (FFID 1 , FFID 2 ) references the same content in a file system. 
     A record of the reference table stores the content identifier (CRID_X) and metadata associated therewith. As shown, the metadata includes an identifier of a location (XXXX) of the content identified by the content identifier. Thus, in response to a request to access the content, the database system  300  shown may be utilized as follows to grant the access: identify the reference identifier associated with the content from the entity table, identify from the field data table the content identifier associated with the reference identifier, identify from the reference table the identifier of the location of the content associated with the content identifier, and retrieve the content from the file system using the identifier of the location of the content. 
     The record of the reference table also stores a count of a number of reference identifiers (FFID 1 , FFID 2 ) associated with the content identifier, which are stored in the field data table. This count may be used to determine when no references to the content exist in the database system  300 , such that the content may be deleted from the file system. 
     Furthermore, a record of a content table stores, in association with the content identifier (CRID_X), other metadata associated with the content. For example, such metadata may include a name of the content, a body of the content, a type of the content, a length of the content, etc. Thus, as an option, information associated with the content may be retrieved from the content table, using the reference identifier associated with the content, instead of determining the information from the content itself each time the information is requested (e.g. by a tenant, etc.). 
     In one embodiment, a query may be used to access the metadata. For example, if a user submits the query “select myFileField_contentType, myFileField_length from myObject”, the user&#39;s query may be translated into a query statement (i.e. in a query language) to generate a statement that joins the entity table with the field data table with the reference table with the content table to retrieve the content type column and the length column, without reading the actual stored content (e.g. the file contents). To this end, a query may be used to retrieve or filter by the metadata fields of the content table. 
     As a further option, the metadata may also include a flag indicating whether a type of the content has been changed. For example, a tenant may request that the content be converted from a first format to a second format (and thus a field storing the content be converted from being configured to store content of the first format to be configured to store content of the second format), such as from a long text area format to a rich text area format. In response to the conversion, a flag may be set in the metadata. If the converted content is changed back to its original format (e.g. from rich text area format to long text area format), the flag may be removed from the metadata. Of course, it should he noted that the metadata described above with respect to the content table may instead be stored in the reference table, in another embodiment (e.g. such that the content table may not necessarily exist in the database system  300 ). 
     In some embodiment, the content may be incapable of being converted, so any conversion of the content may result in a conversion of the configuration of the field, but a loss of the content. Optionally, converting content from a rich text area type to a plain text type may finding all data rows for the entity that have a non-null value for the associated field, parse to strip out all the rich text area [e.g. hypertext transfer markup language (HTML)] tags and formatting, truncating the result to 255 character, and converting a maximum length for the field to 255, and similarly converting a default value associated with the field to the text type. A similar conversion may be used when converting to a text area type and/or uniform resource locator (URL) type. 
       FIG. 4  illustrates a system  400  for using a database to access content stored outside of the database, in accordance with an embodiment. As an option, the system  400  may be implemented in the context of the functionality of  FIGS. 1-3 . Of course, however, the system  400  may be implemented in any desired environment. Again, the aforementioned definitions may apply during the present description. 
     Saving Content to the Multi-Tenant On-Demand Database System 
     As shown, a user device  402  uploads or otherwise sends content to a multi-tenant on-demand database system  401  via a network  404 . The user device  402  may include a computer of a tenant of the multi-tenant on-demand database system  401 , for example. The content is sent from the user device  402  with a request to store the content in association with an entity created within the multi-tenant on-demand database system  401 . In the present embodiment, such entity is an entity page  414  (e.g. webpage) of the tenant and the content is an image. It should be noted, however, that any entity and associated content may be utilized in at least a similar context as that described herein. 
     In response to receipt of the image, the method  200  of  FIG. 2  may be carried out by an image upload  406  module (e.g. application) for storing the image in the multi-tenant on-demand database system  401 . For example, if the image is of a type capable of being stored by a database  410 , the image may be stored in the database  410 . Optionally, global data  412  may store information associated with various content types (e.g. a format of the content types, etc.), such that storage of the image in the database  410  may include storing the image in a field of the database configured to store a type of the content (i.e. an image or a type of the image), where such configuration is performed using the global data  412 . If, however, the content is of a type incapable of being stored by the database  410 , the content may be stored in a file server  408 . It should be noted that in one embodiment the database  410  may take the form of the database system  300  shown in  FIG. 3 . 
     In one exemplary embodiment, receiving an image for storage and retrieving the image from storages may include the following steps shown in Table 1. Of course, the steps shown in Table 1 are set forth for illustrative purposes only and should not be construed as limiting in any manner. 
     
       
         
           
               
             
               
                 TABLE 1 
               
               
                   
               
             
            
               
                 1. A HTTP POST request to the image servlet 316 from the user device 
               
               
                 302 passing the image contents as multi-part form data. 
               
               
                 2. Upload the file to the server and insert a record in a reference table with 
               
               
                 USE_COUNT = 0 and invoke the entity save logic for a content table 
               
               
                 which will insert a record in the content table and insert the image file in 
               
               
                 the file server 308. 
               
               
                 3. The image servlet 316 will return a response: if the image is 
               
               
                 successfully uploaded a response to the user device will include the URL 
               
               
                 to another servlet, with the parameters required to retrieve the image from 
               
               
                 the file server 308; if the upload fails then an error message will be 
               
               
                 returned to the user device 302. 
               
               
                 4. The user device 302 will insert an image tag into a rich text editor of a 
               
               
                 GUI displayed via a browser of the user device 302, for referencing the 
               
               
                 URL. 
               
               
                 5. The browser of the user device 302 will make a request to the image 
               
               
                 servlet 316 which will retrieve the meta-data associated with the image 
               
               
                 from the content table and reference table. This meta-data will include 
               
               
                 the file server 308 locator (and optionally version identifier) to retrieve 
               
               
                 the image from the file server 308. 
               
               
                   
               
            
           
         
       
     
     As an option, the multi-tenant on-demand database system  401  may regulate an amount of content allowed to be stored by each tenant. For example, a threshold may be configured for each tenant indicating the maximum amount (e.g. size) of total content allowed to be stored in the multi-tenant on-demand database system  401  by a particular tenant. In one embodiment, each separate reference to a single piece of content may not necessarily be individually counted against the threshold. Thus, instead only the single piece of content stored in the file server  408  may count against the threshold. In another embodiment, if multiple tenants reference the same content, the storage of the content may be counted against the tenant who first stored a reference to the content. 
     Retrieving Content from the Multi-Tenant On-Demand Database System 
     In response to a request from the user device  402  for the entity page  414 , it may be confirmed that the user of the user device  402  has permissions to access the entity page  414 . For example, such permissions may be configured by the multi-tenant on-demand database system  401 . In response to a determination that the user has permissions to access the entity page  414 , the image may be retrieved from the multi-tenant on-demand database system  401  for inclusion in the entity page  314 , such that display of the entity page  414  to the user of the user device  402  includes the image. 
     Such retrieval may be performed using an image servlet  416  of the multi-tenant on-demand database system  401 . If the image is stored in the database  410 , the image servlet  416  may query the database  410  for the image (note, communication direction is not shown between image servlet  416  an database  410 ). If, however, the image is stored in the file server  408 , then a reference to the image stored in the database  410  may be used to retrieve the image from the file server  408 . In particular, metadata referencing the location of the image in the file server  408  may be identified and used to retrieve the image from the identified location in the file server  408  (e.g. as described above with respect to the database system  300  of  FIG. 3 ). 
       FIGS. 5A-5F  are screen shots illustrating examples of a user interface screen capable of being used to configure a database to reference content stored outside of the database, in accordance with an embodiment. As an option, the screen shots may be provided in the context of the functionality of  FIGS. 1-4 . For example, the screen shots may be provided by the multi-tenant on-demand database system described herein. Of course, however, the screen shots may be provided in any desired environment. Again, the aforementioned definitions may apply during the present description. 
     As shown in  FIG. 5A , a field of a table in a database may be configured to store content of a particular type. Such table may include the entity table described above with reference to  FIG. 3 , for example. The screenshot of  FIG. 5A  highlights that a field may be configured to store content that is of a rich text area type. Of course, in other embodiments, the field may be configured to store content that is of a file type, an image type, etc. 
     As shown in  FIG. 5B , details for the field configured in  FIG. 5B  may be entered. The details may include an identifier of the field (Field Label), a maximum allowed length for data stored in the field, a number of visible lines included in the field, a name of the field, a description of the field, help text associated with the field, and a default value to be stored in the field (e.g. which may be of the type of content for which the field is configured). 
       FIG. 5C  shows a screenshot for the configured field of  FIGS. 5A  and/or  5 B which may be used to configure permissions for editing (or optionally other types of access to) contents of the field. As shown, various types of users (i.e. according to user role) may be selected for being allowed editing permissions with respect to the field. 
       FIG. 5D  shows a screenshot for selecting which of a plurality of existing entities are to include the contents of the field. The existing entities may include entities created by a tenant who is configuring the field. In the embodiment shown, each entity may include a page layout for a different type of contact. 
       FIG. 5E  shows a screenshot for receiving content from a user for storage in the configured field. In the embodiment shown, the myHTMLField provides a set of tools for formatting text entered in a text box. The formatted text may then be saved in the configured field (e.g. in a rich text area format). 
       FIG. 5F  shows a screenshot for updating a configuration of a field. As shown, the details entered with respect to  FIG. 5B  may he modified, the permissions configured with respect to  FIG. 5C  may be modified, etc. 
     System Overview 
       FIG. 6  illustrates a block diagram of an environment  610  wherein an on-demand database service might be used. Environment  610  may include user systems  612 , network  614 , system  616 , processor system  617 , application platform  618 , network interface  620 , tenant data storage  622 , system data storage  624 , program code  626 , and process space  628 . In other embodiments, environment  610  may not have all of the components listed and/or may have other elements instead of, or in addition to, those listed above. 
     Environment  610  is an environment in which an on-demand database service exists. User system  612  may be any machine or system that is used by a user to access a database user system. For example, any of user systems  612  can be a handheld computing device, a mobile phone, a laptop computer, a work station, and/or a network of computing devices. As illustrated in  FIG. 6  (and in more detail in  FIG. 7 ) user systems  612  might interact via a network  614  with an on-demand database service, which is system  616 . 
     An on-demand database service, such as system  616 , is a database system that is made available to outside users that do not need to necessarily be concerned with building and/or maintaining the database system, but instead may be available for their use when the users need the database system (e.g., on the demand of the users). Some on-demand database services may store information from one or more tenants stored into tables of a common database image to form a multi-tenant database system (MTS). Accordingly, “on-demand database service  616 ” and “system  616 ” will be used interchangeably herein. A database image may include one or more database objects. A relational database management system (RDMS) or the equivalent may execute storage and retrieval of information against the database object(s). Application platform  618  may be a framework that allows the applications of system  616  to run, such as the hardware and/or software, e.g., the operating system. In an embodiment, on-demand database service  616  may include an application platform  618  that enables creation, managing and executing one or more applications developed by the provider of the on-demand database service, users accessing the on-demand database service via user systems  612 , or third party application developers accessing the on-demand database service via user systems  612 . 
     The users of user systems  612  may differ in their respective capacities, and the capacity of a particular user system  612  might be entirely determined by permissions (permission levels) for the current user. For example, where a salesperson is using a particular user system  612  to interact with system  616 , that user system has the capacities allotted to that salesperson. However, while an administrator is using that user system to interact with system  616 , that user system has the capacities allotted to that administrator. In systems with a hierarchical role model, users at one permission level may have access to applications, data, and database information accessible by a lower permission level user, but may not have access to certain applications, database information, and data accessible by a user at a higher permission level. Thus, different users will have different capabilities with regard to accessing and modifying application and database information, depending on a user&#39;s security or permission level. 
     Network  614  is any network or combination of networks of devices that communicate with one another. For example, network  614  can be any one or any combination of a LAN (local area network), WAN (wide area network), telephone network, wireless network, point-to-point network, star network, token ring network, hub network, or other appropriate configuration. As the most common type of computer network in current use is a TCP/IP (Transfer Control Protocol and Internet Protocol) network, such as the global internetwork of networks often referred to as the “Internet” with a capital “I,” that network will be used in many of the examples herein. However, it should be understood that the networks that the one or more implementations might use are not so limited, although TCP/IP is a frequently implemented protocol. 
     User systems  612  might communicate with system  616  using TCP/IP and, at a higher network level, use other common Internet protocols to communicate, such as HTTP, FTP, AFS, WAP, etc. In an example where HTTP is used, user system  612  might include an HTTP client commonly referred to as a “browser” for sending and receiving HTTP messages to and from an HTTP server at system  616 . Such an HTTP server might be implemented as the sole network interface between system  616  and network  614 , but other techniques might be used as well or instead. In some implementations, the interface between system  616  and network  614  includes load sharing functionality, such as round-robin HTTP request distributors to balance loads and distribute incoming HTTP requests evenly over a plurality of servers. At least as for the users that are accessing that server, each of the plurality of servers has access to the MTS′ data; however, other alternative configurations may be used instead. 
     In one embodiment, system  616 , shown in  FIG. 6 , implements a web-based customer relationship management (CRM) system. For example, in one embodiment, system  616  includes application servers configured to implement and execute CRM software applications as well as provide related data, code, forms, webpages and other information to and from user systems  612  and to store to, and retrieve from, a database system related data, objects, and Webpage content. With a multi-tenant system, data for multiple tenants may be stored in the same physical database object, however, tenant data typically is arranged so that data of one tenant is kept logically separate from that of other tenants so that one tenant does not have access to another tenant&#39;s data, unless such data is expressly shared. In certain embodiments, system  616  implements applications other than, or in addition to, a CRM application. For example, system  616  may provide tenant access to multiple hosted (standard and custom) applications, including a CRM application. User (or third party developer) applications, which may or may not include CRM, may be supported by the application platform  618 , which manages creation, storage of the applications into one or more database objects and executing of the applications in a virtual machine in the process space of the system  616 . 
     One arrangement for elements of system  616  is shown in  FIG. 6 , including a network interface  620 , application platform  618 , tenant data storage  622  for tenant data  623 , system data storage  624  for system data  625  accessible to system  616  and possibly multiple tenants, program code  626  for implementing various functions of system  616 , and a process space  628  for executing MTS system processes and tenant-specific processes, such as running applications as part of an application hosting service. Additional processes that may execute on system  616  include database indexing processes. 
     Several elements in the system shown in  FIG. 6  include conventional, well-known elements that are explained only briefly here. For example, each user system  612  could include a desktop personal computer, workstation, laptop, PDA, cell phone, or any wireless access protocol (WAP) enabled device or any other computing device capable of interfacing directly or indirectly to the Internet or other network connection. User system  612  typically runs an HTTP client, e.g., a browsing program, such as Microsoft&#39;s Internet Explorer browser, Netscape&#39;s Navigator browser, Opera&#39;s browser, or a WAP-enabled browser in the case of a cell phone, PDA or other wireless device, or the like, allowing a user (e.g., subscriber of the multi-tenant database system) of user system  612  to access, process and view information, pages and applications available to it from system  616  over network  614 . Each user system  612  also typically includes one or more user interface devices, such as a keyboard, a mouse, trackball, touch pad, touch screen, pen or the like, for interacting with a graphical user interface (GUI) provided by the browser on a display (e.g., a monitor screen, LCD display, etc.) in conjunction with pages, forms, applications and other information provided by system  616  or other systems or servers. For example, the user interface device can be used to access data and applications hosted by system  616 , and to perform searches on stored data, and otherwise allow a user to interact with various GUI pages that may be presented to a user. As discussed above, embodiments are suitable for use with the Internet, which refers to a specific global internetwork of networks. However, it should be understood that other networks can be used instead of the Internet, such as an intranet, an extranet, a virtual private network (VPN), a non-TCP/IP based network, any LAN or WAN or the like. 
     According to one embodiment, each user system  612  and all of its components are operator configurable using applications, such as a browser, including computer code run using a central processing unit such as an Intel Pentium® processor or the like. Similarly, system  616  (and additional instances of an MTS, where more than one is present) and all of their components might be operator configurable using application(s) including computer code to run using a central processing unit such as processor system  617 , which may include an Intel Pentium® processor or the like, and/or multiple processor units. A computer program product embodiment includes a machine-readable storage medium (media) having instructions stored thereon/in which can be used to program a computer to perform any of the processes of the embodiments described herein. Computer code for operating and configuring system  616  to intercommunicate and to process webpages, applications and other data and media content as described herein are preferably downloaded and stored on a hard disk, but the entire program code, or portions thereof, may also be stored in any other volatile or non-volatile memory medium or device as is well known, such as a ROM or RAM, or provided on any media capable of storing program code, such as any type of rotating media including floppy disks, optical discs, digital versatile disk (DVD), compact disk (CD), microdrive, and magneto-optical disks, and magnetic or optical cards, nanosystems (including molecular memory ICs), or any type of media or device suitable for storing instructions and/or data. Additionally, the entire program code, or portions thereof, may be transmitted and downloaded from a software source over a transmission medium, e.g., over the Internet, or from another server, as is well known, or transmitted over any other conventional network connection as is well known (e.g., extranet, VPN, LAN, etc.) using any communication medium and protocols (e.g., TCP/IP, HTTP, HTTPS, Ethernet, etc.) as are well known. It will also be appreciated that computer code for implementing embodiments can be implemented in any programming language that can be executed on a client system and/or server or server system such as, for example, C, C++, HTML, any other markup language, Java™, JavaScript, ActiveX, any other scripting language, such as VBScript, and many other programming languages as are well known may be used. (Java™ is a trademark of Sun Microsystems, Inc.). 
     According to one embodiment, each system  616  is configured to provide webpages, forms, applications, data and media content to user (client) systems  612  to support the access by user systems  612  as tenants of system  616 . As such, system  616  provides security mechanisms to keep each tenant&#39;s data separate unless the data is shared. If more than one MTS is used, they may be located in close proximity to one another (e.g., in a server farm located in a single building or campus), or they may be distributed at locations remote from one another (e.g., one or more servers located in city A and one or more servers located in city B). As used herein, each MTS could include one or more logically and/or physically connected servers distributed locally or across one or more geographic locations. Additionally, the term “server” is meant to include a computer system, including processing hardware and process space(s), and an associated storage system and database application (e.g., OODBMS or RDBMS) as is well known in the art. It should also be understood that “server system” and “server” are often used interchangeably herein. Similarly, the database object described herein can be implemented as single databases, a distributed database, a collection of distributed databases, a database with redundant online or offline backups or other redundancies, etc., and might include a distributed database or storage network and associated processing intelligence. 
       FIG. 7  also illustrates environment  610 . However, in  FIG. 7  elements of system  616  and various interconnections in an embodiment are further illustrated.  FIG. 7  shows that user system  612  may include processor system  612 A, memory system  612 B, input system  612 C, and output system  612 D.  FIG. 7  shows network  614  and system  616 .  FIG. 7  also shows that system  616  may include tenant data storage  622 , tenant data  623 , system data storage  624 , system data  625 , User Interface (UI)  730 , Application Program Interface (API)  732 , PL/SOQL  734 , save routines  736 , application setup mechanism  738 , applications servers  700   1 - 700   N,  system process space  702 , tenant process spaces  704 , tenant management process space  710 , tenant storage area  712 , user storage  714 , and application metadata  716 . In other embodiments, environment  610  may not have the same elements as those listed above and/or may have other elements instead of, or in addition to, those listed above. 
     User system  612 , network  614 , system  616 , tenant data storage  622 , and system data storage  624  were discussed above in  FIG. 6 . Regarding user system  612 , processor system  612 A may be any combination of one or more processors. Memory system  612 B may he any combination of one or more memory devices, short term, and/or long term memory. Input system  612 C may be any combination of input devices, such as one or more keyboards, mice, trackballs, scanners, cameras, and/or interfaces to networks. Output system  612 D may be any combination of output devices, such as one or more monitors, printers, and/or interfaces to networks. As shown by  FIG. 7 , system  616  may include a network interface  620  (of  FIG. 6 ) implemented as a set of HTTP application servers  700 , an application platform  618 , tenant data storage  622 , and system data storage  624 . Also shown is system process space  702 , including individual tenant process spaces  704  and a tenant management process space  710 . Each application server  700  may be configured to tenant data storage  622  and the tenant data  623  therein, and system data storage  624  and the system data  625  therein to serve requests of user systems  612 . The tenant data  623  might be divided into individual tenant storage areas  712 , which can be either a physical arrangement and/or a logical arrangement of data. Within each tenant storage area  712 , user storage  714  and application metadata  716  might be similarly allocated for each user. For example, a copy of a user&#39;s most recently used (MRU) items might be stored to user storage  714 . Similarly, a copy of MRU items for an entire organization that is a tenant might be stored to tenant storage area  712 . A UI  730  provides a user interface and an API  732  provides an application programmer interface to system  616  resident processes to users and/or developers at user systems  612 . The tenant data and the system data may be stored in various databases, such as one or more Oracle™ databases. 
     Application platform  618  includes an application setup mechanism  738  that supports application developers&#39; creation and management of applications, which may be saved as metadata into tenant data storage  622  by save routines  736  for execution by subscribers as one or more tenant process spaces  704  managed by tenant management process  710  for example. As an option, the application platform  618  may further include a search system  740 . Invocations to such applications may be coded using PL/SOQL  734  that provides a programming language style interface extension to API  732 . A detailed description of some PL/SOQL language embodiments is discussed in commonly owned co-pending U.S. Provisional Patent Application 60/828,192 entitled, PROGRAMMING LANGUAGE METHOD AND SYSTEM FOR EMENDING APIS TO EXECUTE IN CONJUNCTION WITH DATABASE APIS, by Craig Weissman, filed Oct. 4, 2006, which is incorporated in its entirety herein for all purposes. Invocations to applications may be detected by one or more system processes, which manages retrieving application metadata  716  for the subscriber making the invocation and executing the metadata as an application in a virtual machine. 
     Each application server  700  may be communicably coupled to database systems, e.g., having access to system data  625  and tenant data  623 , via a different network connection. For example, one application server  700   1  might be coupled via the network  614  (e.g., the Internet), another application server  700   N-1  might he coupled via a direct network link, and another application server  700   N  might be coupled by yet a different network connection. Transfer Control Protocol and Internet Protocol (TCP/IP) are typical protocols for communicating between application servers  700  and the database system. However, it will be apparent to one skilled in the art that other transport protocols may be used to optimize the system depending on the network interconnect used. 
     In certain embodiments, each application server  700  is configured to handle requests for any user associated with any organization that is a tenant. Because it is desirable to be able to add and remove application servers from the server pool at any time for any reason, there is preferably no server affinity for a user and/or organization to a specific application server  700 . In one embodiment, therefore, an interface system implementing a load balancing function (e.g., an F5 Big-IP load balancer) is communicably coupled between the application servers  700  and the user systems  612  to distribute requests to the application servers  700 . In one embodiment, the load balancer uses a least connections algorithm to route user requests to the application servers  700 . Other examples of load balancing algorithms, such as round robin and observed response time, also can be used. For example, in certain embodiments, three consecutive requests from the same user could hit three different application servers  700 , and three requests from different users could hit the same application server  700 . In this manner, system  616  is multi-tenant, wherein system  616  handles storage of, and access to, different objects, data and applications across disparate users and organizations. 
     As an example of storage, one tenant might be a company that employs a sales force where each salesperson uses system  616  to manage their sales process. Thus, a user might maintain contact data, leads data, customer follow-up data, performance data, goals and progress data, etc., all applicable to that user&#39;s personal sales process (e.g., in tenant data storage  622 ). In an example of a MTS arrangement, since all of the data and the applications to access, view, modify, report, transmit, calculate, etc., can be maintained and accessed by a user system having nothing more than network access, the user can manage his or her sales efforts and cycles from any of many different user systems. For example, if a salesperson is visiting a customer and the customer has Internet access in their lobby, the salesperson can obtain critical updates as to that customer while waiting for the customer to arrive in the lobby. 
     While each user&#39;s data might be separate from other users&#39; data regardless of the employers of each user, some data might be organization-wide data shared or accessible by a plurality of users or all of the users for a given organization that is a tenant. Thus, there might be some data structures managed by system  616  that are allocated at the tenant level while other data structures might be managed at the user level. Because an MTS might support multiple tenants including possible competitors, the MTS should have security protocols that keep data, applications, and application use separate. Also, because many tenants may opt for access to an MTS rather than maintain their own system, redundancy, up-time, and backup are additional functions that may be implemented in the MTS. In addition to user-specific data and tenant specific data, system  616  might also maintain system level data usable by multiple tenants or other data. Such system level data might include industry reports, news, postings, and the like that are sharable among tenants. 
     In certain embodiments, user systems  612  (which may be client systems) communicate with application servers  700  to request and update system-level and tenant-level data from system  616  that may require sending one or more queries to tenant data storage  622  and/or system data storage  624 . System  616  (e.g., an application server  700  in system  616 ) automatically generates one or more SQL statements (e.g., one or more SQL queries) that are designed to access the desired information. System data storage  624  may generate query plans to access the requested data from the database. 
     Each database can generally be viewed as a collection of objects, such as a set of logical tables, containing data fitted into predefined categories. A “table” is one representation of a data object, and may be used herein to simplify the conceptual description of objects and custom objects. It should be understood that “table” and “object” may be used interchangeably herein. Each table generally contains one or more data categories logically arranged as columns or fields in a viewable schema. Each row or record of a table contains an instance of data for each category defined by the fields. For example, a CRM database may include a table that describes a customer with fields for basic contact information such as name, address, phone number, fax number, etc. Another table might describe a purchase order, including fields for information such as customer, product, sale price, date, etc. In some multi-tenant database systems, standard entity tables might be provided for use by all tenants. For CRM database applications, such standard entities might include tables for Account, Contact, Lead, and Opportunity data, each containing pre-defined fields. It should be understood that the word “entity” may also be used interchangeably herein with “object” and “table”. 
     In some multi-tenant database systems, tenants may be allowed to create and store custom objects, or they may be allowed to customize standard entities or objects, for example by creating custom fields for standard objects, including custom index fields. U.S. patent application Ser. No. 10/817,161, filed Apr. 2, 2004, entitled “Custom Entities and Fields in a Multi-Tenant Database System”, and which is hereby incorporated herein by reference, teaches systems and methods for creating custom objects as well as customizing standard objects in a multi-tenant database system. In certain embodiments, for example, all custom entity data rows are stored in a single multi-tenant physical table, which may contain multiple logical tables per organization. It is transparent to customers that their multiple “tables” are in fact stored in one large table or that their data may be stored in the same table as the data of other customers. 
     While one or more implementations have been described by way of example and in terms of the specific embodiments, it is to be understood that one or more implementations are not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.