CLAIM FOR PRIORITYThis application is a continuation of, and claims the benefit of, U.S. patent application Ser. No. 15/453,380 entitled “TECHNIQUES AND ARCHITECTURES FOR MAINTAINING METADATA VERSION CONTROLS”, filed Mar. 8, 2017, now U.S. Pat. No. 10,459,718 with an issue date of Oct. 29, 2019, the entire contents of which are incorporated herein by reference.
TECHNICAL FIELDEmbodiments relate to techniques for managing metadata within a computing environment. More particularly, embodiments relate to techniques for using a version control repository to maintain metadata.
BACKGROUNDMetadata is generally data about other data. Metadata is often used to store and/or communicate characteristics about data. For example, data can be stored in a file having associated metadata (e.g., file size, creation date). As environments that use and operate on data become more complex, so too does the need for metadata as well as the amount of metadata that must be managed. Traditional techniques for managing metadata can include maintaining change logs to track and manage changes to the metadata. However, use of change logs can be unnecessarily complex and inefficient.
BRIEF DESCRIPTION OF THE DRAWINGSEmbodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements.
FIG. 1 is a block diagram of one embodiment an architecture that can be utilized to manage metadata using a VCS.
FIG. 2 is a block diagram of one embodiment of a shared platform that can utilize a VCS as described herein.
FIG. 3 is a flow diagram of one embodiment of a technique for managing metadata using a VCS.
FIG. 4 illustrates a block diagram of an environment where an on-demand database service might be used.
FIG. 5 illustrates a block diagram of an environment where an on-demand database service might be used.
DETAILED DESCRIPTIONIn the following description, numerous specific details are set forth. However, embodiments of the invention may be practiced without these specific details. In other instances, well-known structures and techniques have not been shown in detail in order not to obscure the understanding of this description.
Described herein are techniques and architectures to utilize a version control system (VCS) to track metadata changes. This can be utilized, for example, to synchronize metadata between organizations/tenants/customers in a multitenant environment, or to synchronize metadata between environments (e.g., development to production). In one embodiment, as metadata changes are logged and exported as events, the events can be “decompiled” and exported as “source” files (e.g., XML based human readable form) and these source files can be processed by the VCS system.
This can be used, for example, to synchronize changes within orgs and changes made outside the orgs through development or synchronization. For example, a change can be made external to the org and when the corresponding source change is committed, the VCS can trigger an update to the org metadata.
As used herein “decompiled” metadata is metadata and/or custom metadata (metadata about metadata) that is in a format that is manageable by a VCS. That is, the process of “decompiling” can cause the metadata to change forms from its native form to one that can be consumed and/or managed by the VCS. Further, “metadata” refers to any data that describes other data or metadata (e.g., custom metadata) and can include code. The term “source” object or “source” code or “source” file refers to objects/files having decompiled metadata and can take the form of, for example, text files, XML files, programming language files, APEX code, bytecode, etc. Conceptually, decompiling (or “deconstructing” or “reverse translation”) is a reversal of creating metadata from a source, which can be considered a type of compilation (or construction or translation).
By “compiling” the metadata and treating it as “source” objects/files, the underlying metadata can be more easily managed and coordinated using a VCS, for example, Subversion (SVN) available from the Apache Software Foundation, Git available from Software Freedom Conservancy, or Concurrent Versions System (CVS) available from Free Software Foundation. Maintaining metadata in this way allows for more efficient and less error-prone uses of metadata. For example, a new org can be created with a selected version of metadata, metadata versions can be quickly and easily rolled back, etc.
This process of “decompiling” to generate “source” files/objects is fundamentally different than the traditional process of utilizing change logs or change sets. The use of change logs or change sets requires that the changes listed in the log/set be reapplied from a known starting point. In contrast, the techniques described herein allow for source files and/or objects to be compiled from the VCS to allow the desired version to be achieved without the process of rolling back and then reapplying changes.
FIG. 1 is a block diagram of one embodiment an architecture that can be utilized to manage metadata using a VCS. In the example ofFIG. 1, multiple organizations/tenants/customers (orgs) are communicatively coupled with a version control system that has a sufficient storage capacity to store multiple versions of metadata for each org supported. Various architectures can be supported, for example, a multitenant, cloud-based architecture, an architecture in which the VCS services can be provided to multiple disparate orgs, an architecture in which the VCS manages metadata for one or more sub-groups within a single organization. Other and/or different configurations can also be supported.
In the example ofFIG. 1, compiling (constructing, translating) corresponds to VCS-to-org traffic and decompiling (deconstructing, reverse translating) corresponds to org-to-VCS traffic. In one embodiment, the decompiling occurs in response to metadata a change in the org (tenant, customer). In one embodiment, the compiling is initiated by a database trigger; however, other triggers can also be supported. In one embodiment, the data from the metadata is compiled into a source readable form (e.g., WL). In one embodiment, deserialization occurs when a change is pushed from the VCS based on, for example, a trigger, or when a change is pulled from the VCS by the org.
Network120 represents any interconnection between the other components ofFIG. 1.Network120 can be, for example, a local area network, the Internet, a bus structure within a computing system, etc. Network120 provides the functionality of moving metadata (e.g.,135,145,155) between one or more orgs (e.g.,130,140,150) andversion control system180.
As various orgs (e.g.,130,140,150) function, metadata (e.g.,135,145,155) can be created or changed. In one embodiment, in response to creation or change to metadata, the host org (or component thereof) can decompile the metadata (or changes to the metadata) to be sent toVCS180. In one embodiment, the org can provide the functionality of decompiling the metadata as described above. That is, the metadata (or changes to the metadata) can be converted to a format (e.g.,)ML file(s), text file(s), CSV files(s)) that is manageable byVCS180.
In one embodiment, when metadata is modified, the host org determines what changes have been made to the metadata as well as any dependencies and/or supporting changes that have been (or should be) made along with the changes to the metadata. One or more source files (i.e., decompiled versions of any metadata that has been changed) are sent to VCS180. In one embodiment, VCS180 utilizesdatabase185 to store and manage versions of the source files.
FIG. 2 is a block diagram of one embodiment of a shared platform that can utilize a VCS as described herein. The example ofFIG. 2 corresponds to multiple tenants/organizations/customers sharing a platform, but each having their own VCS configurations.
One or more remote devices (e.g.,210,212,214,218) can be utilized by users to access services provided byplatform230. The remote devices can be any type of electronic computing platform, for example, a laptop computer, a desktop computer, a tablet, a smartphone, a wearable computing device, a kiosk, etc.
Platform230 can provide services (e.g., Customer Relationship Management, shared database(s), inventory tracking, social media) to the one or more remote devices. In various embodiments, in order to provide services to multiple devices and/or multiple tenants/organizations/customers, metadata may be utilized to provide customizations. The customizations can be made, for example, by users of the remote devices.Platform230 can be any number of physical computing devices.
In one embodiment, each tenant/organization/customer can have their own VCS (e.g.,271,272,278) for use with files specific to the tenant/organization/customer. Different tenants/organizations/customers can have different VCS implementations. Thus, the files and corresponding formats may vary from VCS to VCS.
In one embodiment,platform230 includes compilingagent240 and decompilingagent250. In one embodiment, compilingagent240 and decompilingagent250 are shared by one or more (or all) of the tenants/organizations/customers ofplatform230. In one embodiment, compilingagent240 has access todata store245 that includes configuration information for the one or more VCS implementations that are supported. In one embodiment, decompilingagent250 has access todata store255 that includes configuration information for the one or more VCS implementations that are supported. Compilingagent240 and decompilingagent250 can provide the compiling and decompiling functionality described herein.
In one embodiment,platform manager260 supports or provides the functionality provided byplatform230. As discussed above,platform230 can provide a variety of services and functionality to any number of tenants/organizations/customers using one or more remote devices.
FIG. 3 is a flow diagram of one embodiment of a technique for managing metadata using a VCS. The techniques ofFIG. 3 can be provided, for example, by the components illustrated inFIG. 1, one or more of which can be part of an on-demand services environment, various embodiments of which are described in greater detail below with respect toFIGS. 4 and 5. Some embodiments can operate in a multitenant environment to provide support to multiple organizations/tenants/customers by sharing resources such as a database.
Changes to metadata can be detected,310. Various techniques can be utilized to determine whether a change has occurred. In one embodiment, when a change has been saved to an object or file, the technique ofFIG. 3 can be triggered. In another embodiment, the technique ofFIG. 3 can be explicitly triggered (e.g., through a command or graphical user interface menu or button) by a user (e.g., developer). As another alternative, metadata file comparisons can be performed at pre-selected intervals.
The detected changes are decompiled into a VCS-compatible format,320. This results in source objects/files that can be stored and managed with the VCS. As discussed above, the decompiled objects/files can be, for example, text files, XML files, programming language files, APEX code. In one embodiment, the process of decompiling the metadata includes providing linking and/or relationship information to indicate relationships between decompiled objects/files, if appropriate.
The source objects/files are sent to the VCS,330. In one embodiment, this may include transmitting the source objects/files over a network from the environment in which the metadata has been changed to a remote VCS. In another embodiment, the environment in which the metadata has been changed and the VCS are part of an integrated platform.
The VCS stores the source objects/files in the appropriate structure,340. In one embodiment, the VCS provides relationship and/or dependency information in the storage structure or in the versioning information to indicate relationships between decompiled objects/files, if appropriate.
The source objects/files stored in the VCS can be used for rolling back to previous versions of the metadata by extracting the source objects/files from the VCS. Comparison analysis can also be performed on the source objects/files in the VCS. Techniques for rolling back, or undoing, changes to metadata are described in greater detail in U.S. patent application Ser. No. 15/453,645, entitled “TECHNIQUES AND ARCHITECTURES FOR PROVIDING FUNCTIONALITY To UNDO A METADATA CHANGE” by James Bock Wunderlich, filed concurrently herewith, which is incorporated by reference herein.
As used herein, a “tenant” includes a group of users who share a common access with specific privileges to a software instance. A multi-tenant architecture provides a tenant with a dedicated share of the software instance typically including one or more of tenant specific data, user management, tenant-specific functionality, configuration, customizations, non-functional properties, associated applications, etc. Multi-tenancy contrasts with multi-instance architectures, where separate software instances operate on behalf of different tenants.
In various embodiments, the environments described with respect toFIGS. 4 and 5 can provide the platform discussed with respect toFIG. 2.
FIG. 4 illustrates a block diagram of anenvironment410 wherein an on-demand database service might be used.Environment410 may includeuser systems412,network414,system416,processor system417,application platform418,network interface420,tenant data storage422,system data storage424,program code426, andprocess space428. In other embodiments,environment410 may not have all of the components listed and/or may have other elements instead of, or in addition to, those listed above.
Environment410 is an environment in which an on-demand database service exists.User system412 may be any machine or system that is used by a user to access a database user system. For example, any ofuser systems412 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 hereinFIG. 4 (and in more detail inFIG. 5)user systems412 might interact via anetwork414 with an on-demand database service, which issystem416. In one embodiment,system416 utilizesmetadata430 as described herein.
An on-demand database service, such assystem416, 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 service416” and “system416” 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 platform418 may be a framework that allows the applications ofsystem416 to run, such as the hardware and/or software, e.g., the operating system. In an embodiment, on-demand database service416 may include anapplication platform418 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 viauser systems412, or third party application developers accessing the on-demand database service viauser systems412.
The users ofuser systems412 may differ in their respective capacities, and the capacity of aparticular user system412 might be entirely determined by permissions (permission levels) for the current user. For example, where a salesperson is using aparticular user system412 to interact withsystem416, that user system has the capacities allotted to that salesperson. However, while an administrator is using that user system to interact withsystem416, 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's security or permission level.
Network414 is any network or combination of networks of devices that communicate with one another. For example,network414 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 one or more implementations might use are not so limited, although TCP/IP is a frequently implemented protocol.
User systems412 might communicate withsystem416 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 system412 might include an HTTP client commonly referred to as a “browser” for sending and receiving HTTP messages to and from an HTTP server atsystem416. Such an HTTP server might be implemented as the sole network interface betweensystem416 andnetwork414, but other techniques might be used as well or instead. In some implementations, the interface betweensystem416 andnetwork414 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,system416, shown inFIG. 4, implements a web-based customer relationship management (CRM) system. For example, in one embodiment,system416 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 fromuser systems412 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's data, unless such data is expressly shared. In certain embodiments,system416 implements applications other than, or in addition to, a CRM application. For example,system416 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 theapplication platform418, 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 thesystem416.
One arrangement for elements ofsystem416 is shown inFIG. 4, including anetwork interface420,application platform418,tenant data storage422 fortenant data423,system data storage424 forsystem data425 accessible tosystem416 and possibly multiple tenants,program code426 for implementing various functions ofsystem416, and aprocess space428 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 onsystem416 include database indexing processes.
Several elements in the system shown inFIG. 4 include conventional, well-known elements that are explained only briefly here. For example, eachuser system412 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 system412 typically runs an HTTP client, e.g., a browsing program, such as Edge from Microsoft, Safari from Apple, Chrome from Google, 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) ofuser system412 to access, process and view information, pages and applications available to it fromsystem416 overnetwork414. Eachuser system412 also typically includes one or more user interface devices, such as a keyboard, a mouse, 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 bysystem416 or other systems or servers. For example, the user interface device can be used to access data and applications hosted bysystem416, 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, eachuser system412 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 Core series processor or the like. Similarly, system416 (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 asprocessor system417, which may include an Intel Core series 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 configuringsystem416 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, eachsystem416 is configured to provide webpages, forms, applications, data and media content to user (client)systems412 to support the access byuser systems412 as tenants ofsystem416. As such,system416 provides security mechanisms to keep each tenant'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. 5 also illustratesenvironment410. However, inFIG. 5 elements ofsystem416 and various interconnections in an embodiment are further illustrated.FIG. 5 shows thatuser system412 may includeprocessor system412A,memory system412B,input system412C, andoutput system412D.FIG. 5 showsnetwork414 andsystem416.FIG. 5 also shows thatsystem416 may includetenant data storage422,tenant data423,system data storage424,system data425, User Interface (UI)530, Application Program Interface (API)532, PL/SOQL534, saveroutines536,application setup mechanism538, applications servers5001-500N,system process space502,tenant process spaces504, tenantmanagement process space510,tenant storage area512,user storage514, andapplication metadata516. In other embodiments,environment410 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 system412,network414,system416,tenant data storage422, andsystem data storage424 were discussed above inFIG. 4. Regardinguser system412,processor system412A may be any combination of one or more processors.Memory system412B may be any combination of one or more memory devices, short term, and/or long term memory.Input system412C may be any combination of input devices, such as one or more keyboards, mice, trackballs, scanners, cameras, and/or interfaces to networks.Output system412D may be any combination of output devices, such as one or more monitors, printers, and/or interfaces to networks. As shown byFIG. 5,system416 may include a network interface420 (ofFIG. 4) implemented as a set ofHTTP application servers500, anapplication platform418,tenant data storage422, andsystem data storage424. Also shown issystem process space502, including individualtenant process spaces504 and a tenantmanagement process space510. Eachapplication server500 may be configured to tenantdata storage422 and thetenant data423 therein, andsystem data storage424 and thesystem data425 therein to serve requests ofuser systems412. Thetenant data423 might be divided into individualtenant storage areas512, which can be either a physical arrangement and/or a logical arrangement of data. Within eachtenant storage area512,user storage514 andapplication metadata516 might be similarly allocated for each user. For example, a copy of a user's most recently used (MRU) items might be stored touser storage514. Similarly, a copy of MRU items for an entire organization that is a tenant might be stored to tenantstorage area512. AUI530 provides a user interface and anAPI532 provides an application programmer interface tosystem416 resident processes to users and/or developers atuser systems412. The tenant data and the system data may be stored in various databases, such as one or more Oracle™ databases.
Application platform418 includes anapplication setup mechanism538 that supports application developers' creation and management of applications, which may be saved as metadata intotenant data storage422 by saveroutines536 for execution by subscribers as one or moretenant process spaces504 managed bytenant management process510 for example. Invocations to such applications may be coded using PL/SOQL534 that provides a programming language style interface extension toAPI532. A detailed description of some PL/SOQL language embodiments is discussed in commonly owned U.S. Pat. No. 7,730,478 entitled, “Method and System for Allowing Access to Developed Applicants via a Multi-Tenant Database On-Demand Database Service”, issued Jun. 1, 2010 to Craig Weissman, which is incorporated in its entirety herein for all purposes. Invocations to applications may be detected by one or more system processes, which manage retrievingapplication metadata516 for the subscriber making the invocation and executing the metadata as an application in a virtual machine.
Eachapplication server500 may be communicably coupled to database systems, e.g., having access tosystem data425 andtenant data423, via a different network connection. For example, oneapplication server5001might be coupled via the network414 (e.g., the Internet), another application server500N-1might be coupled via a direct network link, and anotherapplication server500Nmight be coupled by yet a different network connection. Transfer Control Protocol and Internet Protocol (TCP/IP) are typical protocols for communicating betweenapplication servers500 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, eachapplication server500 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 aspecific application server500. In one embodiment, therefore, an interface system implementing a load balancing function (e.g., an F5 BIG-IP load balancer) is communicably coupled between theapplication servers500 and theuser systems412 to distribute requests to theapplication servers500. In one embodiment, the load balancer uses a least connections algorithm to route user requests to theapplication servers500. 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 threedifferent application servers500, and three requests from different users could hit thesame application server500. In this manner,system416 is multi-tenant, whereinsystem416 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 usessystem416 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's personal sales process (e.g., in tenant data storage422). 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's data might be separate from other users' 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 bysystem416 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,system416 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 systems412 (which may be client systems) communicate withapplication servers500 to request and update system-level and tenant-level data fromsystem416 that may require sending one or more queries to tenantdata storage422 and/orsystem data storage424. System416 (e.g., anapplication server500 in system416) automatically generates one or more SQL statements (e.g., one or more SQL queries) that are designed to access the desired information.System data storage424 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.
Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
While the invention has been described in terms of several embodiments, those skilled in the art will recognize that the invention is not limited to the embodiments described, but can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is thus to be regarded as illustrative instead of limiting.