INNER QUERY JOINS

• US 20140081950A1
• Filed: 09/16/2013
• Published: 03/20/2014
• Est. Priority Date: 09/14/2012
• Status: Active Grant

• Current Assignee: Salesforce.com, Inc.
• Original Assignee: Chirag Rajan, Hoon Kim, Jaikumar Bathija, Jesse Collins
• Inventors: RAJAN, CHIRAG, COLLINS, JESSE, BATHIJA, JAIKUMAR, KIM, HOON
• Granted Patent: US 10,152,511 B2
• Time in Patent Office: Days
• US Class Current: 707/715
• CPC Class Codes: G06F 16/24549 Run-time optimisation
• CPC Class Codes: G06F 16/2456 Join operations

Abstract

In an on demand database system, a query engine applies a custom index for inner queries. The query engine receives a query and determines that the query has an inner query nested within the primary query. The query engine identifies that a custom index exists for a client associated with the query, and applies the custom index to filter results for the query. The custom index includes a subset of information of a table that includes accounts for multiple different clients. By using the custom index, the query engine can filter the results more efficiently that if solely using the multiple client table.

Claims

1. A method comprising:

receiving a query at a query engine of an on demand database system, the query associated with a client of the on demand database system, where a single table of the on demand database system stores accounts for multiple different clients;

determining that the query has an inner query nested within the query;

identifying a custom index for the client that includes only a selected subset of entries of the single table; and

applying the custom index to filter results for the inner query prior to generating results for the query.

2. The method of claim 1, wherein the single table stores accounts for all clients of the on demand database system.

3. The method of claim 1, wherein the custom index includes a set of custom objects.

4. The method of claim 1, wherein the custom index includes a subset of entries specific to only one client of the on demand database system.

5. The method of claim 1, wherein determining the query has the inner query comprises parsing the query with the query engine into one or more inner queries with results to be combined as a result to the query.

6. The method of claim 1, wherein the on demand database system includes multiple databases referenced by the single table, and wherein each of the multiple databases includes a query optimizer specific to queries for the respective database.

7. The method of claim 6, wherein applying the custom index further comprises the query engine identifying the custom index to the query optimizers.

8. An article of manufacture comprising a computer readable storage medium having content stored thereon, which when executed, cause a machine to perform operations including:

receiving a query at a query engine of an on demand database system, the query associated with a client of the on demand database system, where a single table of the on demand database system stores accounts for multiple different clients;

determining that the query has an inner query nested within the query;

identifying a custom index for the client that includes only a selected subset of entries of the single table; and

applying the custom index to filter results for the inner query prior to generating results for the query.

9. The article of manufacture of claim 8, wherein the single table stores accounts for all clients of the on demand database system.

10. The article of manufacture of claim 8, wherein the custom index includes a set of custom objects.

11. The article of manufacture of claim 8, wherein the custom index includes a subset of entries specific to only one client of the on demand database system.

12. The article of manufacture of claim 8, wherein the content for determining the query has the inner query further comprises content for parsing the query with the query engine into one or more inner queries with results to be combined as a result to the query.

13. The article of manufacture of claim 8, wherein the on demand database system includes multiple databases referenced by the single table, and wherein each of the multiple databases includes a query optimizer specific to queries for the respective database.

14. The article of manufacture of claim 13, wherein the content for applying the custom index further comprises content for the query engine identifying the custom index to the query optimizers.

15. A computer system comprising:

network interface hardware to connect to a multitenant database system (MTS), wherein the MTS stores data for multiple client organizations each identified by a tenant identifier (ID) and one or more users are associated with the tenant ID, wherein the one or more users of each client organization access data identified by the tenant ID associated with the respective client organization, and wherein the multitenant database is hosted by an entity separate from the client organization; and

a processor device to execute a query engine for the MTS, configured to

receive a query associated with a client of the MTS, where a single table of the MTS stores accounts for multiple different clients;

determine that the query has an inner query nested within the query;

identify a custom index for the client that includes only a selected subset of entries of the single table; and

apply the custom index to filter results for the inner query prior to generating results for the query.

16. The computer system of claim 15, wherein the single table stores accounts for all clients of the on demand database system.

17. The computer system of claim 15, wherein the custom index includes a subset of entries specific to only one client of the on demand database system.

18. The computer system of claim 15, wherein the query engine is to determine the query has the inner query by parsing the query with the query engine into one or more inner queries with results to be combined as a result to the query.

19. The computer system of claim 15, wherein the MTS includes multiple databases referenced by the single table, and wherein each of the multiple databases includes a query optimizer specific to queries for the respective database.

20. The computer system of claim 19, wherein the query engine is to apply the custom index by identifying the custom index to the query optimizers.