TRUNCATING DATA ASSOCIATED WITH OBJECTS IN A MULTI-TENANT DATABASE

• US 20130007062A1
• Filed: 11/01/2011
• Published: 01/03/2013
• Est. Priority Date: 07/01/2011
• Status: Active Grant

• Current Assignee: Salesforce.com, Inc.
• Original Assignee: Salesforce.com, Inc.
• Inventors: Dutta, Arup, Wong, Simon, Macklem, Walter, Soble, Dan, Black, Nathanael
• Granted Patent: US 9,069,788 B2
• Time in Patent Office: Days
• US Class Current: 707/792
• CPC Class Codes: G06F 16/162 Delete operations erasing in storage systems G06F3/0652
• CPC Class Codes: G06F 16/176 Support for shared access to files; File sharing support
• CPC Class Codes: G06F 16/215 Improving data quality; Data cleansing, e.g. de-duplication, removing invalid entries or correcting typographical errors
• CPC Class Codes: G06F 16/907 Retrieval characterised by using metadata, e.g. metadata not derived from the content or metadata generated manually

Abstract

An embodiment of a multi-tenant database system includes a multi-tenant database, an entity definition table, and a data processing engine. The database has objects for multiple tenants, including an existing object for a designated tenant. Each entry in the existing object has a respective entity identifier. The definition table has entries for the database objects, including a metadata entry for the existing object. This metadata entry has a tenant identifier for the designated tenant, an entity name for the existing object, and an old key prefix for the existing object. Each entity identifier of the existing object begins with the old key prefix. The engine performs a data truncation operation on the existing object by updating the metadata entry to replace the old key prefix with a new key prefix. This results in an updated object that is identified by the new key prefix and the tenant identifier.

Claims

1. A computer-implemented method of truncating data from a multi-tenant database that maintains database objects for a plurality of different tenants, each database object in the multi-tenant database being identified by a unique combination of a key prefix and a tenant identifier, the method comprising:

maintaining an entity definition table having a plurality of metadata entries corresponding to the database objects, including a metadata entry for an existing database object, the metadata entry comprising a tenant identifier for a particular tenant associated with the existing database object, an entity name for the existing database object, and an old key prefix for the existing database object;

obtaining an instruction to remove all data from the existing database object; and

in response to obtaining the instruction, updating the metadata entry to replace the old key prefix with a new key prefix that is not currently associated with any other database object for the particular tenant, wherein updating the metadata entry results in an updated database object that is identified by the new key prefix and the tenant identifier.

2. The computer-implemented method of claim 1, wherein updating the metadata entry disassociates previously stored data from the old key prefix.

3. The computer-implemented method of claim 1, further comprising initiating display of a graphical representation of an empty object that corresponds to the updated database object.

4. The computer-implemented method of claim 1, further comprising creating a soft deleted database object that is identified by the old key prefix and the tenant identifier.

5. The computer-implemented method of claim 1, wherein:

each entry in the existing database object is uniquely associated with a respective entity identifier that begins with the old key prefix; and

each entry in the updated database object is uniquely associated with a respective entity identifier that begins with the new key prefix.

6. The computer-implemented method of claim 5, wherein each entry in the multi-tenant database is identified by a unique entity identifier.

7. A computer-implemented method of removing stored data associated with a database object, the method comprising:

assigning a new and previously unused key prefix to an existing database object to disassociate stored data from an old key prefix, resulting in an empty database object that is void of data;

updating a graphical representation of a table to reflect the empty database object; and

presenting the graphical representation of the table to a user.

8. The computer-implemented method of claim 7, further comprising:

creating a soft deleted database object that includes the stored data associated with the old key prefix; and

maintaining the soft deleted database object for a time period after assigning the new and previously unused key prefix to the existing database object.

9. The computer-implemented method of claim 8, further comprising deleting the stored data associated with the old key prefix after the time period ends.

10. The computer-implemented method of claim 8, further comprising deleting the soft deleted database object after the time period ends.

11. The computer-implemented method of claim 7, further comprising repopulating the updated database object with new data.

12. The computer-implemented method of claim 7, wherein:

each entry in the existing database object is uniquely associated with a respective custom entity identifier that begins with the old key prefix; and

each entry in the updated database object is uniquely associated with a respective custom entity identifier that begins with the new and previously unused key prefix.

13. The computer-implemented method of claim 7, wherein:

the existing database object includes a first entry that is linked to a foreign key maintained in a second entry of a target database object, the foreign key stored in a field identified by a first column number; and

the method further comprises altering metadata for the second entry of the target database object by replacing the first column number with a new and previously unused column number, in response to assigning the new and previously unused key prefix to the existing database object.

14. The computer-implemented method of claim 7, wherein:

the existing database object includes a first entry that is linked to a foreign key maintained in a second entry of a target database object; and

the method further comprises removing the second entry of the target database object, in response to assigning the new and previously unused key prefix to the existing database object.

15. The computer-implemented method of claim 7, wherein:

the existing database object includes a first entry that is linked to a summary field value maintained in a second entry of a target database object; and

the method further comprises updating the summary field value in response to assigning the new and previously unused key prefix to the existing database object.

16. The computer-implemented method of claim 7, further comprising maintaining a custom entity definition table having a metadata entry corresponding to the existing database object, wherein:

the metadata entry includes the old key prefix in a key prefix field; and

assigning the new and previously unused key prefix comprises updating the metadata entry to include the new and previously unused key prefix in the key prefix field, to obtain an updated metadata entry that corresponds to the updated database object.

17. The computer-implemented method of claim 7, further comprising:

prior to assigning the new and previously unused key prefix, scanning the key prefixes of the stored data; and

in response to the scanning, determining a candidate key prefix to be used as the new and previously unused key prefix.

18. A multi-tenant database system comprising:

a multi-tenant database comprising one or more database objects for a plurality of tenants, including an existing database object for a designated tenant, wherein each entry in the existing database object is uniquely associated with a respective entity identifier;

an entity definition table having a plurality of metadata entries corresponding to the one or more database objects, and including a metadata entry for the existing database object, the metadata entry comprising a tenant identifier that identifies the designated tenant, an entity name for the existing database object, and an old key prefix for the existing database object, wherein each entity identifier of the existing database object begins with the old key prefix; and

a data processing engine configured to perform a data truncation operation on the existing database object by updating the metadata entry to replace the old key prefix with a new key prefix, wherein updating the metadata entry results in an updated database object that is identified by the new key prefix and the tenant identifier.

19. The multi-tenant database system of claim 18, wherein the data processing engine is configured to create a soft deleted database object that is identified by the old key prefix and the tenant identifier.

20. The multi-tenant database system of claim 19, wherein the data processing engine is configured to delete the soft deleted database object after a designated time period ends.