Archiving objects in a database environment

Patent metadata

Field	Value
Publication number	US-11068448-B2
Application number	US-201916241810-A
Country	US
Kind code	B2
Filing date	Jan 7, 2019
Priority date	Jan 7, 2019
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

A method is provided for processing a query. In some embodiments, the method includes creating a historical schema defining an ordered set of fields based on a current schema of an object and a field modification of the current schema. The method includes inserting, based on the field modification, a new field at an end of the historical schema and archiving records into a second storage device. The method includes receiving a query, which includes a command specifying a subset of fields and which indicates a non-current field. The method includes searching in the second storage device for archive records having a second schema including the subset of fields and the non-current field. The first and second schemas follow the field order in accordance with the historical schema. The method further includes accessing the subset of fields and the non-current field in accordance with the command.

First claim

What is claimed is:

1. A computing device comprising:
a memory containing machine readable medium storing machine executable code; and
one or more processors coupled to the memory and configurable to execute the machine executable code to cause the one or more processors to:
create a historical schema defining an ordered set of fields based on a current schema of an object and a field modification of the current schema;
insert, based on the field modification, a new field at an end of the historical schema;
archive a plurality of records stored in a first storage device into a second storage device, each record of the plurality of records being based on the object and corresponding to an archive record having a first schema common to the respective record at a time of archive, and the first schema following a field order in accordance with the historical schema;
receive a query including a command specifying a subset of fields based on the object, the query indicating a non-current field absent from the current schema;
search in the second storage device for a set of archive records having a second schema including the subset of fields and the non-current field, the second schema following the field order in accordance with the historical schema; and
access the subset of fields and the non-current field in accordance with the command.

2. The computing device of claim 1 , wherein the field modification includes a modification of a field, the field modification including at least one of an addition of the field to the object, a modification of a definition of the field, or removal of the field from the object.

3. The computing device of claim 1 , wherein the machine executable code further causes the one or more processors to:
snapshot the current schema of the object, wherein the historical schema includes the snapshot and at least one new field inserted at the end of the historical schema.

4. The computing device of claim 1 , wherein the machine executable code further causes the one or more processors to:
search metadata corresponding to the object for the second schema including the subset of fields; and
identify a schema identifier (ID) that identifies the second schema, the set of archive records including the schema ID.

5. The computing device of claim 4 , wherein the metadata includes one or more entries, each entry including a given schema ID assigned to a given schema, the given schema, and a timestamp corresponding to a given time at which at least one archive record defined by the given schema was archived.

6. The computing device of claim 1 , wherein the query includes a backdoor field that maps to the non-current field, and wherein the current schema and the historical schema are devoid of the backdoor field.

7. The computing device of claim 6 , wherein the machine executable code further causes the one or more processors to:
access a set of fields specified in the current schema in accordance with the command, wherein the backdoor field maps to the current schema of the object.

8. The computing device of claim 1 , wherein the query includes the non-current field.

9. The computing device of claim 1 , wherein the machine executable code further causes the one or more processors to:
create a second historical schema defining a second ordered set of fields based on a second current schema and a second field modification of the second current schema, the first historical schema and the first current schema being based on a first tenant's version of the object, and the second historical schema and the second current schema being based on a second tenant's version of the object.

10. The computing device of claim 9 , wherein the first and second schemas include a common set of standard fields.

11. The computing device of claim 9 , wherein the machine executable code further causes the one or more processors to:
insert, based on the second field modification, a second new field at an end of the second historical schema;
archive a second plurality of records stored in the first storage device into the second storage device, each record of the second plurality of records being based on the second tenant's version of the object and corresponding to an archive record having a third schema common to the respective record at a time of archive, and the third schema following a second field order in accordance with the second historical schema;
receive a second query including a second command specifying a second subset of fields based on the second tenant's version of the object, the second query indicating a second non-current field absent from the second current schema;
search in the second storage device for a second set of archive records having a fourth schema including the second subset of fields and the second non-current field, the fourth schema following the second field order in accordance with the second historical schema; and
access the second subset of fields and the second non-current field in accordance with the second command.

12. A method performed by one or more processors executing machine executable code, the method comprising:
creating a historical schema defining an ordered set of fields based on a current schema of an object and a field modification of the current schema;
inserting, based on the field modification, a new field at an end of the historical schema;
archiving a plurality of records stored in a first storage device into a second storage device, each record of the plurality of records being based on the object and corresponding to an archive record having a first schema common to the respective record at a time of archive, and the first schema following a field order in accordance with the historical schema;
receiving a query including a command specifying a subset of fields based on the object, the query indicating a non-current field absent from the current schema;
searching in the second storage device for a set of archive records having a second schema including the subset of fields and the non-current field, the second schema following the field order in accordance with the historical schema; and
accessing the subset of fields and the non-current field in accordance with the command.

13. The method of claim 12 , wherein at least one archive record corresponding to an original record of the plurality of records includes a full record containing values from the original record.

14. The method of claim 13 , wherein the full record contains a serialized immutable archive record storing the values.

15. The method of claim 13 , wherein the full record is stored in a field of the archive record.

16. The method of claim 12 , wherein the query includes a backdoor field that maps to the non-current field, the method further comprising:
searching metadata corresponding to the object for a candidate schema including the subset of fields and one or more non-current fields of the object.

17. The method of claim 12 , wherein the query includes the non-current field.

18. The method of claim 12 , further comprising:
creating a second historical schema defining a second ordered set of fields based on a second current schema and a second field modification of the second current schema, the first historical schema and the first current schema being based on a first tenant's version of the object, and the second historical schema and the second current schema being based on a second tenant's version of the object.

19. The method of claim 18 , further comprising:
inserting, based on the se

Assignees

• Salesforce Com Inc

Inventors

• Fernando Jan Asita
• Jain Samarpan
• Davidchuk Matthew
• Annamalai Natarajan Valliappan
• Syomichev Alexey
• Marcel Cody
• Kalvala Seshank
• Ramrakhyani Sahil
• Hersans Alexandre

Classifications

• G06F16/213 Primary

  with details for schema evolution support · CPC title

• G06F16/28

  Databases characterised by their database models, e.g. relational or object models · CPC title

• G06F16/211 Primary

  Schema design and management · CPC title

• G06F16/24

  Querying · CPC title

• G06F16/245

  Query processing · CPC title