Managing a multi-version database
Managing different versions of a data record is provided. A mapping is maintained between a version-independent logical record identifier and a version-dependent physical record row identifier that correspond to each data record within a plurality of data records of a data table using a logical record identifier to physical record row identifier indirection mapping table. Entries within leaf pages of an index associated with the data table are updated to point to the version-independent logical record identifier corresponding to a data record instead of pointing to the version-dependent physical record row identifier corresponding to the data record. The logical record identifier to physical record row identifier indirection mapping table is updated in response to performing an operation on the data record instead of updating the entries within the leaf pages of the index associated with the data table.
1. A method for managing different versions of a data record, the method comprising:
maintaining, by a data processing system, a mapping between a version-independent logical record identifier and a version-dependent physical record row identifier that correspond to each data record within a plurality of data records of a data table using a logical record identifier to physical record row identifier indirection mapping table;
updating, by the data processing system, entries within leaf pages of an index associated with the data table to point to the version-independent logical record identifier corresponding to a data record instead of pointing to the version-dependent physical record row identifier corresponding to the data record; and
updating, by the data processing system, the logical record identifier to physical record row identifier indirection mapping table in response to performing an operation on the data record instead of updating the entries within the leaf pages of the index associated with the data table.
2. The method of claim 1 , further comprising:
keeping, by the data processing system, only the version-dependent physical record row identifier that corresponds to a location of a most recent version of the data record within a plurality of versions for the data record in the data table in response to performing the operation on the data record.
3. The method of claim 2 , further comprising:
updating, by the data processing system, the mapping between the version-independent logical record identifier and the version-dependent physical record row identifier that correspond to the data record in the logical record identifier to physical record row identifier indirection mapping table using the version-dependent physical record row identifier corresponding to the location of the most recent version of the data record in the data table in response to performing the operation on the data record.
4. The method of claim 1 , further comprising:
generating, by the data processing system, a null version-dependent physical record row identifier corresponding to the version-independent logical record identifier of the data record within the indirection mapping table without changing the entries within the leaf pages of the index associated with the data table in response to performing a deletion operation on the data record.
5. The method of claim 1 , wherein the physical record row identifier indirection mapping table is stored in a solid-state storage device of the data processing system, and wherein the data table and the index associated with the data table are stored in a magnetic hard disk storage device of the data processing system.
6. The method of claim 1 , wherein the version-independent logical record identifier identifies the data record without identifying a particular version of the data record.
7. The method of claim 1 , wherein the version-dependent physical record row identifier identifies a physical row location where a most recent version of the data record is stored within the data table.
8. The method of claim 1 , wherein the logical record identifier to physical record row identifier indirection mapping table maps one version-independent logical record identifier to one version-dependent physical record row identifier corresponding to the data record.