Multiversion concurrency control for columnar database and mixed OLTP/OLAP workload

• US 20150006466A1
• Filed: 09/03/2013
• Published: 01/01/2015
• Est. Priority Date: 06/27/2013
• Status: Abandoned Application

• Current Assignee: SAP SE
• Original Assignee: SAP SE
• Inventors: Tonder, Andreas, Stephan, Wolfgang, Schreter, Ivan
• Application Number:
  US14/017,063
• Publication Number:
  US 20150006466A1
• Time in Patent Office: Days
• US Class Current: 707/602
• CPC Class Codes: G06F 16/2336 Pessimistic concurrency control approaches, e.g. locking or multiple versions without time stamps

Abstract

Online transactional processing (OLTP) transactions and online analytic processing (OLAP) transactions (e.g., aggregation operations, etc.) are both initiated on at least one table within a columnar oriented insert-only database in which at least a portion of the transactions are executed concurrently. Subsequently, it is checked, for each transaction, whether a corresponding record number is visible for the OLTP transaction using a create baselist bitvector and a delete baselist bitvector for the corresponding table. Thereafter, the OLTP transactions and the OLAP transactions having visible corresponding record numbers are executed. Related apparatus, systems, techniques and articles are also described.

Claims

1. A method comprising:

initiating both online transactional processing (OLTP) transactions and online analytic processing (OLAP) transactions on at least one table within a columnar oriented insert-only database, wherein at least a portion of the transactions are executed concurrently;

checking, for each transaction, whether a corresponding record number within the at least one table is visible for the transaction using a create baselist bitvector and a delete baselist bitvector for the at least one table; and

executing the OLTP transactions and the OLAP transactions having visible corresponding record numbers.

2. A method as in claim 1, wherein the create baselist bitvector and the delete baselist vector respectively comprise a variable number of fixed size chunks comprising vectors of creation timestamps and deletion stamps that are used to determine whether the corresponding record number is visible at an isolation level for the corresponding transaction.

3. A method as in claim 2, further comprising:

executing a garbage collection process moving unconsolidated version information from the chunks to the create baselist bitvector and the delete baselist vector.

4. A method as in claim 3, further comprising:

determining whether the corresponding record number is visible for at least one transaction by iterating through the chunks in the create baselist bitvector and the chunks in the delete baselist bitvector to obtain unconsolidated information and corresponding time stamps.

5. A method as in claim 1, wherein the visibility checking for the transactions are implemented by a transaction manager.

6. A method as in claim 5, further comprising:

calling, for each transaction, the transaction manager to determine whether the corresponding record number is visible at an isolation level associated with the transaction.

7. A method as in claim 1, wherein at least one of the OLAP transactions comprises an aggregation operation.

8. A method as in claim 1, wherein the initiating, checking, and executing are implemented by at least one data processor forming part of at least one computing system.

9. A non-transitory computer program product storing instructions, which when executed by at least one data processor of at least one computing system, result in operations comprising:

initiating both online transactional processing (OLTP) transactions and online analytic processing (OLAP) transactions on at least one table within a columnar oriented insert-only database, wherein at least a portion of the transactions are executed concurrently;

checking, for each transaction, whether a corresponding record number within the at least one table is visible for the transaction using a create baselist bitvector and a delete baselist bitvector for the at least one table; and

executing the OLTP transactions and the OLAP transactions having visible corresponding record numbers.

10. A computer program product as in claim 9, wherein the create baselist bitvector and the delete baselist vector respectively comprise a variable number of fixed size chunks comprising vectors of creation timestamps and deletion stamps that are used to determine whether the corresponding record number is visible at an isolation level for the corresponding transaction.

11. A computer program product as in claim 10, wherein the operations further comprise:

executing a garbage collection process moving unconsolidated version information from the chunks to the create baselist bitvector and the delete baselist vector.

12. A computer program product as in claim 11, wherein the operations further comprise:

determining whether the corresponding record number is visible for at least one transaction by iterating through the chunks in the create baselist bitvector and the chunks in the delete baselist bitvector to obtain unconsolidated information and corresponding time stamps.

13. A computer program product as in claim 9, wherein:

the visibility checking for the transactions are implemented by a transaction manager;

the operations further comprise;

calling, for each transaction, the transaction manager to determine whether the corresponding record number is visible at an isolation level associated with the transaction.

14. A computer program product as in claim 9, wherein at least one of the OLAP transactions comprises an aggregation operation.

15. A system comprising:

at least one data processor; and

memory storing instructions, which when executed by the at least one data processor, result in operations comprising;

initiating both online transactional processing (OLTP) transactions and online analytic processing (OLAP) transactions on at least one table within a columnar oriented insert-only database, wherein at least a portion of the transactions are executed concurrently;

checking, for each transaction, whether a corresponding record number within the at least one table is visible for the transaction using a create baselist bitvector and a delete baselist bitvector for the at least one table; and

executing the OLTP transactions and the OLAP transactions having visible corresponding record numbers.

16. A system as in claim 15, wherein the create baselist bitvector and the delete baselist vector respectively comprise a variable number of fixed size chunks comprising vectors of creation timestamps and deletion stamps that are used to determine whether the corresponding record number is visible at an isolation level for the corresponding transaction.

17. A system as in claim 16, wherein the operations further comprise:

executing a garbage collection process moving unconsolidated version information from the chunks to the create baselist bitvector and the delete baselist vector.

18. A system as in claim 17, wherein the operations further comprise:

determining whether the corresponding record number is visible for at least one transaction by iterating through the chunks in the create baselist bitvector and the chunks in the delete baselist bitvector to obtain unconsolidated information and corresponding time stamps.

19. A system as in claim 15, wherein the visibility checking for the transactions are implemented by a transaction manager.

20. A system as in claim 19, wherein the operations further comprise:

calling, for each transaction, the transaction manager to determine whether the corresponding record number is visible at an isolation level associated with the transaction.