Patent ID: 9268810
Filing Date: 2016-02-23
CPC Classification: G06F

Claim Text:
1. A method for providing a locking mechanism in a database system to support transaction processing, comprising: establishing a column-based in-memory database including a main store and a delta store, wherein the main store allows non-concurrent transactions on a same table and the delta store has a plurality of row-visibility bitmaps implementing a row-level versioning mechanism that allows concurrent transactions on the same table; executing within a transaction a delete or an update statement on a table having plurality of table versions which provide transaction-consistent snapshots of the table visible to the transaction at various points in time, wherein the table versions are represented by bitmaps in the delta store and the bitmaps corresponding to the table versions implement row identifier (RID) spaces for the table; requesting a lock on a row of the table manipulated by the delete or the update statement to preclude other transaction from deleting or updating an obsolete version of data; validating the row so that the row to be locked is not the obsolete version in the RID spaces of the table; and granting a lock to the transaction upon a successful validation of the row.