SAP SE
Existence checks on rows within a database

Abstract:

Example methods and systems are directed to existence checks on rows within a database. A page data structure stores bitmap data for the rows in the page. A row within the page corresponds to a single bit in the bitmap data. To determine if a row has been deleted, the page data structure for the page containing the row is located and the bit for the row in the page data structure is checked. An array of page data structures is created, indexed by a hash of the page identifier. In the event of a hash collision, a linked list of page data structures is used, sorted by page identifier.