Database system having logical row identifiers

摘要

A database system having logical row identifiers (rowids) includes a secondary index which is traversed to locate a secondary index entry that includes a target secondary key value. Each secondary index entry also includes a logical rowid element. Each logical rowid element has both a primary key value element, and a datablock address element identifying a leaf block in an index-organized table that likely includes a row corresponding to the primary key value element. The leaf block is scanned to locate the row in the index-organized table that includes the target secondary key value and corresponds with the located, secondary index entry. A primary key scan is performed on the index-organized table if the row in the index-organized table is not located in the identified datablock.