The Bookmark Lookup operator uses a bookmark (row ID or clustering key) to look up the corresponding row in the table or clustered index. The Argument column contains the bookmark label used to look up the row in the table or clustered index. The Argument column also contains the name of the table or clustered index in which the row is looked up. If the WITH PREFETCH clause appears in the Argument column, the query processor has determined that it is optimal to use asynchronous prefetching (read-ahead) when looking up bookmarks in the table or clustered index.

Bookmark Lookup is not used in SQL Server 2005. Instead, Clustered Index Seek and RID Lookup provide bookmark lookup functionality. In SQL Server 2005 Service Pack 2, the Key Lookup operator also provides this functionality.

Graphical execution plan icon

 See Also

Tasks

How to: Display an Actual Execution Plan

Reference

Clustered Index Seek Showplan Operator
RID Lookup Showplan Operator
Key Lookup Showplan Operator

Concepts

Logical and Physical Operators Reference
Displaying Execution Plans by Using the Showplan SET Options (Transact-SQL)

Help and Information

Getting SQL Server 2005 Assistance

 Change History

Release	History
12 December 2006	New content: Added sentence about Key Lookup operator.