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.

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