Hi

You talking SQL Server? if so, the bookmark lookup op is performed when:
a) a scan of a heap must do a further lookup over its corresponding
clustered index to get the rest of the row data
b) a query cannot be sufficed in terms of data returned by any of its
indexes (such as covering indexes), resulting in a bookmark lookup to the
underlying data page.

As for a technical explanation of the OP itself, check MSDN, they have
lengthly white papers on this topic.

cheers

ck


-----Original Message-----
From: Thiagarajan Gopalakrishnan
[mailto:Thiagarajan.[Email Address Removed] Wednesday, 20 November 2002 3:03 PM
To: LazyDBA.com Discussion
Subject: What is Bookmark LookUp in Query Execution Plan,


Hi
Could you please get me what, where and why Bookmark Lookup is performed
during Query Execution.

Thanks and Regards

PG Thiagarajan


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