Indexes :-

hi,
one small ques on indexes, i added one composite index on table to avoud clus index scan(cost 70%) , when i checked executioin plan it is showing me like clus index seek using the above defined index + bookmark lookup operator also..
so which soln should i go for clus index scan or bookmark operator using clus index seek (for composit index0
--
SanjuRun the query both ways in Query Analyzer and look at the Total Plan cost
... use whichever is cheaper..
I suspect if you are returning more than (maybe) 5% of the rows in the table
the clustered index scan might be cheaper...
However it does depend on the percentage of the rows returned, a single or
very small number of rows returned will likely be best served by the
nonclust and bookmark lookup, a larger percentage of rows and the clustered
index scan will be faster...
--
Wayne Snyder, MCDBA, SQL Server MVP
Mariner, Charlotte, NC
www.mariner-usa.com
(Please respond only to the newsgroups.)
I support the Professional Association of SQL Server (PASS) and it's
community of SQL Server professionals.
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"Sanjay" <Sanjay@.discussions.microsoft.com> wrote in message
news:B0F41810-3BC3-4D2C-9996-7D08C46F614D@.microsoft.com...
> hi,
> one small ques on indexes, i added one composite index on table to avoud
clus index scan(cost 70%) , when i checked executioin plan it is showing me
like clus index seek using the above defined index + bookmark lookup
operator also..
> so which soln should i go for clus index scan or bookmark operator using
clus index seek (for composit index0
> --
> Sanju