August 7, 2012 at 3:10 pm
hi,
from the index recommendation scripts i ran, the indexes to be created are:
1. on column A
2. on column A include (B,C)
if i only created the second index: A include (B,C)
and my query does not include columns B and C in its select or where clause,
will the query still use this index?
i only want to create one index against column A and i'm trying to understand which index is the superset of which.
thank you
August 7, 2012 at 4:34 pm
sage8 (8/7/2012)
hi,from the index recommendation scripts i ran, the indexes to be created are:
1. on column A
2. on column A include (B,C)
if i only created the second index: A include (B,C)
and my query does not include columns B and C in its select or where clause,
will the query still use this index?
i only want to create one index against column A and i'm trying to understand which index is the superset of which.
thank you
If you only created index 2 a query that only needed column A would be covered, i.e. creating both would be redundant and index 2 would be the superset (sic).
PS corner case disclaimer: just keep in mind index 2 will be larger than index 1 so in rare cases having both could be beneficial to select performance
There are no special teachers of virtue, because virtue is taught by the whole community.
--Plato
August 9, 2012 at 6:15 am
thanks!
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