July 17, 2009 at 8:32 am
i found many missing indexes, so what's the next step should i do. or should i rebuild or what else should i do.
July 17, 2009 at 9:10 am
I think that missing indexes coming from DMV are just a hint to report something can be improved, but I would never create the indexes exactly how the DMV suggests. I would rather investigate existing indexes and IO stats to determine whether a new index is the right way to go.
If the tables involved are more frequently written than read, be careful when applying new indexes: more indexes = faster reads but slower writes.
In other words: there's no "magic wand", you'd rather do it by hand.
Hope this helps
Gianluca
-- Gianluca Sartori
July 17, 2009 at 10:43 am
You can use the information from the missing indexes DMV as a starting point for tuning. You need to carefully assess the recommendations though because they're frequently weak. I've seen it recommend an index for Col1 and another index for Col1, Col2 and a third index for Col1, Col2, Col3. The fact is, if you really needed an index, it should be the last one because it's the same as the first two.
Careful investigation and testing of all the suggestions are the plan you should follow.
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
- Theodore Roosevelt
Author of:
SQL Server Execution Plans
SQL Server Query Performance Tuning
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