Re: Index suggestion needed for performance improvement
Posted by:
Rick James
Date: October 04, 2015 01:22PM
> also is there any drawbacks if i create too many indexes ?
Yes, but generally the drawbacks are outweighed by the benefits.
Drawbacks (all minor):
* More work on INSERT (especially for UNIQUE).
* If you UPDATE a column that is in an index, a 'row' must be deleted from one spot in the index and re-inserted in another spot.
* The Optimizer considers all indexes, so is slowed down.
* You are likely to be adding indexes that will never be used. (I don't see any 'redundant' indexes in your table now.)
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