At 12:43 AM 7/9/2010, you wrote:
On Fri, Jul 9, 2010 at 7:30 AM, Neil Tompkins
<neil.tompk...@googlemail.com>wrote:
>
> Should we be looking to create a index for all fields that we might be
> perform a select condition in a where clause for ?
Neil,
Keep in mind that the more indexes you add to a table, the slower
your inserts will become because it needs to maintain the indexes. I would
only consider adding indexes to the slow queries. You can use the Explain
on your Select statement to see which indexes are being used. See
http://www.databasejournal.com/features/mysql/article.php/1382791/Optimizing-MySQL-Queries-and-Indexes.htm
for an explanation on how to use EXPLAIN.
BTW, if you are indexing text columns, you may want to look at FullText
indexing.
Mike
It's a bit of trial and error, you have to weight the number of times you
select based on a potential index vs. the impact that index might have for
the amount of updates you do on the table.
Generally speaking, though, it's indeed a good idea to find the
most-frequently used where-clauses and index them.
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