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Re: Dramatic performance drop when table > 100MB
Posted by: Patrick Questembert
Date: November 02, 2004 04:14PM

Thanks a lot - that was the problem indeed. I had a
PRIMARY KEY (time,msgid)
in my table definition but it turns out this does nothing for queries on msgid (only helps queries on time, or both time and msgid). "EXPLAIN SELECT" showed that quite clearly.

Creating an index for msgid solved the issue completely.

Still wondering why it did work (up to 100MB table size) but that's probably some kind of MySQL optimization for small tables.

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Re: Dramatic performance drop when table > 100MB
November 02, 2004 04:14PM

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