Re: failed queries of large tables with error mysqld got signal 11

[Peter Brawley]

I think you'll get better performance if the key is on the grouping keys. Without that, Explain Extended says ...

Using where; Using Where;, Using temporary; Using filesort

With it, it says Using where, using index---much better.

Try it with and without the amount. Also try with Decimal instead of Float. Do this ...

SET LOCAL query_cache_type = 0;
SET GLOBAL query_cache_size = 0;
RESET QUERY CACHE;

then benchmark with 70K rows, run explain extended with the various keys, then benchmark 700k rows with decimal vs float to see if it makes a diff.