In the last episode (Jun 16), Jeremy Zawodny said:
> Ah, thanks. The funny thing is that I *did* think to check the source
> code for a different problem I ran into severl minutes later.
> I'll have to poke at this some more. I just restarted with a 64MB
> maximum and one of my more common queries is still "Using
> temporary". I find it difficult to believe that I'm pulling enough
> data to fill a 64MB table. The entire dataset is about 6 times that
> size, and I know I'm not pulling even close to 1/6th of the data.
I think all "Using temporary" means is that mysql has to modify the
result set (i.e. sort or group it) before passing it to the client.
The temp table will stay in RAM unless it gets larger than the
tmp_table_size value, so to tell whether a particular query needed an
on-disk temp table, you'll probably have to compare the
created_tmp_disk_tables stat value before and after the query.