At 01:32 PM 7/20/2007, Andrew Rosolino wrote:
>Whenever I alter a mysql table like add a new field it gets really slow and
>all other processes lag.
>Is there a memory variable I can adjust for this?
It may be slow because if it is rebuilding the indexes to the table. Don't
forget that when you Alter a table, it creates a copy of the table and
after the data is loaded into the new table, the indexes have to be
rebuilt. Run Show ProcessList when the server is running slow to see what
it is actually doing.
If you have a few million rows in the table and lots of indexes, you may
want to increase the size of key_buffer to a few hundred MB if you have the
memory. The upper limit I think on 32 bit machines is 2GB