I have a linux server which is hosting several very large (~20GB)
databases. In order to save some disk space I dropped an index on one
of the larger (InnoDB) tables because it is no longer needed. It took
about 30 minutes for MySQL to drop the index, during which time I saw
the free disk space decrease. I didn't think anything of it while the
drop operation was running because I figured it was some kind of temp
file being used by the drop (even though the temp directory for mysql
is supposed to be on another partition). To my surprise, after the
index was dropped, not only did I not have more free space as I
expected, but in fact I had about 2 GB less than I did before I
dropped the index. Huh?
So now I'm down 1 index and 2 GB of space. How does dropping a db
object actually increases the amount of disk used by mysql? Is there
anyway I can reclaim this space? MySQL version is 4.0.15
