"Homam S.A." <[EMAIL PROTECTED]> wrote on 01/28/2005 02:27:51 PM:
> Dropping an index on a MyISAM table should be > instantaneous. It should only take as long as deleting > the idx file from the file system. But it's taking > almost as long as creating the index itself! > > Here's my queries and time they took: > > /*[10:58:17 AM][367172 ms]*/ alter table MyTable add > index (MyIndex) > > /*[11:20:21 AM][183891 ms]*/ alter table MyTable drop > index MyIndex > > In MS SQL server, if the index isn't clustered and > there are no other indexes in the table, dropping the > index is instantaneous. > > This extreme slowness in dropping a simple index in > MySQL defeats the whole strategy of dropping indexes > on some tables before a huge insert operation. > > Why doesn't it just delete the index file and clear > whatever cached buffers it has of it? > > You neglected to mention which version of MySQL you are running. This behavior may have been fixed in newer versions as yours is not the first post I can remember seeing on this general topic. Shawn Green Database Administrator Unimin Corporation - Spruce Pine
