DVP ---- Dathan Vance Pattishall http://www.friendster.com
> -----Original Message----- > From: Homam S.A. [mailto:[EMAIL PROTECTED] > Sent: Wednesday, February 02, 2005 11:50 AM > To: mysql@lists.mysql.com > Subject: Why does dropping indexes takes such a long time? > > I have a non-primary-key index on a large MyISAM table, and > dropping the index takes a long time, in addition to maxing > out the CPU utilization in its final 1/3 interval. > > Why is that Almost all alters causes mysql to rebuild the table. So, it has to remove the binary tree for that key and at the same time it fixes the other keys. As a result it re-builds the table, take a look at your datadir/database look for #sql that is the consistent copy that will get swapped into the true table name. > > In MS SQL Server for example, dropping the index is almost > instantaeous, unless it's clustered and you have other > indexes on the same table, because they have to be rebuilt. > But we're talking here about MyISAM tables with non-clustered indexes. > > This defeats the whole idea of dropping an index on a table > before a large batch update. > > > > > __________________________________ > Do you Yahoo!? > The all-new My Yahoo! - Get yours free! > http://my.yahoo.com > > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: > http://lists.mysql.com/[EMAIL PROTECTED] > > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
