Homam S.A. wrote:
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.
See http://dev.mysql.com/doc/mysql/en/alter-table.html , especially these bits:
"Note that if you use any other option to ALTER TABLE than RENAME, MySQL always creates a temporary table, even if the data wouldn't strictly need to be copied (such as when you change the name of a column). We plan to fix this in the future, but because ALTER TABLE is not a statement that is normally used frequently, this isn't high on our TODO list."
"As of MySQL 4.0, this feature can be activated explicitly. ALTER TABLE ... DISABLE KEYS tells MySQL to stop updating non-unique indexes for a MyISAM table. ALTER TABLE ... ENABLE KEYS then should be used to re-create missing indexes. MySQL does this with a special algorithm that is much faster than inserting keys one by one, so disabling keys before performing bulk insert operations should give a considerable speedup."
You want to DISABLE, not DROP, the keys.
-- Keith Ivey <[EMAIL PROTECTED]> Smokefree DC http://www.smokefreedc.org Washington, DC
-- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
