Hi,

There might be some kind of bug in UPDATE. Let's say there is a 40000 row table, which looks like this:

| fd_01 | int(11) unsigned | | PRI | 0 | | | fd_02 | text | | | | | | fd_03 | varchar(4) | | | | | ... | fd_10 | varchar(20) | | MUL | | | | fd_11 | varchar(20) | | | | |

and indexes are:

| test | 0 | PRIMARY | 1 | fd_01 | A | 40934 | NULL | NULL | | | test | 1 | fd_10 | 1 | fd_10 | A | 40934 | NULL | NULL | |

Now when I do this update: UPDATE test SET fd_11='value' WHERE fd_10='some_value' it usually executes in 0.00 sec

But when the query looks like this: UPDATE test SET fd_11='value' WHERE fd_10=some_value It takes about 2 seconds to execute.

Tested on MySQL 3.23.36 / FreeBSD 4.2 (i386)