> > That throws out my first theory about table locks. That's what I thought, too.
> What do vmstat and top say? Is it CPU bound? I/O bound? Certainly not CPU bound. Maybe I/O bound, not conclusive. My current theory is that there is some thrashing on key buffer blocks. > > Also you might want to do a "show status" before and after. Before and after the short query? | Handler_commit | 0 | | Handler_delete | 20075144 | | Handler_read_first | 18 | | Handler_read_key | 432092430 | | Handler_read_next | 510230999 | | Handler_read_prev | 0 | | Handler_read_rnd | 148798998 | | Handler_read_rnd_next | 1676270985 | | Handler_rollback | 0 | | Handler_update | 122968312 | | Handler_write | 286299142 | ... | Key_blocks_used | 2887383 | | Key_read_requests | 2929797981 | | Key_reads | 8856159 | | Key_write_requests | 305442125 | | Key_writes | 94187694 | | Uptime | 268069 | | Handler_commit | 0 | | Handler_delete | 20075144 | | Handler_read_first | 18 | | Handler_read_key | 432092430 | | Handler_read_next | 510230999 | | Handler_read_prev | 0 | | Handler_read_rnd | 148798998 | | Handler_read_rnd_next | 1676280460 | | Handler_rollback | 0 | | Handler_update | 122968312 | | Handler_write | 286308623 | ... | Key_blocks_used | 2887383 | | Key_read_requests | 2929979657 | | Key_reads | 8859748 | | Key_write_requests | 305476828 | | Key_writes | 94187704 | | Uptime | 268102 | OK, so in 33 seconds, it did 181676 read requests and 3589 reads, and 34703 write requests and 10 actual writes. 108 reads/sec, less than 1 write/sec. systat vmstat tells me that the overall data rate off the index disk is relatively low, but the disk is pretty busy, so there's a lot of seeking. The data disk is barely being touched. > You might want to try putting the result of both "show status" calls > side by side to see if some unexpected resource is being used. Nothing jumps out at me. Handler_read_rnd_next is increasing at 287/sec, which isn't small... The key_buffer is 3GB or 4GB on this system. I'm contemplating an upgrade to 4.1 so I can have multiples. Thanks for looking at this... -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
