Note that in many (too many) cases, _all_ partitions are opened, even if only one is really needed.
> -----Original Message----- > From: louis liu [mailto:yloui...@gmail.com] > Sent: Monday, May 14, 2012 7:02 AM > To: Johan De Meersman > Cc: mysql@lists.mysql.com; Rick James > Subject: Re: drop partitions > > not actually , first partition to have been dropped is no longer in > use > ,we dropped partition from old -> new > > > > > 2012/5/14 Johan De Meersman <vegiv...@tuxera.be> > > > ----- Original Message ----- > > > From: "Rick James" <rja...@yahoo-inc.com> > > > > > > If you have 14 partitions in each of 390 tables, and if you have > > > most of the tables 'active', then you are possibly thrashing in the > > > table_open_cache. > > > > A distinct possibility. > > > > > Compute (SHOW STATUS): > > > Opened_tables / Uptime -- don't want more than a few per sec. > > > Opened_files / Uptime -- ditto > > > Opened_table_definitions / Uptime -- ditto > > > > Assuming you have anywhere near decent uptime, those are going to be > > way too flattened to be of use. Trend monitoring is a necessity - > look > > at Munin or Cacti. > > > > > > A random thought, though - could the first partition to have been > > dropped not have been in active use, so the drop operation had to > wait > > for all other statements to end, and the other (older?) partitions no > > longer in use, so could be dropped immediately? > > > > > > -- > > Bier met grenadyn > > Is als mosterd by den wyn > > Sy die't drinkt, is eene kwezel > > Hy die't drinkt, is ras een ezel > > > > > > -- > Phone: +86 13918046970 > Email & Gtalk: yloui...@gmail.com > Personal Blog: http://www.vmcd.org -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
