… after restoring table from mysqldump, the query that scans data by primary key was slow. How slow ? Let me show. The query in question is… | 35904 | +——————————+——-+ 2 rows in set (0.00 sec) As for mysqldump you may use –order-by-primary options to force dump…
Post: Percona Server 5.5.16-22.0
October 16, 2011 By 2 Comments
…executed. #857590 (Alexey Kopytov). QUERY_RESPONSE_TIME doesn’t respect QUERY_RESPONSE_TIME_STATS . #855312 (Oleg Tsarev). The mysqldump option –innodb-optimize-…Alexey Kopytov). The Slow Query Log did not log the error number correctly. #830199 (Oleg Tsarev). Variable log-slow-admin-statements was …
Post: Performance impact of complex queries
January 17, 2007 By 11 Comments
… 2.4 times I could make single full table scan query to slow things that bad, so “ls” would take over 10… the slave and when move them to the master using mysqldump, or even careful file transfer if you’re using MyISAM… the load is low enough so your complex query or batch job do not slow things to bad. In some environments which…
Comment: Database problems in MySQL/PHP Applications
November 6, 2006 By 12 Comments
…=2048 long-query-time=5 log-slow-queries=/apps/log/slow-query interactive_timeout=300 wait_timeout=300 thread_cache = 40 max_connections=500 query_cache…_log_at_trx_commit = 1 #innodb_lock_wait_timeout = 50 [mysqldump] quick max_allowed_packet = 16M [mysql] no-auto-rehash # Remove…
Post: Side load may massively impact your MySQL Performance
November 13, 2011 By 7 Comments
… is drastically impacted when some heavy queries are ran in background or backup is done with mysqldump – a lot more than you… table drops more than 150 times when heavy mysqldump is running concurrently. mysqldump itself also slows down about 2x. What is going on… “young” sublist. However when you’re doing mysqldump (or running some complex batch job query) you are likely going to have multiple…
Post: Improved InnoDB fast index creation
November 6, 2011 By 4 Comments
… | 0.000007 | | Waiting for query cache lock | 0.000002 | | end | 0.000007 | | query end | 0.000003 | | closing… will not be affected by a slow tmpdir, but rebuilding the indexes will … in my previous examples): $ mysqldump -uroot test > dump_unoptimized.sql $ mysqldump -uroot test –innodb-optimize…
Post: Living with backups
November 6, 2008 By 28 Comments
…€™s more like doing very heavy queries against each table in the database when mysqldump is used or reading a lot of… is being filled with random information additional I/O occur slowing everything down even further. What does it all mean? There… to the incoming queries quick enough. What can be done about it? Nothing really when you are using mysqldump. You can play…
Comment: Using LVM for MySQL Backup and Replication Setup
August 18, 2011 By 53 Comments
… situation that our analytics teams issues heavy raw mysql queries that run for hours in some cases days on … goes for a toss and that causes slave to slow down and not sync up with the master . Now … volume group they are residing in , now taking a mysqldump is a long process and can’t afford the …
Post: Should you move from MyISAM to Innodb ?
January 12, 2009 By 53 Comments
…a dedicated slave available for all long reporting queries. In case MyISAM was chosen not just happened…, problems dealing with very large number of tables, slow data load and ALTER TABLE and others. …affects Operations aspects a lot – for example using mysqldump as a backup may well work for MyISAM…
Post: Detailed review of Tokutek storage engine
April 28, 2009 By 21 Comments
…not good results for some kind of queries, i.e. point select queries, as in this case TokuDB has …release soon. – The ways to do a backup is mysqldump/mysqlhotcopy. It is not fully transparent backup, as … of random IO, waste of RAM memory and slow inserts. This is where I think Tokutek appears …
