… updates this table with a statement like this: UPDATE achievements …UPDATE groups SET last_joined=NOW(), last_user_id=100 WHERE id=1; COMMIT; How often might multiple…Innodb, you might consider relaxing the fsync: set innodb_flush_log_at_trx_commit to something besides 1 and suddenly you can update…
Post: Follow these basics when migrating to Percona XtraDB Cluster for MySQL
May 1, 2013 By 10 Comments
…these basics. log_slave_updates is REQUIRED You need to have log_slave_updates enabled on the …, if you can, you should consider moving to InnoDB altogether. There are very few reasons to stay…planning to write on multiple nodes. Have PRIMARY KEYS If you still have tables without PRIMARY KEYs, then…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…, query id 188161264 localhost root update insert into child values(2,2) Foreign key constraint fails for table `test/child`: , CONSTRAINT `child… if connection is in “Sleep” stage – if it is multiple statement transaction. Innodb also will print OS thread_id and process id… and writes are pending requests on buffer pool level. Innodb may merge multiple requests to one on file level so these are…
Post: MySQL Users Conference - Innodb
May 9, 2007 By 6 Comments
… Auto Increment handling Yet another known Innodb problem is table locks which are taken for statement… about running not-indexed UPDATE which has to lock all rows in Innodb right now) I…mentioned there are more things inside Innodb to unleash performance such as multiple purge threads or parallel…
Post: Innodb Table Locks
July 31, 2012 By 4 Comments
… lock IX is rather lose – I can have multiple update queries running on the table each locking it in IX mode, which will… our update query. We will still see table reported as locked in “IX” in SHOW ENGINE INNODB STATUS while concurrent updates to this table will… MyISAM and Innodb when it comes to Table Level Locks. For MyISAM tables running UPDATE query on the table is essentially equivalent to locking table for…
Post: Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2
May 3, 2011 By 13 Comments
… have multiple dedicated purge threads. Percona Server 5.1 supports multiple purge threads…innodb_doublewrite=1 innodb_flush_method=O_DIRECT innodb_max_dirty_pages_pct=80 innodb_file_format=barracuda innodb_file_per_table max_connections=2000 table… results) and here are the updated 5.6.2 results. The…
Post: Innodb Double Write
August 4, 2006 By 24 Comments
…Innodb will skip page upate operation or “former” in which case Innodb will perform update…Innodb tablespace – it contains space for 100 pages. When Innodb flushes pages from Innodb buffer pool it does so by multiple…
Post: The relationship between Innodb Log checkpointing and dirty Buffer pool pages
February 17, 2012 By 10 Comments
…Innodb updates buffer pool pages in memory and records page operations in the transaction (redo) log. Behind the scenes those updated…multiple times before the page is flushed Multiple rows within the same page can be written before the page is flushed Innodb…
Post: Fix of InnoDB/XtraDB scalability of rollback segment
January 18, 2009 By 9 Comments
…to segment. Fortunately InnoDB internally has mechanism to support multiple rollback segments …table_type=MYISAM innodb_buffer_pool_size=6G innodb_data_file_path=ibdata1:10M:autoextend innodb_file_per_table=1 innodb…-ranges –oltp-index-updates –oltp-non-index-updates –oltp-nontrx-mode select …
Post: Using VIEW to reduce number of tables used
September 28, 2007 By 12 Comments
…tables per server which can become really inefficient. It is especially inefficient with Innodb tables both in terms of space (some tables…table header modification, which is costly. Of course if you can simply rewrite software to store multiple users per table…
