… innodb_table_monitor (a INT) ENGINE=INNODB; This, primitively, tells Innodb that it should start the Table monitor. The monitor itself dumps the contents of the Data dictionary to the mysql error log, which looks something like this: =========================================== 090420 12:09:32 INNODB TABLE…
Post: Announcing Percona XtraDB Storage Engine: a Drop-in Replacement for Standard InnoDB
December 16, 2008 By 25 Comments
… fixed problems with lock information. documentation Improvements to InnoDB IO. Improvements of InnoDB IO subsystem, such as multiple read and write threads… pool fixes Improvements of buffer_pool scalability. documentation innodb_buffer_pool_pages Information about content of buffer_pool pages. documentation Documentation is…
Post: Innodb Double Write
August 4, 2006 By 24 Comments
One of very interesting techniques Innodb uses is technique called “doublewrite” It means Innodb will write data twice when it performs table… term log file allocated inside Innodb tablespace – it contains space for 100 pages. When Innodb flushes pages from Innodb buffer pool it does… fsync() called the second time. Now on recovery Innodb checks doublewrite buffer contents and pages in their original location. If page is…
Post: Innodb Recovery Update - The tricks what failed.
May 24, 2007 By 3 Comments
… data and find some other way to recovery. Examining Innodb page content and crash information we figured out it should be page… no way to make Innodb avoid touching it. Even when we dropped all Innodb tables (for test purposes) Innodb still was crashing if… faulty hardware. Primary keys are typically simple integer keys in Innodb while secondary keys may have very complex structure. Compex corruptions…
Post: Innodb row size limitation
April 7, 2011 By 12 Comments
…, fcopyright TEXT, fstylesheet TEXT, fterms TEXT, PRIMARY KEY (id) ) Engine=InnoDB; Now you insert some test data into it: mysql> INSERT… Â ‘First title’, ->Â Â ‘First subtitle’, ->Â Â ‘First content‘, ->Â Â ‘First header’, ->Â Â ‘First footer’, ->Â Â… http://www.mysqlperformanceblog.com/2010/02/09/blob-storage-in-innodb/ for further reference). It’s worth mentioning that this limit…
Post: Analyzing the distribution of InnoDB log file writes
July 16, 2010 By 5 Comments
… of its performance implications here. How many big writes does InnoDB do, and how many small writes? First, I found out… size wouldn’t be good and could cause additional lock contention. (There is a single mutex around the log buffer.) We… this up with some more benchmarks or observations under different InnoDB settings and different workloads. Or then again, maybe Yasufumi will…
Post: Index lock and adaptive search - next two biggest InnoDB problems
February 25, 2010 By 12 Comments
… constantly face two contention problems. So I suspect it’s going to be next biggest issues to make InnoDB scaling on high… key select queries and write queries at the same time. InnoDB again uses single global mutex for adaptive_search (single mutex… variable), but it rarely helps actually. With disabled adaptive index InnoDB needs to perform much more operations reading secondary keys. How…
Post: Few more ideas for InnoDB features
June 29, 2009 By 7 Comments
… MySQL is doing great in InnoDB performance improvements, so we decided to concentrate more on additional InnoDB features, which will make difference…/03/30/my-hot-list-for-next-innodb-features/ (and one of them – moving InnoDB tables between servers are currently under development… different tables in different buffer pools and also to decrease contention on buffer pool. Link https://blueprints.launchpad.net/percona-patches…
Post: thread_concurrency doesn't do what you expect
June 4, 2012 By 3 Comments
… concurrently you should read about innodb_thread_concurrency: http://www.mysqlperformanceblog.com/2011/07/28/how-innodb-contention-may-manifest-itself/ http://www…-throughput/ http://www.mysqlperformanceblog.com/2010/05/24/tuning-innodb-concurrency-tickets/ innodb_thread_concurrency places a limit on the number of…
Post: Join performance of MyISAM and Innodb
May 29, 2006 By 6 Comments
… today which involved benchmarks of Join speed for MyISAM and Innodb storage engines for CPU bound workload, this is when data… data is clustered together with index and generally highly optimized Innodb builds hash indexes which helps to speed up lookup by… index Note: This applies to CPU bound workload with all content fitting in memory. In other cases situation is very different…
