…in your system does it mean MyISAM variables are not important ? Not really. You still have some tables in MyISAM format in “mysql…works with MyISAM tables these are MyISAM related. join_buffer_size Buffer used for joins without indexes…
Post: Percona XtraDB Cluster: Failure Scenarios with only 2 nodes
July 25, 2012 By 6 Comments
…_local_index | 1 | | wsrep_ready | ON | only wsrep_local_index…mysql server: [root@percona1 ~]# mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL…does the right thing, this is how it needs to work…not work properly currently, I needed to change it in…why two node clusters is not…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
…in the post. This blog post is not a definitive conclusion about innodb_old_blocks_pct or innodb_old_blocks_time. It does…In MySQL…working…in the buffer pool and the other secondary indexes have been pushed out of the buffer pool. mysql…
Post: Extending Index for Innodb tables can hurt performance in a surprising way
May 22, 2010 By 10 Comments
…indexes on (a) and (a,b) at the same time. This is something what suppose to work but it well often does not…in set (0.00 sec) MySQL Optimizer considers using both (a) and (a,b) indexes and in…
Post: Top 5 Wishes for MySQL
June 29, 2007 By 10 Comments
…why I’m especially interested about it is Sphinx which is currently implemented as storage engine for MySQL but this role does not…in MySQL 5.0 without consistent work with MySQL close Partner – Innobase to ensure Group Commit still works in 5.0 and so we do not…
Post: Connecting orphaned .ibd files
May 13, 2011 By 19 Comments
…why…INDEXES: CREATE TABLE `SYS_INDEXES` ( `TABLE_ID` bigint(20) unsigned NOT NULL default ’0′, `ID` bigint(20) unsigned NOT…in < MySQL-4.0.14 space id the page belongs to (== 0) but in…MySQL 5.1 on CentOS 5.6 x86_64. However it expected to work on all versions of MySQL…
Post: table_cache negative scalability
November 16, 2009 By 23 Comments
… resources (such as memory). With MySQL common sense however does not always works – we’ve seen performance issues … and no indexes and when ran SELECT * FROM tableN in the loop. Each table in such case …Why ? Because for MyISAM tables table header has to be modified each time the table is opened. In…
Post: MySQL: Data Storage or Data Processing
November 18, 2007 By 9 Comments
… faster, though even single node does not take you that far. MySQL concept of Single Query=Single Thread works well when few rows needs… rare case and in most cases it will take much shorter time. This is why we have to do careful indexing build summary… far MySQL does not have anything which tackles this need, even on the roadmap. Indeed MySQL has MySQL Cluster but it is quite different. MySQL Cluster…
Post: The two even more fundamental performance metrics
May 5, 2011 By 6 Comments
…or in scatter plots. It might not seem ….k.a. the index of dispersion, …service time directly. Why would you …in MySQL servers I work with when they’re running a simple read-mostly workload with most data in…does this mean? It means that I need to go back to the customer and ask whether they care But in…
Post: Call for opinions: Do we need MySQL 5.0 with MySQL 5.4 performance
April 29, 2009 By 12 Comments
…MySQL 5.4 release with yet another set of Innodb changes. Why not to include plugin in MySQL…in MySQL 5.4 will this ever going to happen ? Looking at initial benchmarks I’m very impressed with Sun Performance Team work…
