… with very large data sets are Buffers, Indexes and Joins. Buffers First thing you need to take … benefit from using indexes. In fact even MySQL optimizer currently does not take it into account. … disaster. The problem is not the data size – normalized data normally becomes smaller, but dramatically …
Post: MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
…can get extra optimizations by optimizer knowing index is UNIQUE the drawback is insert buffer will not be able…to join the two tables? A: The question in this case is how MySQL will execute the join. If…portions of them which are accessed frequently. The size of this “working set” can greatly depend …
Post: Innodb Performance Optimization Basics
November 1, 2007 By 75 Comments
…OS And Application optimization. I call this Innodb Performance Optimization Basics so…MySQL out of memory. MySQL Innodb Settings The most important ones are: innodb_buffer_pool_size…and good performance innodb_log_buffer_size=4M 4M is good for… (try to use it in joins), large unpacked indexes (try to …
Comment: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
….com/supportingmysql/entry/server_defaults_changes_in_mysql , in documentation now at http://dev.mysql.com/doc/refman/5.6/en/server… startup. join_buffer_size is bigger to help queries that don’t use indexes and that do use some of the new optimizer features… of more costly queries and/or low query rates. sort_buffer_size is much improved over the past 2M but still a…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
…buffer pool in pages afterwards: mysql> select sq.*, pages / (@@innodb_buffer_pool_size / 16384) * 100 pct_buffer…joining the tables in the other direction mysql> select straight_join sum(lo_extendedprice*lo_discount) as revenue from dim_date join… | 0 | 3 | 3 | | 8 | optimizing | 0.000048 | 0.000048 …
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…InnoDB 500 mysql tables in use 1, locked 1 3 lock struct(s), heap size 320 MySQL thread id…be “waiting in InnoDB queue” or “sleeping before joining InnoDB queue”. Latest one is quite interesting – …if your innodb_log_buffer_size is optimal – if you see more than 30% of log buffer size being unflushed …
Comment: MySQL Server Memory Usage
September 1, 2006 By 21 Comments
…’Com_lock_tables’, ’102′ ‘Com_optimize‘, ’0′ ‘Com_preload_keys’, ’0′…_status’, ‘NULL’ ‘Select_full_join‘, ’0′ ‘Select_full_range_join‘, ’0′ ‘Select_range’,…buffer_pool_size=1800M # USE ALL MEMORY AVAILABLE #innodb_log_buffer_size=8M # Lowered from 32M according to MySQL innodb_additional_mem_pool_size…
Post: How well does your table fits in innodb buffer pool ?
December 9, 2010 By 12 Comments
…other queries. MySQL Server …size, 2) fit_pct FROM (SELECT index_id, COUNT(*) cnt, SUM(dirty = 1) dirty, SUM(hashed = 1) hashed FROM innodb_buffer_pool_pages_index GROUP BY index_id) bp JOIN innodb_sys_indexes ON id = index_id JOIN…buffer pool is affected by batch jobs, alter tables, optimize…
Post: Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
…optimizations or troubleshooting the applications. We ourselves often rely on it when doing commercial MySQL consulting and MySQL…buffer-size=4 -m64 -mtune=generic’ ‘CXXFLAGS=-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector –param=ssp-buffer-size…_scan, full_join, tmp_table,…
Post: Join performance of MyISAM and Innodb
May 29, 2006 By 6 Comments
…, this is when data size is small enough to fit in memory and so buffer pool. I tested …primary key joins are very fast as data is clustered together with index and generally highly optimized Innodb builds … the index, so there is no need for MySQL to request next row matching index Note: This …
