…MySQL 5.5 MySQL 5.6 MySQL 5.6 w/ join_buffer_size=6M & read_rnd_buffer_size=6M MariaDB 5.5 MariaDB 5.5 w/ join_buffer_size=6M & mrr_buffer_size… join_buffer_size and the read_rnd_buffer_size/mrr_buffer_size and both of these buffers should be increased appropriately for the best possible performance…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…buffer_size, while MariaDB introduces a different variable to control the MRR buffer size mrr_buffer_size. Both buffer sizes default to 256K in MySQL…buffer size is set large enough so that the index tuples fit in the buffer. But there is no performance…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…MySQL ….commanual join_buffer_sizeblogpercona….Performance_schema_mutex_classes_lostblogpercona.commanual Performance_schema_mutex_instances_lostblogpercona.commanual Performance_schema_rwlock_classes_lostblogpercona.commanual Performance_schema_rwlock_instances_lostblogpercona.commanual Performance…
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
…perform on each database. To do the size comparison, I used the du utility: InnoDB file size…mysql-inno.sock [mysqld] socket=/tmp/mysql-inno.sock default-storage-engine=INNODB innodb-buffer-pool-instances=2 innodb-buffer-pool-size…-io-threads=4 join-buffer-size=16M key-buffer-size=64M local-infile=…
Post: MySQL Server Variables - SQL layer or Storage Engine specific.
June 8, 2006 By 14 Comments
MySQL Server has tons of variables which may be adjusted to change behavior or for performance purposes. They are documented in the… currently works with MyISAM tables these are MyISAM related. join_buffer_size Buffer used for joins without indexes and few other cases. It is used…
Post: Side load may massively impact your MySQL Performance
November 13, 2011 By 7 Comments
… about MySQL interactive performance -…buffer pool contents. mysql [localhost] {msandbox} (information_schema) > select concat_ws(‘.’, t.schema, t.name, i.name) as index_name, sum(data_size…size_mb from innodb_sys_tables as t inner join innodb_sys_indexes as i using(table_id) inner join innodb_buffer…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 139 Comments
… sets are Buffers, Indexes and Joins. Buffers First thing …size and expect gradual performance decrease as database size grows you may be surprised by serve drop in performance…performance implications designing the system and do not expect joins to be be free. Finally I should mention one more MySQL…
Post: Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit
November 24, 2011 By 2 Comments
…A speculative processor might perform the read first,… inside a block of size 800000 alloc’d ==9090== … spin stats join the company of the buffer pool and I…JOIN*, enum_schema_table_state) (sql_show.cc:6238) ==9090== by 0x6A5E0C: JOIN::exec() (sql_select.cc:1863) ==9090== by 0x6A7D72: mysql…
Post: Innodb Performance Optimization Basics
November 1, 2007 By 70 Comments
…out MySQL out of memory. MySQL Innodb Settings The most important ones are: innodb_buffer_pool_size 70-…between reasonable recovery time and good performance innodb_log_buffer_size=4M 4M is good for most…in joins), large unpacked indexes (try to be easy on indexes). With these basic innodb performance…
Post: Scaling problems still exist in MySQL 5.5 and Percona Server 5.5
May 20, 2011 By 11 Comments
…id,deleted) This pattern of medium size IN lists is typical for… configured with innodb_buffer_pool_instances=16 and 400GB buffer pool. Here are… shows from performance at 1 thread to the peak performance we see …,JOIN::exec,mysql_sel ect,handle_select,execute_sqlcom_select,mysql_execute_command,mysql_…
