… join rows with table t2. This step is called the build step. After the hash table has been created, rows from table t2 are… a look at the status counters. Counter Name MySQL 5.5 MySQL 5.6 MySQL 5.6 w/ join_buffer_size=6M & read…_buffer_size=4M & mrr_buffer_size=4M Created_tmp_disk_tables 0 0 0 0 0 0 Created_tmp_tables 1 1 1 1 1 1 Handler…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
… that the disks are 4 5.4K disks in Software RAID5. Also note that the following changes were made in the MySQL config….6 MySQL 5.6 w/ read_rnd_bufer_size=4M MariaDB 5.5 MariaDB 5.5 w/ mrr_buffer_size=4M Created_tmp_disk_tables 1 1 1 1 1 Created_tmp_tables 1 1 1 1 1 Handler_mrr_init…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a… optimizer enhancement Index Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take…
Post: How to diagnose errors in the MySQL error log
March 26, 2012 By 4 Comments
…:56:45 [ERROR] /usr/sbin/mysqld: Incorrect key file for table ‘/tmp/#sql_21b2_0.MYI’; try to repair it 120326 16… writing file ‘/tmp/MYK74Kpi’ (Errcode: 28) The gem in all of that mess is this bit: (Errcode: 28). Now, MySQL includes a… to understanding what really happened. MySQL created a temporary table, using the MyISAM storage engine, and when the disk filled up, MyISAM got an…
Post: Finding what Created_tmp_disk_tables with log_slow_filter
September 22, 2008 By 3 Comments
… noticed a large number of temporary tables being created on disk. show global status like ‘Created_tmp%’ | Created_tmp_disk_tables | 91970 | | Created_tmp_files | 19624 | | Created_tmp_tables | 1617031 | Looking at a 60… queries creating disk based tables. mysqladmin ext -ri60 | Created_tmp_disk_tables | 74 | | Created_tmp_files | 3 | | Created_tmp_tables | 357 | Luckily this client was running the Percona patched version of MySQL. The…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…to the amazing MySQL manual, especially the option and variable reference table. But just as….commanual core_fileblogpercona.commanual Created_tmp_disk_tablesblogpercona.commanual Created_tmp_filesblogpercona.commanual Created_tmp_tablesblogpercona.commanual datadirblogpercona.commanual …
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
…Tmp_tables: 0 Tmp_disk_tables: 0 Tmp_table_sizes: 0 # InnoDB_trx_id: F00 # QC_Hit: No Full_scan: Yes Full_join: No Tmp_table: No Tmp_table_on_disk…tables involved and the query execution plan used by MySQL….tmp_tbl_size variable is set to 32M on the server, so on-disk tables are probably being created…
Comment: MySQL Server Memory Usage
September 1, 2006 By 18 Comments
…tables‘, ’102′ ‘Com_update’, ’15146253′ ‘Com_update_multi’, ’0′ ‘Connections’, ’263413′ ‘Created_tmp_disk_tables‘, ’0′ ‘Created_tmp_files’, ’4001′ ‘Created_tmp_tables…
Comment: Why MySQL could be slow with large tables ?
November 14, 2008 By 139 Comments
… M Handler_read_rnd_next 4,483 M Created_tmp_disk_tables 5,270 Created_tmp_tables 5,274 Created_tmp_files 37 k Key_reads 4,226 Key…] datadir = /var/lib/mysql socket = /var/lib/mysql/mysql.sock user=mysql # Default to using old password format for compatibility with mysql 3.x # clients…
Comment: How much memory can MySQL use in the worst case?
February 19, 2009 By 17 Comments
… for sale and/or rent. We are currently using MySQL and MyISAM tables and we keep running out of memory so the… server runs) Created_tmp_disk_tables 9,208 Select_full_join 1,074(the application is using indexes to join the tables so this puzzles me) Sort_merge_passes 2,602 Opened_tables 1,500 Table_locks_waited 74 hope this is enough information to…
