… in listening to the presentation, it’s currently up and available for viewing over at percona…in file: ‘./mysql/servers.frm’ ERROR: 1033 Incorrect information in file: ‘./mysql/servers.frm’ Running mysql_install_db under… –skip-grant-tables and insert a few rows into an InnoDB table, but trying to …
Post: MySQL 5.6.10 Optimizer Limitations: Index Condition Pushdown
March 14, 2013 By 2 Comments
…_INCREMENT=22187769 DEFAULT CHARSET=utf8; The table had 22 million rows, with approximately 8 million of them having role_id = 1… 1 row in set (0.00 sec) I reported this issue to Oracle and they confirmed that this is the intended/current status of the MySQL 5.6.10 optimizer. Other interesting things to…
Post: Can we improve MySQL variable handling ?
February 18, 2012 By 8 Comments
… way to read it: mysql> set global sort_buffer_size=DEFAULT; Query OK, 0 rows affected (0.00 sec) mysql> select @@global.sort_buffer_size; +—————————+ | @@global.sort_buffer_size | +—————————+ | 2097152 | +—————————+ 1 row in set (0… dealing with MySQL variables in automated way a lot more convenient would be extending INFORMATION_SCHEMA.GLOBAL_VARIABLES Currently as of MySQL 5…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
… take a look at procfs for MySQL process: root@ubuntu:/var/log/mysql# cat /proc/19018/stat 19018 …SENT: 336986112 BINLOG_BYTES_WRITTEN: 0 ROWS_FETCHED: 485139 ROWS_UPDATED: 0 TABLE_ROWS_READ: 610954 SELECT_COMMANDS: … which you can use to guess whenever current IO subsystem can handle it or whenever …
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
… to see how much memory is being used by current MEMORY tables: mysql> select sum(data_length+index_length) from information_schema… tables (both in memory and not): mysql> select * from information_schema.global_temporary_tables \G *************************** 1. row *************************** SESSION_ID: 7234 TABLE_SCHEMA…_NAME: tmp ENGINE: MEMORY NAME: #sql516_1c42_1 TABLE_ROWS: 2 AVG_ROW_LENGTH: 257 DATA_LENGTH: 126984 INDEX_LENGTH: 0 CREATE…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But …_row_lock_current_waitsblogpercona.commanual Innodb_row_lock_timeblogpercona.commanual Innodb_row_lock_time_avgblogpercona.commanual Innodb_row_lock_time_maxblogpercona.commanual Innodb_row_…
Post: The new cool MySQL patch has landed! Check your queries performance!
October 31, 2007 By 16 Comments
….503016 Lock_time: 0.000048 Rows_sent: 56 Rows_examined: 1113 LOGGING OF THE REPLICATED STATEMENTS Normally MySQL will not write into slow…. INNODB USAGE The final part are the InnoDB usage statistics. MySQL currently allows you to see many per-session statistics for operations…: 4 # Query_time: 0.503016 Lock_time: 0.000048 Rows_sent: 56 Rows_examined: 1113 # QC_Hit: No Full_scan: No Full…
Post: Percona Server 5.5.10 (Release Candidate)
April 4, 2011 By 4 Comments
… Biveinis) Variable Changes Old status variable innodb_row_lock_numbers was renamed to innodb_current_row_locks. (Yasufumi Kinoshita) Old system variable innodb_enable_unsafe_group_commit was deleted. The existing MySQL variable innodb…
Post: Percona Server on the Raspberry Pi: Your own MySQL Database Server for Under $80
February 25, 2013 By 10 Comments
…caption] A small disclaimer first: Arch Linux is not currently on our list of supported OS’es (i.e….row-level locking, and foreign keys | YES | YES | YES | [...] mysql> SELECT “Hello World!” AS “Success!” \G *************************** 1. row *************************** Success!: Hello World! 1 row…
Post: What MySQL buffer cache hit rate should you target
June 29, 2006 By 5 Comments
… – something you would not see otherwise. The bad luck is – MySQL currently does not provide this information (it exists in plans). The… Key_writes for MyISAM tables (note this does not include row data access, so you’re a bit in trouble) or… file writes” from SHOW INNODB STATUS for Innodb tables. In MySQL 5.0+ you can also use Innodb_data_reads, and…
