… there a Percona recommendation for finding Hot Spots in a high load application? …the value). If you make the field an ENUM(‘payed’,'shipped’,'canceled’,'archived…you use a 1-byte character set for CHAR). Here CHARs will …these recommendations true of all versions of MySQL? If not which versions? The …
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…could find in SHOW INNODB STATUS, there are however few which were not available before. In … size 320 MySQL thread id 30898, query id 100626 localhost root Updating update iz set pad…in parent table `test/parent`, in index `PRIMARY`, the closest match we can find is record: PHYSICAL RECORD: n_fields…
Post: Timezone and pt-table-checksum
September 25, 2012 By 1 Comment
… some servers that were located in different timezones. Unfortunately, several of the tables had timestamp fields and were set to a default value of CURRENT_TIMESTAMP. From the manual, here is how MySQL handles timezone locality with timestamp fields… the fly to get the actual rows in need of syncing, it will not find those rows even though pt-table-checksum…
Post: Debugging problems with row based replication
May 6, 2010 By 12 Comments
… | count(*) | +———-+ | 65536 | +———-+ 1 row in set (0.02 sec) My test setup includes a MySQL slave. After … error (many fields omitted): SHOW SLAVE STATUS\G Relay_Log_File: mysql_sandbox25162-relay-bin….tell us what row it couldn’t find though. In our simple example, we know …
Post: Why audit logging with triggers in MySQL is bad for replication
September 29, 2008 By 10 Comments
… with investigating slippage between master and slave in a standard replication setup. The client was …:50:05 So, now I needed to find out what was updating the table. Here …set Value=6 Where Field_ID = 3; Transaction 2 starts, updates and commits. Start Transaction; Update Foo set Value=6 Where Field…
Post: PROCEDURE ANALYSE
March 23, 2009 By 9 Comments
…find …in the table but I’ve omitted everything by few rows. mysql> select * from node procedure analyse() \G *************************** 1. row *************************** Field… sticky | int(11) | NO | | 0 | | +———-+——————+——+—–+———+—————-+ 12 rows in set (0….
Post: Bug#12704861
November 20, 2011 By 1 Comment
…in MySQL…in, 12704861. The fix for our bug is in revision id marko.makela@oracle.com-20110829081642-z0w992a0mrc62s6w (so you can find it in…fields_func(): Add the parameter alloc_mtr, which is NULL (old behaviour in inserts) and the same as local_mtr in…
Post: ORDER BY ... LIMIT Performance Optimization
September 1, 2006 By 100 Comments
… to find 10 rows. …in the leading table. If ORDER BY is going by field from the table which is not first in…| +—-+————-+——-+——+—————+——+———+————-+——+———————————+ 2 rows in set (0.00 sec) In this …needed In some cases MySQL …
Comment: Fixing column encoding mess in MySQL
January 27, 2011 By 32 Comments
Well, I took a look in PHP functions, and didn’t find any binary functions that seem likely to help. the have… REPLACE on test data in MySQL: SET field = REPLACE(field, ‘•’, ‘•’); MySQL said it happily replaced the string in lots of fields (and searching that string returns no rows), but when viewing in a…
Post: Using CHAR keys for joins, how much is the overhead ?
June 18, 2007 By 18 Comments
… data to the client Do not try to find any good meaning for query or schema. For … MyISAM table and join query performed on INT fields: CREATE TABLE `intjoin` ( `i` int(10) unsigned NOT NULL,…in set (1.70 sec) Here is explain if someone curious, it did not really change beside key lengths: mysql> …
