…a primary key. After running an analyze on a table with…MySQL can avoid temporary table or filesort for group by by this column. This works because by scanning data in index order MySQL gets data in…
Post: How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
…a while, use mk-query-digest to convert this into a query log, and examine the log. In MySQL 5.1 and newer with…with full server logging. There was a transaction that was blocking others and had locks and undo log records…
Post: Faster Point In Time Recovery with LVM2 Snaphots and Binary Logs
February 23, 2012 By 3 Comments
…mysql> alter table employees add column age smallint unsigned not null default 0; Query OK, 300024 rows affected (13.28 sec) Records…
Post: Using Flexviews - part two, change data capture
March 25, 2011 By 26 Comments
…with an error. It will exit with a message “setup completed” otherwise. Verify installation The binary log stores it progress in a metadata table: $ mysql…Query OK, 2 rows affected (0.00 sec) Records: 2 Duplicates: 0 Warnings: 0 And delete data in a second transaction: mysql…
Post: MySQL Slow query log in the table
May 31, 2007 By 1 Comment
…table with a lot of indexes may be significant overhead, so you can instead create analyze_low_log table of similar structure with…records by physical position quickly without need to have indexes would be quite handy I also should tell log table implementation in MySQL…
Post: Read/Write Splitting with PHP Webinar Questions Followup
January 23, 2013 By 4 Comments
…queries your application runs. Q: Hello, was there any good experiences with MySQL Proxy (RW-splitting)? A: Most solutions with MySQL…in his recent webinar, “The Hazards of Multi-writing in a Dual-Master Setup.” I encourage you to watch the recording…
Post: Debugging problems with row based replication
May 6, 2010 By 12 Comments
…get some dummy data: insert into repl.t1 select NULL from t1; Query OK, 1 row affected (0.01 sec) Records… execute Update_rows event on table repl.t1; Can’t find record in ‘t1′, Error_code: 1032;… log file: mysql_sandbox25162-relay-bin.000002 at position: 340718. MySQL 5.1 ships with a new version of…
Post: Using LVM for MySQL Backup and Replication Setup
August 21, 2006 By 53 Comments
…be in trouble as you will not get…MySQL and run FLUSH TABLES WITH READ LOCK Note – this command may take a while to complete if you have long running queries…tables, but before that you should probably record binary log position which is done by running SHOW MASTER STATUS – This is binary log position…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
…a “free space” in Innodb tablespace to grow significantly. Q6: Does Innodb policy replacement algorithm takes into account page position in…get group commit again. HT: I do not think so. Sergei Golubchik serialized the MySQL binlog write and the InnoDB log flush with a…
Post: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
…with something typical but not if you’re doing something unusual, which people do quite frequently with MySQL…table in database A and a while after accessed table in database B, you will see records in…in the same position or in another location ? Does row ever split into multiple parts like with…
