… the InnoDB Buffer Pool Preloading introduced in MySQL 5.6. Starting with MySQL 5.6 buffer pool dumps can be produced and loaded for faster server warmup after the start. This feature is similar to the Dump/Restore of the… failures that are caused by the log records in the transactional log being overwritten before they are copied by the log…
Post: Percona XtraBackup 2.1.0 'release candidate' for MySQL available for download
May 7, 2013 By Leave a Comment
Post: Percona XtraBackup 2.0.7 for MySQL available for download
May 6, 2013 By 1 Comment
… the InnoDB Buffer Pool Preloading introduced in MySQL 5.6. Starting with MySQL 5.6 buffer pool dumps can be produced and loaded for faster server warmup after the start. This feature is similar to the Dump/Restore of the… failures that are caused by the log records in the transactional log being overwritten before they are copied by the log…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
…? After creating a vCache device with the default configuration, I started with a baseline HDD configuration for MySQL (configuration A, listed… graph. We see the exact same pattern when looking at transaction latency; the baseline numbers are roughly identical for all four…
Post: Percona XtraDB Cluster 5.5.30-23.7.4 for MySQL now available
April 17, 2013 By 2 Comments
…. Bug fixed #1130888 (Seppo Jaakola). If MySQL replication threads were started before running wsrep recovery, this would lead to memory corruption… bugfix for bug #59354 triggered a regression that could cause transaction conflicts. Bug fixed #1158221 (Seppo Jaakola). Galera builds would fail…
Post: When does Innodb Start Transaction ?
January 11, 2011 By 9 Comments
… “not started” status in transaction list. It is only when you read (or write) to INNODB table you can see transaction is started: —TRANSACTION F56AED… really need all data be seen at the time of transaction start you can use “START TRANSACTION WITH CONSISTENT SNAPSHOT” command.
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
… | +—————–+ | REPEATABLE-READ | +—————–+ 1 row in set (0.00 sec) session1 > start transaction; Query OK, 0 rows affected (0.00 sec) session1 > select… the transactions that accessed that table are open. Let’s see this in affect via a simple test case: session1 > start transaction; Query…
Post: MVCC: Transaction IDs, Log Sequence numbers and Snapshots
December 19, 2007 By 3 Comments
… and which was started before transaction 100 have committed. In such case transaction 101 should not see changes done by transaction 100 and will… track when given transaction has committed, in the list of transactions which were active at the time current transaction was started. This is needed…
Post: InnoDB's gap locks
March 27, 2012 By 15 Comments
…. For example: transaction1> START TRANSACTION; transaction1> SELECT * FROM t WHERE i > 20 FOR UPDATE; +——+ | i | +——+ | 21 | | 25 | | 30 | +——+ transaction2> START TRANSACTION; transaction2> INSERT INTO… * FROM t; +——+ | age | +——+ | 21 | | 25 | | 30 | +——+ Start a transaction and delete the record 25: transaction1 > START TRANSACTION; transaction1 > DELETE FROM t WHERE age=25…
Post: Can MySQL temporary tables be made safe for statement-based replication?
May 26, 2008 By 8 Comments
… get two transactions here. This shows us something interesting that isn’t considered in the “all inside one transaction” argument: transactions aren’t… InnoDB table: master > delimiter // master > create procedure test_temp() begin -> start transaction; -> create temporary table test.t(a int) engine=innodb; -> insert…
Comment: Can MySQL temporary tables be made safe for statement-based replication?
May 27, 2008 By 8 Comments
… of action to initiate the transaction before creating your temp table. It seems that merely issuing a “START TRANSACTION” is not enough. For…: START TRANSACTION; INSERT INTO `test`.`ints` VALUES (1); CREATE TEMPORARY TABLE… … COMMIT; … then the temporary table will be created inside the transaction. I’ve never looked at the internals, but if you just issue START TRANSACTION; COMMIT; with nothing in…
