… in MySQL 5.5, you will succeed without errors or warnings: mysql> ALTER TABLE test ADD INDEX (…clustered index, execute: ALTER TABLE `test`.`test` DROP INDEX `redundant`, ADD INDEX `redundant` (`col2`); # ######################################################################## # Summary of indexes …
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
…, I delivered a six-hour tutorial about Percona XtraDB Cluster (PXC) for MySQL. I actually had more material than I covered (by… example configuration tuning flow control in a master/slave cluster might be: mysql> set global wsrep_provider_options=”gcs.fc_limit=500… translates into number of unique key lookups into the certification index, which is a hash table. A small fc_limit does…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…a single row (well, the PRIMARY KEY index entry for that row). This means …standard MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL replication?…cluster-wide is once per RTT. What about WAN clusters? Callaghan’s law applies to WAN clusters as…
Post: Percona Server 5.5.30-30.2 rerelease fixes non-restart issue
April 24, 2013 By Leave a Comment
…dpkg and binary packages remain unchanged. Percona XtraDB Cluster was also affected by this bug and … key constraint which implied an implicit secondary index with the same name. Fixed by detecting … (Alexey Bychko). Percona Server for MySQL was missing help texts in the MySQL client because the help …
Post: How to recover table structure from InnoDB dictionary
April 22, 2013 By 4 Comments
… indexes of the table. mysql> select * from SYS_TABLES WHERE NAME=’sakila/actor’; +————–+—–+——–+——+——–+———+————–+——-+ | NAME | ID | N_COLS | TYPE | MIX_ID | MIX_LEN | CLUSTER_NAME | SPACE | +————–+—–+——–+——+——–+———+————–+——-+ | sakila/actor | 741 | 4 | 1 | 0 | 0 | | 738 | +————–+—–+——–+——+——–+———+————–+——-+ SYS_INDEXES This table lists all indexes the table has…
Comment: State of the art: Galera - synchronous replication for InnoDB
April 23, 2013 By 15 Comments
… seconds to mysql 5.1 and in about 6-9 seconds on mariadb 5.5, while the galera two-node cluster seems…-cols=6 –number-char-cols=6 –auto-generate-sql-secondary-indexes=3 –auto-generate-sql –csv=/tmp/mysqlslap_3index_innodb.csv…=100000 MariaDB-Galera-server-5.5.29-1.x86_64 mysql-5.1.67-1.el6_3.x86_64 MariaDB-server…
Post: Find and remove duplicate indexes
June 20, 2012 By 9 Comments
… a clustered index and that means that the secondary keys contains the primary key column. Let’s see the following example: mysql> show… a prefix of the clustered index [...] # To shorten this duplicate clustered index, execute: ALTER TABLE `test`.`t` DROP INDEX `name`, ADD INDEX `name` (`name`); # Key age…
Post: MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
… you’re looking for a lot. This will cause data clustering done by these columns which can be helpful if you… prepdefined A: MySQL Server will not automatically define any indexes for you. Hopefully your CMS already comes with reasonable set of indexes, if… more details. Q: how mysql use index for group by? A: If you have Index on the column MySQL can avoid temporary table or…
Post: Percona Live MySQL Conference and Expo 2013 – News from the Committee – Tutorial Selection Complete
December 3, 2012 By 1 Comment
… all this material in less time. Cookbook for Creating INDEXes — All about Indexing Now for one of my former colleages: Rick James… MySQL conference. There are several MySQL HA related tutorials: Using Tungsten Replicator to solve replication problems (3 hr) Ramp-up tutorial for MySQL Cluster…
Post: Percona XtraDB Cluster: Failure Scenarios with only 2 nodes
July 25, 2012 By 6 Comments
…index_size | 2 | | wsrep_cluster_conf_id | 18446744073709551615 | | wsrep_cluster_size | 1 | | wsrep_cluster_state_uuid | 8dccca9f-d4b8-11e1-0800-344f6b618448 | | wsrep_cluster…use the mysql server: [root@percona1 ~]# mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL …
