… compromise, either of performance, or of accuracy of randomness. The ORDER BY RAND() solution is known to have poor performance, but it… in this case to force MySQL to scan the `title` table first, grouping by kind_id in index order. This made the first table in the EXPLAIN seem like it was scanning more rows. But by…
Post: The small improvements of MySQL 5.6: Duplicate Index Detection
May 31, 2013 By Leave a Comment
…) In previous versions of MySQL, you can create two indexes with the same columns (in the same order) and the server will not complain. If we execute the same sentences in MySQL 5.6, the… that could potentially impact our performance, and should be avoided. By the way, a good practice to avoid this is always…
Post: How to fix your PRM cluster when upgrading to RHEL/CentOS 6.4
May 29, 2013 By 2 Comments
…(always considered as Technology Preview by RedHat) provided with 6… active cluster nodes in order to deliver membership and …MySQL [p_mysql] (unmanaged) p_mysql:0 (ocf::percona:mysql): Master percona1 (unmanaged) p_mysql:1 (ocf::percona:mysql): Slave percona2 (unmanaged) p_mysql:2 (ocf::percona:mysql…
Comment: Open Source, the MySQL market (and TokuDB in particular)
May 20, 2013 By 13 Comments
…a migration was virtually a rewrite. (Today moving from MySQL to/from Oracle/MSSql/etc is even more painful… yet a different way. “History — know the past, in order to extrapolate to the future.” It will be … (in the US), there were 100 auto manufacturers. By the 1970s there were only the “Big 4″; …
Post: Is your MySQL buffer pool warm? Make it sweat!
April 16, 2013 By 6 Comments
… order to log every query. (See part two for handling massive slow log volume.) The slow logs are served, via HTTP, by mysql… Playback by streaming the slow log from the active server. wget -q -O – http://master_server:3307/slow | percona-playback –mysql-host 127.0.0.1 –mysql-username playback –mysql-password PaSSwOrd –mysql-schema schema_name –query-log-stdin…
Post: Percona Server for MySQL 5.5.30-30.2 now available
April 10, 2013 By 10 Comments
… Server for MySQL was built with YaSSL which could cause some of the programs that use it to crash. Fixed by building…). Reduced the overhead from innodb_pass_corrupt_table value checks by optimizing them for better CPU branch prediction. Bug fixed #1125248… Kopytov). Ported back from the upstream MySQL 5.6 the fix for unnecessary log_flush_order_mutex acquisition. Bug fixed #1163262 (Alexey…
Post: Keynotes, BOFs, and the Community Networking Reception at Percona Live MySQL Conference and Expo
April 15, 2013 By 1 Comment
… the “Impact of MySQL 5.6 and its Future in the Cloud”. Moderated by me, the panel will include MySQL industry leaders Simone… focus on MySQL 5.6 and how MySQL must evolve if it is to remain competitive in the new world order of the cloud and big data. If you can join us in Santa Clara for the Percona Live MySQL Conference…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…effect on standard MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL replication? It’…ordering really, really matters (really!). By enforcing replication to all nodes, we can (simultaneously) establish global ordering for the transaction, so by…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
…-only transactions, start suffering from the trx_list overhead created by concurrent updates. Once we step away from this spherical read… –mysql-table-engine=INNODB –mysql-socket=/tmp/mysql.sock –oltp-point-selects=1 –oltp-simple-ranges=0 –oltp-sum-ranges=0 –oltp-order-ranges… –mysql-table-engine=INNODB –mysql-socket=/tmp/mysql.sock –oltp-point-selects=9 –oltp-simple-ranges=0 –oltp-sum-ranges=0 –oltp-order-ranges…
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
… about Percona XtraDB Cluster (PXC) for MySQL. I actually had more material than I covered (by design), but one thing I regret… replication feedback mechanism, unlike anything you find in standard async MySQL replication. It is my belief that the lack of understanding… of ensuring transactions are copied to all nodes and global ordering is established, but apply and commit is asynchronous on all…
