…MySQL internals can enlighten me here. – audit_record_objs : List of database objects (tables…MySQL in PCI or SOX compliant environments, to name just two, artificially complicated, as one had to rely on too much…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
… they tend not to think too much about is if moving…MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL replication? It’s actually much…hundred. This really will open a large window …separate tables and there also exists a users_groups table to …
Comment: MySQL Partitioning - can save you or kill you
April 30, 2013 By 45 Comments
… the use case — * The entire table is too big to be cached, but *…, any INSERT/DELETE/etc always opens all partitions, even before thinking …anywhere in any ‘free’ variant of MySQL. PARTITIONs are scanned one at a… Not much difference. Yes, DROPping an ‘old’ partition is very efficient, much more…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 11 Comments
…isn’t really deleted. The MySQL server keeps an open filehandle to the file, and …of connections all trying to open or close tables can indicate LOCK_open contention. Replication is delayed… allocating too much memory. A runaway server process, or poorly optimized queries, can consume too much memory …
Post: Distro Packages, Pre-built Binaries or Compile Your Own MySQL
September 4, 2012 By 7 Comments
…open source world, with the freedom to customize software to fit every organizational needs, compiling custom MySQL…increasing maximum total number of indexes per table from 64, or maybe your engineering …when troubleshooting for problems and not spend too much time on switching, rather focus on the …
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
…200 tables in this system. innodb_stats_on_metadata is disabled by default in MySQL 5.6 Welcome to much …variables values. I do not expect large impact here. table_open_cache is increased from 400 to 2000 by default…be larger by default as value of 1M is too small to be practical if someone tries to …
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
…tables in MySQL 5.1 Disk Space For MyISAM tables hosting providers used to use disk quotas for MyISAM tables….as temporary tables, so by opening large amount of cursors which are handled as in-memory temporary tables you…some global quotas so it can’t consume too much memory and also you can’t get all…
Post: What to tune in MySQL Server after installation
September 29, 2006 By 118 Comments
…_mem_pool_size This one does not really affect performance too much, at least on OS with decent memory allocators. Still you… case MySQL Server crashes. Value 2 only cause data loss with full OS crash. table_cache – Opening tables can be expensive. For example MyISAM tables mark MYI header to mark table as currently in use…
Post: How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
… transaction. If a transaction remains open for a very long time … be fixed. I see this much too often, and have developed a… INFORMATION_SCHEMA tables that make this simple. Just query the tables, and …port} > /root/tcpdumps/`date +%s`-tcpdump & mysql -e ‘show innodb status\Gshow full processlist’ >…
Post: Using VIEW to reduce number of tables used
September 28, 2007 By 12 Comments
…require at least 16K page in Innodb), keeping all tables open in Innodb dictionary and number of other challenges … users per table it is best way to go, however quite typically this is way too much work and … do not pass user_id value to underlying table MySQL tries to set it to default, which does …
