… called general log activated with –log (or –general-log in MySQL 5.1+) start-up parameter. The log writes any query being executed by MySQL to… is slow log enabled by –log-slow-queries parameter (MySQL 5.1 requires also –slow-query-log), which was designed to store poorly performing queries that…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
…Metadata Locking related changes that were introduced in MySQL 5.5.3. It appears that …also means that queries could be written in different order to the binary log breaking locking …Query Cache How does metadata locking behave with query_cache? That is an important question. If Query Cache is enabled…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…MySQL…enable_lockingblogpercona.commanual enable_named_pipeblogpercona.commanual enable…query_logblogpercona.commanual slow_query_log…
Post: Enabling/Disabling query log without server restart in MySQL 5.0
September 13, 2007 By 13 Comments
… you do in MySQL 5.0 and below ? Use Our Patch – With this patch you can get all queries logged as slow queries (with times… general query log – for example connects or queries with syntax errors will not be logged. Enable logging to /dev/null You can enable queries to say “all_queries” log and…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
…MySQL server, you would see an entry like this in the slow query log: # Time: 111229 3:02:26 # User@Host: msandbox[msandbox] @ localhost [] # Query… Note that logging all queries in this fashion as opposed to the general query log, enables us to have the statistics available after the query is …
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
… tables in this system. innodb_stats_on_metadata is disabled by default in MySQL 5.6 Welcome to much faster information_schema queries! innodb_log… in MySQL 5.5 and before it was “ON” by default with query cache size of 0 which makes it disabled. I wish query… change ! thread_cache_size is enabled by default, though I wonder why default value is 9. In any case very welcome change…
Post: Slow Query Log analyzes tools
September 6, 2006 By 84 Comments
…enable logging queries which do not use indexes even if they take less time (–log-queries-not-using-indexes) Slow query log…log all queries slow query log may be growing too rapidly to follow, so we implemented slow query log filter (based on parse_mysql_slow_log…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… query log, is one of the more fruitful ways to analyze the system. What I usually do is ask the client to enable…/slow.log By default, this outputs the top 10 most expensive queries, in total execution time. By the way, the slow query logs in the stock MySQL… microsecond logging and additional information in the slow query log output. The stock MySQL server’s limitation of one-second granularity makes it hide problem queries…
Post: Replication checksums in MySQL 5.6
February 15, 2013 By 3 Comments
…enable them with the following command (they’re disabled by default): master [localhost] {msandbox} ((none)) > set global master_verify_checksum=ON; Query…mysql-bin.000001′ at 2896.’ Conclusion You should not assume that replication checksums in MySQL 5.6 will ensure data integrity in…
Post: A (prototype) lower impact slow query log
September 20, 2012 By 12 Comments
… had to extend the MySQL plugin API to be able to reproduce all the information in the slow query log. The code for my…: straight MySQL (no slow query log): 13 seconds MySQL with slow query log enabled: 18 seconds My audit plugin slow query log: 15 seconds straight Drizzle (no slow query log): 8…
