…this case if I index the table I get the following record in the slow query log: # Time: 120911 17:… access type to the tables is “const” MySQL does not count it as access to two tables. In … is possible. For example I might have query which uses some index scans 1000 rows and sends 10… I …
Post: Troubleshooting MySQL Upgrade Performance Regressions
February 15, 2012 By Leave a Comment
…use pt-query-digest to compare workloads on servers. Best if you can analyze full query logs but if this is not…not using debug binary or differently optimized binaries. When you’re about to file a bug or report the problem through MySQL…
Post: Is there room for more MySQL IO Optimization?
January 3, 2013 By 11 Comments
… be cached — system files, binary log, FRM files, MySQL MyISAM system tables etc. Starting MySQL 5.5 MySQL uses asynchronous IO which should allow it… data and indexes scan which will be reflective to large full table scan and index scan queries, though this is really not the point…
Post: MySQL Upgrade Webinar Questions Followup
June 28, 2012 By 7 Comments
… you still need to keep into account possible query changes, replication etc. Q: Is it possible …of importance I would recommend using Percona Server with enabled expand_fast_index_creation feature, as I just…MySQL 5.0 in between so it will convert binary log events, as described here yet it does not…
Post: What's required to tune MySQL?
July 27, 2011 By 4 Comments
… should expect to deliver huge wins. If MySQL is actually badly configured, you can hurt …I see are not configuring the InnoDB buffer pool size or log file size, and not using InnoDB. If … configuration The workload The queries The schema design (table design, data types, indexing, etc) The data …
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…pid-file=/var/run/mysqld/mysqld.pid –log-error=/var/log/mysqld.log mysql 3172 3137 78 Nov19 ? 1-…default users in the mysql.* tables, running mk-duplicate-key-checker to find redundant indexes, and so on… shortcut effort if it’s not useful, e.g. skipping analysis for a query the client’s developers …
Post: MySQL Slow query log in the table
May 31, 2007 By 1 Comment
…indexes would be quite handy I also should tell log table implementation in MySQL…log table if it is allowed or if there is a buffer of slow log queries which is used if log…
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
…Query. Each image comes pre-loaded with the data used in the previous Shard-Query…indexes) # du -sh * 203M ibdata1 128M ib_logfile0 128M ib_logfile1 988K mysql…last post. ICE does not have any indexes (not even primary keys). Here…wait-timeout=300 log-error=/var/log/mysqld-innodb.log max-allowed-packet…
Post: ORDER BY ... LIMIT Performance Optimization
September 1, 2006 By 100 Comments
… simply indexes column. Note: In some cases even if it is possible to use index to do ORDER BY with JOIN MySQL still will not be able to use it as Optimizer is not smart enough… and may end up in slow query log as query which does not use indexes, even if it is quite fast: mysql> explain select * from test order…
Post: MySQL Crash Recovery
July 30, 2006 By 30 Comments
… log and binary log are synchronized. In MySQL 5.0 XA is taking care of this synchronization. .frm Corruption – Few people know MySQL is not… by using LOAD INDEX INTO CACHE statement, for other storage engines it can be done by issuing large index scan queries. Full table scan queries…
