…MySQL could crash or go swapping. Second – table will be locked while repair is going. If this is frequently used table…uses table locks and has concurrent inserts which can go concurrently with selects. This is sometimes presented as great concurrency for inserts…
Post: Fighting MySQL Replication Lag
September 22, 2008 By 7 Comments
…millions of simple updates instead of one large update to help MySQL replication lag it is not … using INSERT … SELECT – which is in similar to what I just described but can be much worse as SELECT…function which will take SELECT query and the table to which store its result set and use in your …
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
… can have a really large log file generated. … 1.00 0.00 INSERT poller_output # MISC 0xMISC …use to gather more data about the underlying tables involved and the query execution plan used by MySQL. The end result…selecting every column from all the tables involved in the query, probably selecting…
Post: MySQL File System Fragmentation Benchmarks
March 21, 2008 By 28 Comments
…tables and does specified number of inserts going to random tables. I used default MySQL settings for MyISAM (table…tables which could be because of extent allocation for rather large tables. For 10000 tables we had just 1000 of 4K rows in the table…
Post: The perils of InnoDB with Debian and startup scripts
January 28, 2009 By 13 Comments
…buffer pool as large as we’d…result | insert … | 6351 | user | | NULL | 6355 | user | | NULL | 6356 | user | statistics | select … | 6357 | user | statistics | select … | 6358 | user | Sending data | select … | 6359 | user | statistics | select… 500 mysql tables in use 7, locked 0 MySQL thread…
Post: Using VIEW to reduce number of tables used
September 28, 2007 By 12 Comments
…used on massive scale (blog hosting, forum hosting etc), resulting of hundreds of thousands if not millions of tables…used to ensure we do not insert data in the view which will be invisible. The VIEW approach works for SELECT…table MySQL…
Post: Side load may massively impact your MySQL Performance
November 13, 2011 By 7 Comments
…mysql-socket=/tmp/mysql_sandbox5516.sock prepare Running Sysbench and MySQLDump. Note we run them in the loop to see how result…mysql [localhost] {msandbox} (information_schema) > select…note MySQL actually uses midpoint insertion for…MySQL has buffer pool which can be easily washed away by large table…
Post: Cache Performance Comparison
August 9, 2006 By 74 Comments
…result from the cache and ship it back, so large…MySQL queries. On Selecting from the table I should note MySQL is rather fast selecting from the table…TABLE `test` ( `k` varchar(60) NOT NULL default ”, `val` varchar(255) default NULL, PRIMARY KEY (`k`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8; INSERT…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
… results…table scan would be fast. Maybe the table has become fragmented? Or maybe you have not inserted…large data manageable. MySQL Master Master Manager can help you to automate it a bit. I also like to keep tables…select * from table where id=5 show innodb status: Hash table size 10624987, used…
Post: Impact of the sort buffer size in MySQL
October 25, 2010 By 8 Comments
…mysql test -e “insert into sorttest value (‘$UUID’);” let “COUNT=COUNT+1″ done I know, I could have used the uuid() function of MySQL…useful to interpret the results. The figure below shows a graphical representation of the results…
