…takes too long. In that case often the alternative is to take…mysql_upgrade it tries to check and upgrade all tables which need to be changed but fails miserably with Innodb tables. Recommendation by the mysql…
Post: MySQL optimizer: ANALYZE TABLE and Waiting for table flush
February 27, 2013 By 3 Comments
…check the following blog post for more information: http://www.mysqlperformanceblog.com/2011/10/06/when-does-innodb-update-table…TABLE: mysql> analyze table t; +——–+———+———-+———-+ | Table…long query finishes or kill the query. Also, we have to take…
Post: Working with large data sets in MySQL
July 5, 2007 By 12 Comments
…mySQL teach you ? Of course you have to learn a lot about query optimization, art of building summary tables…after power failure as check and repair may take long hours (this …how you’re going to alter your database because it takes… using keycache) If it does not performance may drop performance…
Post: The tool I've been waiting for years
March 18, 2008 By 10 Comments
…check how pages are cached. For example every second page cached may be helpful for point queries but does…table is cached would allow optimizer to take much smarter decisions in many cases. Lets now see some examples: [root@DB01 mysql…
Post: Innodb undo segment size and transaction isolation
January 12, 2011 By 3 Comments
…Long transactions can also be bad for other reasons such as taking…how long transaction looks: —TRANSACTION 17402D749, ACTIVE 15867 sec, process no 19349, OS thread id 1630148928 MySQL…to check: mysql> select * from information_…table at that point in time. If you use READ-COMMITTED mode Innodb does…
Post: Percona XtraDB Cluster - installation and setup webinar follow up Q&A
October 28, 2012 By 4 Comments
…built-in mysql replication are…Binaries ? A: Check out Jay…long as there are at least 3 datacenters, and the total number of the datacenters is odd. Q: How is configuration for the arbitrator? A: You should use the garbd binary for that, is takes… FLUSH TABLES WITH READ…MyISAM. Q: How does write …
Post: How number of columns affects performance ?
September 28, 2009 By 12 Comments
…tables which have long rows tend to be slower than tables with short rows. I was interested to check…tables is to use covering indexes. I added one to t99v1 table and repeated the query: mysql…
Post: The new cool MySQL patch has landed! Check your queries performance!
October 31, 2007 By 16 Comments
…see those which take less than 1s. Now long_query_time …table is required for query execution Tmp_table will be set. Sometimes that table…MySQL currently allows you to see many per-session statistics for operations with SHOW SESSION STATUS, but that does…_r_wait you can see how much time (in seconds) …
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
…writing Flexviews, I learned how to distribute the …on sets Shard-Query takes relational algebra to its…means that Shard-Query does not have to… database administrator. As long as all of …but right now only MySQL storage nodes are supported… for a UNIQUE CHECK * on the base table: `origin_airport_id…
Post: MySQL Blob Compression performance benefits
January 11, 2008 By 17 Comments
… the table it often makes sense to keep it compressed. Unfortunately MySQL does…MySQL tools. Some people get best of both worlds by taking COMPRESS/UNCOMPRESS functions from the MySQL… I usually run some checks to see how much compression will benefit …forum posts (if they are generally long enough) …
