… to create a more complicated test which runs this query concurrently many times or even workload consisting of several query types. Though it is… the query which performs differently between MySQL Server versions you should: Check Query Plan Run EXPLAIN to see if plans for the query are…
Post: Percona Testing: Innodb crash / recovery tests available
December 21, 2011 By Leave a Comment
…and restarted: $ ./kewpie.py –suite=innodbCrash –basedir=mysql-5.5 –test-debug crashCommitAfter_test 20111221-142500 INFO MASTER_PORT: 9307 …queries for all tests: ./kewpie.py –suite=innodbCrash –basedir=/path/to/basedir –force –randgen-seed=time –repeat=3 gets us: 20111221-142820 TEST…
Post: Upgrading MySQL
January 5, 2010 By 24 Comments
… different MySQL version is taking a lot of time you may wish to create second QA/dev environment just for this project. Query… will run SELECT queries on both new and old MySQL installations and check result set, explain plan and execution time, reporting you on… Testing Running single stream of queries with good speed is not enough. You also need to perform stress testing to ensure both MySQL does…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
… Server you can do better as you can query temporary tables too: mysql> select sum(data_length+index_length) from …16384 INDEX_LENGTH: 0 CREATE_TIME: NULL UPDATE_TIME: NULL *************************** 2. row *************************** SESSION_ID: 7234 TABLE_SCHEMA: test TABLE_NAME: tmp ENGINE: …
Post: MySQL performance: Impact of memory allocators (Part 2)
March 8, 2013 By 12 Comments
…time I wrote about memory allocators and how they can affect MySQL performance in general. This time… – very simple query – SELECT c FROM sbtest WHERE id=N. Test workload with this query allows … with decreasing performance in workloads with MySQL. # Test: POINT_SELECT:throughput, QPS # # Set 1 – …
Post: Percona XtraDB Cluster reference architecture with HaProxy
June 20, 2012 By 63 Comments
… can be done, but because of optimistic locking at commit time, rollbacks can happen if we have conflicting writes. In the… sec) mysql> flush privileges; Query OK, 0 rows affected (0.00 sec) Populate the table with data for the benchmark. # sysbench –test=oltp –db-driver=mysql –mysql-engine…
Post: Impact of the sort buffer size in MySQL
October 25, 2010 By 8 Comments
…=100000 COUNT=0 while [ "$NUMROW" -gt "$COUNT" ] do UUID=`uuidgen` mysql test -e “insert into sorttest value (‘$UUID’);” let “COUNT=COUNT+1… the time required to perform 12 queries like ‘select * from sorttest order by data limit 78000,1′ with, of course, the query cache… the graph is that the expected correspondence between the time for the queries and the number of sort merge passes. For the…
Post: Testing MySQL column stores
August 16, 2010 By 15 Comments
… of my analysis focused on testing specific MySQL functionally with Infobright’s storage engine. A lot of my tests involved corner or edge… it could not run some of the queries. ICE supports almost all of the MySQL aggregation functions. Notably, GROUP_CONCAT is not… time” than InfiniDB given the inconsistencies that I encountered. I will try to reproduce the problems on InfiniDB into easily reproducible test…
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
… values from MySQL 5.5.30 and MySQL 5.6.10 to the different tables and ran the query: mysql [localhost] {msandbox} (test) > select var55… | 10000 | 1556 | | SQL_MODE | | NO_ENGINE_SUBSTITUTION | | INNODB_OLD_BLOCKS_TIME | 0 | 1000 | | LOG_ERROR | /mnt/data/sandboxes/msb_5_5… MySQL 5.5 and before it was “ON” by default with query cache size of 0 which makes it disabled. I wish query…
Post: mk-query-digest, query comments and the query cache
…time, cpu time, mysql query times, etc, and automatically places this information into the Apache environment. It also includes support for “augmenting” SQL queries… test. You can enable query cache stripping in Percona Server at runtime: mysql> set global query_cache_strip_comments=’ON’; Query OK…