… some interesting information about how Shard-Query will perform on each database. To do…20 > shards.ini Running the test For best performance, you should run the …cache=16384 table-open-cache=128 thread-cache-size=32 thread-stack=256K tmp-table-size=64M transaction-isolation=READ-COMMITTED user=mysql…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 4 Comments
…cache_incremental=on’ optimizer_switch=’join_cache_hashed=on’ optimizer_switch=’join_cache_bka=on’ join_cache…to provide the best possible query performance. As I mentioned at the…counters. Counter Name MySQL 5.5 MySQL 5.6 MySQL 5.6 w/ join… to run tests to see what specific types of queries would …
Post: Getting real life query speeds with MySQL
January 10, 2007 By 10 Comments
To check for query performance improvements followed indexing/query changes or MySQL configuration changes our customers often decide to run the query and see if…is often using SELECT SQL_NO_CACHE or disabling QueryCache for the test. This works by blocking query cache but still repeated runs execute…
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 13 Comments
…caches were clean. OLTP benchmark As the goal was to compare performance with different IO alignment, not different MySQL…cache = 2048 max_allowed_packet = 16M binlog_cache_size = 16M max_heap_table_size = 64M thread_cache_size = 32 query_cache…
Post: JOIN Performance & Charsets
October 21, 2008 By 2 Comments
… a significant impact on the performance of your queries. Take the following example, using…cache count(`test`.`t1`.`char_id`) AS `COUNT(t1.char_id)` from `test`.`t1` join `test`.`t2` where (`test`.`t1`.`char_id` = convert(`test…33 to 3.12 seconds. This test was performed with MySQL 5.0.67, FreeBSD 7,…
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… time required to perform 12 queries like ‘select * from sorttest order by data limit 78000,1′ with, of course, the query cache disabled. I…
Post: Is there room for more MySQL IO Optimization?
January 3, 2013 By 11 Comments
…cached — system files, binary log, FRM files, MySQL MyISAM system tables etc. Starting MySQL 5.5 MySQL… I have an old test server having 4*7200RPM…buffered IO mode the query was taking almost …performance should be better as it has less overhead with double buffering as well as more information MySQL…
Post: MySQL Wish for 2013 - Better Memory Accounting
December 31, 2012 By 6 Comments
…Performance Schema improvements in MySQL 5.6 I think we’re in the good shape with insight on what is causing performance… or Query Cache but amount of memory used for example for Table Cache …MySQL on the memory diet. It would be easy to extend QA suite to check for peak memory usage after each test…
Post: How fast can you sort data with MySQL ?
August 18, 2007 By 26 Comments
… table as I used for MySQL Group by Performance Tests to see how much MySQL can sort 1.000.000 …_buffer_size ? mysql> set sort_buffer_size=100000000; Query OK, 0 rows affected (0.00 sec) mysql> select * from…CPU in question was Pentium 4 having 1024K of cache. A while ago I already wrote what large…
Post: The new cool MySQL patch has landed! Check your queries performance!
October 31, 2007 By 16 Comments
…queries and to catch those which run less than a second as they can also be a performance… Normally MySQL will not write into slow log any queries executed by…passes: 0 QC_Hit tells whether query cache hit occurred or not. If …query SELECT COUNT(1) FROM t2; Important note: Although the patch was tested…
