… rows we have mysql> set max_heap_table_size=1000000000; Query OK, 0 rows affected (0.00 sec) mysql> set tmp_table_size=1000000000; Query OK… on Linux Performance of Disk MyISAM tables may not scale proportionally with table size, even when all data fits in memory MEMORY temporary tables can…
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 13 Comments
…goal was to compare performance with different IO alignment, not different MySQL configurations, I didn’t try out different MySQL versions or …cache_size = 16M max_heap_table_size = 64M thread_cache_size = 32 query_cache_size = 0 tmp_table_size = 64M key_buffer_size = 8M bulk_insert_buffer_size = 8M…
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
… Shard-Query will perform on each database. To do the size comparison, I used the du utility: InnoDB file size on disk: 42GB…-links table-definition-cache=16384 table-open-cache=128 thread-cache-size=32 thread-stack=256K tmp-table-size=64M transaction-isolation=READ-COMMITTED user=mysql…
Post: Side load may massively impact your MySQL Performance
November 13, 2011 By 7 Comments
… typical to hear complains about MySQL interactive performance – serving simple standard …mysql –mysql-host=localhost –mysql-table-engine=innodb –mysql-db=test –oltp-table-name=md_cache_test_small –oltp-table-size=1100000 –mysql-user=msandbox –mysql-password=msandbox –mysql-socket=/tmp/mysql…
Post: DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
… rows table: sysbench –test=oltp –oltp-table-size=20000000 –mysql-table-engine=innodb –mysql-socket=/tmp/mysql_sandbox5524.sock –mysql-db=test –oltp-table-name=…MySQL. Conclusion The new DROP TABLE related fixes in MySQL >= 5.5.23 have certainly reduced the performance hit, and the performance…
Post: New SpecJAppServer results at MySQL and Sun.
November 12, 2008 By Leave a Comment
…_size = 32k thread_cache = 16 query_cache_size = 0M thread_concurrency = 8 max_heap_table_size=200M log-output = FILE log-slow-queries=/tmp/mysql… log for a little bit lless of performance. innodb_thread_concurrency = 0 Good! So Innodb performed best in this workload without restricting…
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
… to ALTER 100 different tables ? This can be offset by keeping myisam_sort_buffer_size low, but then performance would suffer. Prepared Statements…_table_size or max_prepared_stmt_count are designed to protect from typical application mistakes not from someone intentionally trying to bring MySQL…
Post: MySQL File System Fragmentation Benchmarks
March 21, 2008 By 28 Comments
… inserts going to random tables. I used default MySQL settings for MyISAM (table_cache=64) and set innodb_buffer_pool_size=8G innodb_flush… than 100 tables. Read performance starts close but degrades less for 10 and 100 tables and when better again for 10000 tables. I can… from these results – Concurrent growth of many tables causes data fragmentation and affects table scan performance nadly – MyISAM suffers worse than Innodb – Innodb…
Post: How fast can you sort data with MySQL ?
August 18, 2007 By 26 Comments
… system. Lets now increase sort_buffer_size and see how performance is affected: set sort_buffer_size=100000; mysql> select * from gt order by…_size to 100K gives quite expected performance benefit, now we’re just 2 times slower than table scan of the query and considering table size…
Post: MySQL 5.6.7-RC in tpcc-mysql benchmark
October 8, 2012 By 22 Comments
MySQL 5.6.7 RC is there, so I decided to test how it performs in tpcc-mysql workload from both performance and stability… = 10 table_open_cache = 2048 max_allowed_packet = 16M binlog_cache_size = 16M max_heap_table_size = 64M sort_buffer_size = 4M join_buffer_size = 4M thread_cache_size = 1000 query_cache_size = 0 query…
