… I used before. Sysbench dataset – 16 tables, each 5M rows, uniform distribution. OLTP_…dirty pages, minimize impact of the memory fragmentation is so significant that becomes bottleneck …correlation with decreasing performance in workloads with MySQL. # Test: POINT_SELECT:throughput, QPS # # Set 1 …
Post: MySQL Storage Engines - PBXT
May 14, 2007 By 6 Comments
…, just as with MyISAM, and you might need to repair tables. This is of course something which is scheduled to be… which are never fragmented and handled efficiently. PBXT team even leads the project to add scalable blob streaming to MySQL which would… for many applications if implemented well. It is too bad MySQL Users Conference only allowed 45 minutes for Storage Engine presentations…
Post: How network can impact MySQL Operations ?
September 1, 2008 By 5 Comments
… window which involved a lot of data copying around between MySQL boxes. We had prepared well and had measured how fast… RAID is powerful enough. This applies to large Innodb tables with not overly fragmented tablespace, or it is easy to become IO…
Post: Improved InnoDB fast index creation
November 6, 2011 By 4 Comments
… table rebuilds without affecting the table size. mysql> SET expand_fast_index_creation=ON; Query OK, 0 rows affected (0.00 sec) mysql> ALTER TABLE… important thing that is worth mentioning is fragmentation. Fast index creation results in much less fragmented indexes because records are inserted in…
Post: Using MyISAM in production
June 17, 2006 By 36 Comments
… many tables which are being repaired, each may allocate myisam_sort_buffer_size and MySQL could crash or go swapping. Second – table will… then rename them back to MySQL database directory. This way accesses to non-checked tables fail with table does not exist error rather… may cause total block if there are long selects running. Fragmentation. This is common problem for pretty much all storage engines…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
… hi amount of concurrent writes to about 6 tables, what version of Innodb/MySQL would you recommend? I’ve been staying at… run to show any table / index fragmentation, without having to run the OPTIMIZE? HT: Since OPTIMIZE rebuilds the whole table, it may last… pages == 1 MB. Then a full table scan would be fast. Maybe the table has become fragmented? Or maybe you have not inserted…
Comment: Working with many files and file system fragmentation
March 18, 2008 By 11 Comments
… tables are optimized periodically b.big tables that are affected by fragmentation can be arranged as 1 file per filesystem c. recently Mysql 5.1 table partitioning allowed… filesystem is immune to fragmentation unfortunately, the only way to reduce it is to have some table options that will pre-allocate…
Comment: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 13 Comments
… same table. I saw this on the mysql web site. But when I moved this column to different table. Even then the fragmentation is not getting reduced. Optimize table reduces the fragmentation…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
… 32 pages of a segment are allocated from ‘fragment extents’ where any individual page can be allocated… HT: ha_innodb.cc in 5.1: static MYSQL_SYSVAR_ULONG(thread_concurrency, srv_thread_concurrency, … example, if ORDER and ORDERLINE tables are joined to form a single table), it might make sense …
Page: Tools
May 30, 2008 By 31 Comments
… Toolkit Percona Toolkit is a great set of tools for MySQL Performance Analyses and maintainence. Must know and have for any… Innodb tables. Very nice to watch what happens to server in the real time. filefrag filefrag is the fool to check fragmentation of the file. Ever wondered how fragmented your tablespace or table on the file level ? iostat…
