…. A star schema presents some unique challenge to the database optimizer. The SSB benchmark consists of four sets of queries. Each… table_open_cache_instances=8 sort_buffer_size=128k read_rnd_buffer_size=8M join_buffer_size=8M default_tmp_storage_engine=myisam tmpdir=/dev/shm innodb_undo…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
…that configuration C appeared to produce the most optimal results, I moved on to reviewing FlashCache …101 key_buffer_size = 8M read_buffer_size = 1M read_rnd_buffer_size = 4M bulk_insert_buffer_size = 8M myisam_sort_buffer_size = 8M myisam_max_sort_file_size = 10G myisam_repair_threads = 1 myisam…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…myisam_max_sort_file_sizeblogpercona.commanual myisam_mmap_sizeblogpercona.commanual myisam_recoverblogpercona.commanual myisam_recover_optionsblogpercona.commanual myisam_recover_optionsblogpercona.commanual myisam_repair_threadsblogpercona.commanual myisam_sort_buffer…
Post: What exactly is read_rnd_buffer_size
July 24, 2007 By 4 Comments
… very similar to read_buffer_size which is currently only used by MyISAM tables I thought read_rnd_buffer_size is also MyISAM only. But talking… lucky. The read_rnd_buffer_size is important (optimization works in following conditions): Row pointers are stored in the sort_buffer, not the whole data…
Post: MySQL Server Memory Usage
May 17, 2006 By 21 Comments
… as full table scans, sorts, or need temporary tables as much as read_buffer_size, sort_buffer_size, read_rnd_buffer_size, tmp_table_size of memory might be… inserts may allocate bulk_insert_buffer_size bytes of memory if done to MyISAM tables. myisam_sort_buffer_size used for ALTER TABLE, OPTIMIZE TABLE, REPAIR TABLE commands…
Post: Predicting how long data load would take
May 24, 2007 By 14 Comments
… be set for optimal load speed. Depending on load type MyISAM may benefit from bulk_insert_tree_size increase myisam_sort_buffer_size or key_buffer_size increase. Innodb typically needs large innodb_buffer_pool_size and large…
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 13 Comments
…Optimal WT, RA PhysiclDev Type State Errors Vendor Model Size ========== ==== ======= ====== ======= …size = 32 query_cache_size = 0 tmp_table_size = 64M key_buffer_size = 8M bulk_insert_buffer_size = 8M myisam_sort_buffer_size = 8M myisam_max_sort_file_size = 10G myisam_repair_threads = 1 myisam…
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
… ALTER 100 different tables ? This can be offset by keeping myisam_sort_buffer_size low, but then performance would suffer. Prepared Statements Number – Happily… of course depends on query size which is controlled by max_allowed_packet. However some MySQL optimizations such as equity propagation and…
Post: Percona Server 5.1.60-13.1
December 16, 2011 By Leave a Comment
…sort buffer cannot be more than 4GB even on 64bit architectures. With this bug fix, both the server option –myisam-sort-buffer-size and the |myisamchk| –sort-buffer-size… correct compiled code even if future compilers implement new optimizations. Bug Fixed:#878022 (Laurynas Biveinis) GCC 4.6 has …
Post: MySQL: what read_buffer_size value is optimal ?
September 17, 2007 By 25 Comments
…with MySQL Performance Optimization and Optimization for other applications the better I understand… results with sort performance and today I’ve discovered even read_buffer_size selection may …MyISAM DEFAULT CHARSET=latin1 1 row in set (0.00 sec) Populated it with 75M of rows to reach 4G in size…
