…=1 –max-time=7200 –max-requests=0 –percentile=95 \ –mysql-user=root –mysql-socket=/tmp/mysql.sock –mysql-table-engine=…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…
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
…size = 8M myisam_max_sort_file_size = 10G #myisam_max_extra_sort_file_size = 10G myisam_repair_threads = 1 myisam_recover socket=/var/lib/mysql/mysql…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
… amazing MySQL manual, especially the option and variable…max_connectionsblogpercona.commanual max_delayed_threadsblogpercona.commanual max_error_countblogpercona.commanual max_heap_table_sizeblogpercona.commanual max_insert_delayed_threadsblogpercona.commanual max_join_sizeblogpercona.commanual max…
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
…/dist/mysql-5.5.30-linux2.6-x86_ | /mnt/nfs/dist/mysql-5.6.10-linux-glibc2. | | MAX_ALLOWED_PACKET | 1048576 | 4194304 | | JOIN_BUFFER_SIZE…:autoextend | | INNODB_PURGE_BATCH_SIZE | 20 | 300 | | PERFORMANCE_SCHEMA_MAX_THREAD_INSTANCES | 1000 | 224 | | SOCKET | /tmp/mysql_sandbox5530.sock | /tmp/mysql_sandbox5610.sock | | INNODB… now allowing MySQL to handle larger queries. Makes sense as amount of memory available is much larger these days. join_buffer_size have…
Post: How is join_buffer_size allocated?
July 5, 2010 By 9 Comments
… examining MySQL configuration, we quite often want to know how various buffer sizes are used. This matters because some buffers (sort_buffer_size…=0; /* End sequentel */ 14271 size=max(thd->variables.join_buff_size, cache->length); 14272 if (!(cache->buff=(uchar*) my_malloc(size,MYF(0)))) 14273 DBUG…
Post: Review of MySQL 5.6 Defaults Changes
October 8, 2012 By 10 Comments
…great summary of defaults changes in MySQL 5.6 compared to MySQL 5.5 In general there are…me. Lets go over them: back_log = 50 + ( max_connections / 5 ) capped at 900 – The large …deal with simple and complicated queries efficiently automatically. join_buffer_size = 256k The default is now double of…
Comment: How is join_buffer_size allocated?
September 22, 2010 By 9 Comments
… from each table in a join when the join can’t use an index.” because even if MySQL decides to scan all index… the join buffer. Also, there is another variable that determines the max size of join buffer and that is max_join_size (no. of rows to be joined not the buffer size).
Comment: How to check MySQL Config files
September 20, 2009 By 7 Comments
…57 [Warning] option ‘max_join_size‘: unsigned value 18446744073709551615 adjusted to 4294967295 090922 2:30:57 [Warning] option ‘max_join_size‘: unsigned value 18446744073709551615…and redistribute it under the GPL license Starts the MySQL database server Usage: /usr/libexec/mysqld [OPTIONS] For more…
Post: A case for MariaDB's Hash Joins
May 31, 2012 By Leave a Comment
… pool size of 6G. The benchmarks compare Block Nested Loop (BNL) Join of MySQL 5.5.24, Batched Key Access (BKA) Join of MySQL 5.6.5 and Block Nested Loop Hash (BNLH) Join of… it always uses the max values join algorithm. If join_cache_level=4 it always uses BNLH (hash join), if join_cache_level=8 it…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
…not just for new connections as in MySQL. This is very helpful for measurement…table_sizes: 0 # InnoDB_trx_id: F00 # QC_Hit: No Full_scan: Yes Full_join: …:03:10 # Attribute pct total min max avg 95% stddev median # ============ === ======= ======= ======= ======= ======= ======= ======= # Count 1 312…
