…Performance_schema_rwlock_classes_lostblogpercona.commanual Performance_schema_rwlock_instances_lostblogpercona.commanual Performance_schema_table_handles_lostblogpercona.commanual Performance_schema_table_instances_lostblogpercona.commanual Performance…
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
…_WAITS_HISTORY_SIZE | 10 | 5 | | PERFORMANCE_SCHEMA_EVENTS_WAITS_HISTORY_LONG_SIZE | 10000 | 100 | | PERFORMANCE_SCHEMA_MAX_RWLOCK_INSTANCES | 1000000 | 1724 | | PERFORMANCE_SCHEMA_MAX_TABLE_HANDLES…_BATCH_SIZE | 20 | 300 | | PERFORMANCE_SCHEMA_MAX_THREAD_INSTANCES | 1000 | 224 | | SOCKET | /tmp/mysql_sandbox5530.sock | /tmp/mysql_sandbox5610.sock | | INNODB_FILE_PER_TABLE | OFF…
Post: MySQL Blob Compression performance benefits
January 11, 2008 By 17 Comments
…’re storing text of significant size in the table it often makes sense to keep it compressed. Unfortunately MySQL does not provide compressed… row sizes will reduce about 3 times after compression (some XML data) while in practice table size reduced over 5 times and performance gains…
Post: Researching your MySQL table sizes
March 17, 2008 By 28 Comments
…size, round(sum(index_length)/sum(data_length),2) idxfrac FROM information_schema.TABLES WHERE table_name like “%performance_log%”; +——–+———+———+——-+————+———+ | tables | rows | data | idx | total_size…
Post: How to find MySQL queries worth optimizing ?
September 11, 2012 By 6 Comments
… Rows_read: 0 # Bytes_sent: 213 Tmp_tables: 0 Tmp_disk_tables: 0 Tmp_table_sizes: 0 # InnoDB_trx_id: 12F14 SET timestamp=1347398285… lookup is being perform but as only actual rows which are found and returned up to the top level MySQL part for… Rows_read: 1 # Bytes_sent: 719 Tmp_tables: 0 Tmp_disk_tables: 0 Tmp_table_sizes: 0 # InnoDB_trx_id: 12F1D SET timestamp=1347398722…
Post: Innodb Table Locks
July 31, 2012 By 4 Comments
… IN SHARE MODE so it performs locking reads to validate our theory: —TRANSACTION 12305, ACTIVE 9 sec mysql tables in use 2, locked 2 8316 lock struct(s), heap size 1948088, 10008317 row lock(s) MySQL thread id 53173… sec fetching rows mysql tables in use 1, locked 1 9417 lock struct(s), heap size 915896, 696679 row lock(s) MySQL thread id…
Post: When Does InnoDB Update Table Statistics? (And When It Can Bite)
October 6, 2011 By 7 Comments
…perform the updates aside from the first opening of the table or manually running ANALYZE TABLE on it? The 2 instances below are documented from the MySQL…: 34187 Tmp_tables: 1 Tmp_disk_tables: 0 Tmp_table_sizes: 0 SET timestamp=1316767697; show table status …
Post: Is MySQL 5.6 slower than MySQL 5.5?
February 18, 2013 By 23 Comments
…_6_10# sysbench –test=oltp –mysql-socket=/tmp/mysql_sandbox5610.sock –mysql-user=msandbox_rw –mysql-password=msandbox –oltp-table-size=1000000 –num-threads=1 –oltp… run For single thread MySQL 5.5 is 11% faster than MySQL 5.6. If you disable Performance Schema in MySQL 5.6 comes…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
… tuning was done. The goal was to see how MySQL 5.6 performs out-of-the-box as compared to 5.5… pool in pages afterwards: mysql> select sq.*, pages / (@@innodb_buffer_pool_size / 16384) * 100 pct_buffer_pool from ( select table_name, index_name… (0.00 sec) mysql> select sq.*, pages / ((@@innodb_buffer_pool_size / 16384)) * 100 pct_buffer_pool from ( select table_name, index_name, count…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… our book, High Performance MySQL 2nd Edition (it’…tables and Created_disk_tmp_tables, I’ll paste in mysql> show global variables like ‘%table_size%’; +———————+———–+ | Variable_name | Value | +———————+———–+ | max_heap_table_size | 268435456 | | tmp_table_size…
