…Handler_read_key 508833 623738 622184 508913 507516 Handler_read_next 574320 574320 572889 574320 572889 Handler_read_rnd…read, which is completely in line with how the counters behave with MRR, but the value for counter Handler_read…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
…-memory workload Now let’s see how effective are the join optimizations …to MySQL 5.5 While with join_buffer_size set to 6M and read_rnd_buffer_size set to…Handler_read_key’, ‘Handler_read_next’ and ‘Handler_read_rnd_next’. MariaDB 5.5 with Hash Joins enabled is doing less Handler reads as compared to…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
I have been working with Peter in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking optimizer enhancements one by one. So in the same way this blog post is aimed at a new optimizer enhancement Index Condition …
Post: Joining on range? Wrong!
May 17, 2010 By 10 Comments
…how the query performed in greater detail: SHOW STATUS LIKE ‘Handler_read%’; +———————–+——–+ | Variable_name | Value | +———————–+——–+ | Handler_read_first | 0 | | Handler_read_key | 3 | | Handler_read_next | 118181 | | Handler_read_prev | 0 | | Handler_read_rnd…
Post: MySQL: Followup on UNION for query optimization, Query profiling
August 14, 2006 By 12 Comments
…Handler_read_prev | 0 | | Handler_read_rnd | 0 | | Handler_read_rnd_next | 0 | | Handler_rollback | 0 | | Handler_savepoint | 0 | | Handler_savepoint_rollback | 0 | | Handler_update | 0 | | Handler_write | 14 | +—————————-+——-+ 15 rows in set…run SHOW STATUS to see how counters …
Comment: MySQL Server Memory Usage
September 1, 2006 By 18 Comments
…Handler_commit’, ’19092941′ ‘Handler_delete’, ’0′ ‘Handler_discover’, ’0′ ‘Handler_read_first’, ’1100773′ ‘Handler_read_key’, ’2491307870′ ‘Handler_read_next’, ’1266206297′ ‘Handler_read_prev’, ’0′ ‘Handler_read_rnd‘, ’234159075′ ‘Handler_read_rnd_next’, ’2358572961′ ‘Handler…
Comment: Why MySQL could be slow with large tables ?
November 14, 2008 By 139 Comments
… 10,43% update 30k 47,19 0,89% set option 1,189 1,84 0,03% I …query with ORDER BY, LIMIT and with paging — Handler_read_rnd 12 M Handler_read_rnd_next 4,483 M Created_tmp_disk_… from MyISAM to InnoDB (if yes, how to configure InnoDB for best performance?) – what parameters i need to insert manually …
