…-Tree index lookups have some limitations in cases such as range scans, where index parts after the part on which range condition is…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…then for each value of ‘pk_column’ which is a part of the secondary key tuple, a point primary key … during these benchmark runs and that the disks are 4 5.4K disks in Software RAID5. Also note that … n_name, c_address, c_comment order by revenue desc LIMIT 20; In-memory workload Now let’s see how …
Post: MySQL Limitations Part 4: One thread per connection
October 27, 2010 By 14 Comments
… in a series on what’s seriously limiting MySQL in core use cases (links: part 1, 2, 3). This post is about… binary log, which are two major limitations. And it has subqueries, which are a core, fundamental part of SQL — but it’s bad at certain kinds of them. That’s why I listed those as major limitations…
Post: MySQL Limitations Part 3: Subqueries
October 25, 2010 By 20 Comments
… third in a series on what’s seriously limiting MySQL in certain circumstances (links: part 1, 2). This post is about subqueries… a limitation. But it would be a big improvement if it were fixed. See if you can guess what limitation number 4 will…
Comment: Impact of the number of idle connections in MySQL
December 17, 2010 By 20 Comments
… mentioned in http://www.mysqlperformanceblog.com/2010/10/27/mysql-limitations-part-4-one-thread-per-connection/ (thanks Yves for providing the proof…
Post: InnoDB vs MyISAM vs Falcon benchmarks - part 1
January 8, 2007 By 117 Comments
… retrieve rows (more details with Jim Starkey’s comments in Part 2). There MyISAM shows bad scalability with increasing count of… LIMIT queries will be fixed before release. MyISAM shows stable result. InnoDB is better than MyISAM by 58% in case with 4… but with LIMIT. Again the LIMIT is bad for Falcon. InnoDB is better than MyISAM by 87% in case with 4 threads but…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
…, adding LIMIT 0 to the SELECT part of the…limit 10; +——+————-+————-+————-+ | rank | customer_id | total_price | total_lines | +——+————-+————-+————-+ | 1 | 689 | 770793 | 3811 | | 2 | 6543 | 754138 | 3740 | | 3 | 5337 | 742034 | 3674 | | 4…
Post: MySQL-Memcached or NOSQL Tokyo Tyrant - part 3
October 19, 2009 By 25 Comments
… performance with memcached on top of MySQL, in Part 2 we talked about running 100% outside the …at some scalability benchmarks, my server resources are rather limited but I thought I should try throwing more …, memached was started with 16 threads ( 1.4 memcached ), mysql was 5.1 XtraDB. Each …
Post: Tokyo Tyrant -The Extras Part III : Write Bottleneck
November 12, 2009 By 3 Comments
… part 3 of my Tyrant extra’s, part 1 focused on durability, part 2 focused on the perceived performance wall. …per second.   Compare this to 4 Million rows using 4 threads which averaged 40933.86 and you… multiple tables each with there own cache. This limit is per TC DB so this should work. …
Post: MySQL EXPLAIN limits and errors.
July 24, 2006 By 6 Comments
…instead plan is generated as a part of query execution, sometimes being… mysql> explain select * from lt limit 10; +—-+————-+——-+——-+—————+———+———+——+——+————-+ | id | select_type | table | type | …The other thing – since MySQL 4.1 sorting can be …
