…MySQL is really stupid here, and EXPLAIN for this query took 6 min! If you wonder about carriers – EV is…performance…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
…is that MySQL doesn’t tend to perform…is clearly better for some workloads out-of-the-box than MySQL is, especially for more complex queries. Percona is not tied to MySQL…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 20 Comments
…. Refresh method performance comparison For demonstration purposes, I did the following: Created one view of each type. The view is the same… very long time to refresh: mysql> call flexviews.refresh( -> flexviews.get_id(‘demo’,'complete_example2′),’BOTH’,NULL); Query OK, 0 rows affected…
Post: MySQL 6.0 vs 5.1 in TPC-H queries
March 25, 2008 By 17 Comments
…NULL, `l_commitdate` date NOT NULL, `l_receiptdate` date NOT NULL, `l_shipinstruct` char(25) NOT NULL, `l_comment` varchar(44) NOT NULL… works. What else worth to mention here is that MySQL is wrong choosing index scan here. If…_dt_idx) (full table scan will be performed in this case) then we got: 1…
Post: Talking MySQL to Sphinx
April 19, 2009 By 4 Comments
… search performance, we already know Sphinx is much faster than MySQL build in full text search. I was rather interested to look performance of…sec) MySQL mysql> select max(author_id) as a ,forum_id as f from sptest where num_links=1; +——+—+ | a | f | +——+—+ | NULL | NULL | +——+—+ 1…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
… range scan is performed, but we can see its only incremented in MariaDB 5.5 and not in MySQL 5.6, is that because… performing badly. The interesting thing is that though both MariaDB and MySQL 5.6 are reporting high numbers for Innodb_rows_read, which is…_len ref rows filtered Extra 1 SIMPLE nation ALL PRIMARY NULL NULL NULL 25 100.00 Using temporary; Using filesort 1 SIMPLE customer…
Post: Avoiding auto-increment holes on InnoDB with INSERT IGNORE
November 29, 2011 By 8 Comments
…is needed, increments that counter and assigns the new value to the column. Prior to MySQL… We have recovered the concurrency and the performance but with a small cost. Queries like INSERT…is null; Query OK, 1 row affected (0.00 sec) Insert the same value multiple times. As you will see, the INSERT is…
Post: Is there room for more MySQL IO Optimization?
January 3, 2013 By 11 Comments
…: NULL Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: 1 row in set (0.02 sec) The table is approximately… anything unbuffered performance should be better as it has less overhead with double buffering as well as more information MySQL has about… behavior next. Lets see if situation is dramatically different. The good news though is even though performance advantages of buffered mode can be…
Post: The Optimization That (Often) Isn't: Index Merge Intersection
December 14, 2012 By 6 Comments
… a significant performance win, perhaps. Sometimes it is. Other times, it is a major performance killer. It’s fairly straightforward to tell when MySQL is doing…_id INT UNSIGNED NOT NULL AUTO_INCREMENT, parent_id INT NOT NULL DEFAULT 0, status TINYINT UNSIGNED NOT NULL DEFAULT 0, user_type…
Post: MySQL Partitioning - can save you or kill you
December 11, 2010 By 45 Comments
I wanted for a while to write about using MySQL Partitioning for Performance Optimization and I just got a relevant customer case… NULL, `data` bigint(20) unsigned DEFAULT NULL, PRIMARY KEY (`id`), KEY `uu` (`uu`), ) ENGINE=InnoDB The access pattern to this table is to… would allow replication to perform better when it is now, while selects still performed in the amount system needs. What is a take away…
