One of the very frequent cases with performance problems with MySQL is what they happen every so often or certain times… need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though…
Comment: Multi Column indexes vs Index Merge
May 10, 2012 By 30 Comments
…secs. I dont understand why MySQL uses index merge after a… LIMIT 505 ; …
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…_heap_table_size variable which allows you to limit size of MEMORY tables (the limit applies both to implicit and explicit ones… have created which temporary tables (both in memory and not): mysql> select * from information_schema.global_temporary_tables \G *************************** 1. row… and fixed. This is where your MySQL Support contract can be handy. Conclusion Understanding where MySQL can allocate memory can help us…
Post: Percona Live MySQL Conference & Expo Was A Great Event
April 17, 2012 By 2 Comments
… that were available. In 2013 we have none of those limitations: the conference is a day longer and isn’t scheduled… Oracle for their new development milestone release for MySQL 5.6, released on Monday. MySQL 5.6 just keeps looking better and… also recorded some of the breakout sessions, so watch Planet MySQL for an announcement when she posts those online. Presentation slides…
Post: Joining many tables in MySQL - optimizer_search_depth
April 20, 2012 By 6 Comments
… further I found the following explanation from Timour Katchaounov in MySQL mailing list archives I have some recollection that there were… – it picks value of min(number of tables, 7) essentially limiting search depth to no more than 7 at which complexity… plan computation would be more important than backward compatibility. In MySQL 5.6 things are likely to get even better handling…
Post: BOFs and Lightning Talks Announced for Percona Live MySQL Conference & Expo
March 22, 2012 By Leave a Comment
… miss out on this great opportunity to connect with the MySQL community at the largest community gathering in the world. To… weeks from now, we are pleased to make a special, limited time offer. Register between Thursday March 22nd and midnight PDT… One of five copies of the new book High Performance MySQL, 3rd Edition Don’t miss this special offer – register now…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a… optimizer enhancement Index Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take…. Index Condition Pushdown Traditional B-Tree index lookups have some limitations in cases such as range scans, where index parts after…
Post: Percona Toolkit 2.1 with New Online Schema Change Tool
April 5, 2012 By 9 Comments
…. Percona Toolkit is the essential suite of administrative tools for MySQL. With this release we introduce a new version of pt… tool, one of the most painful things anyone experiences with MySQL is significantly alleviated. If you’ve ever delayed a project… using it eagerly even without advertisement. However, it had many limitations and missing features. The new 2.1 version of the…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
…, o_orderdate, o_shippriority order by revenue desc, o_orderdate LIMIT 10; In-memory workload Now let’s see how effective… 5.5 is quite slow as compared to both MySQL 5.5 and MySQL 5.6. For MariaDB 5.5 the query… a look at the status counters. Counter Name MySQL 5.5 MySQL 5.6 MySQL 5.6 w/ join_buffer_size=6M & read…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…, n_name, c_address, c_comment order by revenue desc LIMIT 20; In-memory workload Now let’s see how effective… on IO bound workload, mentioned above. Counter Name MySQL 5.5 MySQL 5.6 MySQL 5.6 w/ read_rnd_bufer_size=4M…, there is no difference in query times between MySQL 5.5 and MySQL 5.6/MariaDB 5.5 This is another area…
