… available here and from the Percona Software Repositories). Based on MySQL 5.5.22, including all the bug fixes in it… Launchpad. Bugs Fixed: While running the test case found that MEMORY engine may return rows in non-deterministic order for equal keys…
Post: Benchmarking single-row insert performance on Amazon EC2
May 16, 2012 By 11 Comments
…memory available, and memory is what really really matters. High-Memory Quadruple Extra Large Instance 68.4 GB of memory… to the MySQL configuration. MySQL Configuration I used…ENGINE = InnoDB, PARTITION p8 VALUES LESS THAN (900000000) ENGINE = InnoDB, PARTITION p9 VALUES LESS THAN (1000000000) ENGINE…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…MySQL in wild. I also wanted to share some troubleshooting techniques I use. Plot Memory Usage First I would like to see MySQL memory…memory is being used by current MEMORY tables: mysql> select sum(data_length+index_length) from information_schema.tables where engine=’memory‘; …
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
…batched together and sent to the storage engine. The storage engine then uses the MRR interface (which …the workload fits entirely in memory. For the purpose of benchmarking in-memory workload, the InnoDB buffer …at the status counters. Counter Name MySQL 5.5 MySQL 5.6 MySQL 5.6 w/ join_buffer_size=…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
… MySQL 5.6, when the workload fits entirely in memory, because there is no extra cost for memory access at random locations versus memory… lookups are performed in a single call to the storage engine and the counters Handler_read_key and Innodb_rows_read…-memory, in fact MRR adds extra sorting overhead which means that the queries are just a bit slower as compared to MySQL…
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…
Post: Dynamic row format for MEMORY tables
September 6, 2011 By 3 Comments
…. The lack of these features in the MEMORY storage engine (also known as HEAP) in MySQL has been one of the long-standing… in the documentation. What of course interests us is the MEMORY engine performance with this feature added. For that we run a…_INCREMENT, c VARCHAR(4096) NOT NULL DEFAULT ”, PRIMARY KEY (id)) ENGINE=MEMORY ROW_FORMAT=DYNAMIC DEFAULT CHARSET=latin1; Also we modify the…
Post: Power of MySQL Storage Engines
March 5, 2007 By 3 Comments
Where does real power of MySQL Storage Engines, and pluggable storage engines as MySQL 5.1 lays ? It is very much advertised this allows… core storage engines and are not match of functions which you’d find in Oracle, PostgreSQL and other databases. MEMORY storage engine is old timer of this type, ARCHIVE, CSV are other good examples. There are also storage engines out where…
Post: Performance gotcha of MySQL memory tables
February 1, 2008 By 5 Comments
… performance gotcha with MEMORY tables you might know about comes from the fact it is the only MySQL storage engine which defaults to…` tinyint(4) default NULL, PRIMARY KEY (`id`), KEY `c` (`c`) ) ENGINE=MEMORY and populated it with 1.000.000 rows ALL of… could delay writes and do all the changes directly in memory. MyISAM however had to perform number of random writes to…
Post: The Doom of Multiple Storage Engines
May 8, 2010 By 22 Comments
… In Memory storage engines vs Distributed ones. Trying to handle all different cases in Optimizer – such as in memory nature of MEMORY storage engine, clustering… run for different storage engines, but really this is not enough as MySQL allows you using multiple storage engines in the query you…
