… lookups are performed on table2. Of course this could mean a lot of random lookups… status counters. Counter Name MySQL 5.5 MySQL 5.6 MySQL 5.6 w/ join_buffer… Innodb_buffer_pool_reads and Innodb_data_read. We can see that with…to run tests to see what specific types of queries would benefit from Hash…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…of point primary key lookups, a range lookup is performed on the primary key …performing the benchmark on IO bound workload, mentioned above. Counter Name MySQL 5.5 MySQL 5.6 MySQL… 1.89G 1.53G Innodb_data_reads 120552 123872 100551 103011…a. Bad Plan id select_type table type possible_keys key key_len…
Post: Cache Performance Comparison
August 9, 2006 By 73 Comments
… type of caching is rather helpful for some of applications, which tend to access same data read from database multiple times. Examining MySQL… was selecting from MySQL table. Query vas very simple – lookup by primary cache, so this is kind of peak performance MySQL can provide. Of…
Post: MySQL-Memcached or NOSQL Tokyo Tyrant - part 1
October 15, 2009 By 16 Comments
…do you maintain your performance in the face of increasing data size? Here …people use this type of system as I run into this type of application… I can then compare using MySQL to using MySQL + Memcached, and then to …really boost performance. I know you’re thinking my simple key lookup should really …
Post: How adding another table to JOIN can improve performance ?
August 1, 2008 By 12 Comments
…very typical reporting query which queries data for date range for multiple of … same time ? Performing such query MySQL has to build (and do lookups) for all combinations… 2. row *************************** id: 1 select_type: SIMPLE table: g type: index possible_keys: PRIMARY key: …
Post: The MySQL optimizer, the OS cache, and sequential versus random I/O
April 28, 2008 By 17 Comments
…Data_length: 17217646764 Index_length: 11993816064 mysql…performing index lookups into the fact table, which is big. An index lookup… | table | type | rows | Extra | +——-+———–+———–+———————————+ | fact | …
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 139 Comments
…you have your data fully in memory you could perform over 300.000 of random lookups per second … large data sets. In MySQL single query runs as single thread (with exeption of MySQL Cluster) and MySQL… large data sets full table scans are often faster than range scans and other types of index lookups….
Post: 3 ways MySQL uses indexes
September 12, 2009 By 27 Comments
…MySQL can use indexing, getting wrong ideas on what query performance they should expect. There are 3 main ways how MySQL…data set. This is most typical reason index gets added on the first place. Most popular index type in MySQL… parts are actually used for row lookup. Very common problem I see is …
Post: MySQL Query Cache
July 27, 2006 By 69 Comments
…MySQL Performance optimization tasks but there are number of things you need to know. First let me clarify what MySQL…more reason for high performance is Query Cache performs query lookup in the …you can set query_cache_type to “DEMAND” and use… copies of the same data in cache effectively wasting …
Post: ORDER BY ... LIMIT Performance Optimization
September 1, 2006 By 93 Comments
…cause of MySQL Performance problems….large data sets … | id | select_type | table | type | possible_keys | key…MySQL Optimizer does not have to chose between better sort or better lookup…
