… like this – you have configured MySQL to use reasonable global buffers, such as innodb_buffer_size, key_buffer_size etc, you have reasonable amount of connections… no control of how many tables application can create it does not really allows to restrict memory usage. For Permanent tables…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…: SELECT key_column, pk_column FROM tbl WHERE key_column=x ORDER BY key_column (Note that secondary keys in InnoDB contain primary key columns) Buffer each pk_column value fetched from step 1, and when the buffer… 2 100.00 Using where So during cold query runs the optimizer would switch to using plan ‘a’, which does not involve MRR…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
… times into the buffer pool. So considering this drawback, Batched Key Access (BKA) optimization was introduced. When BKA is being used then, after… workload, the InnoDB buffer pool size is set to 1G and the buffer pool was not warmed up, so that it does not have… are values for Innodb_buffer_pool_reads and Innodb_data_read. We can see that with appropriately sized buffers less no. of Innodb_buffer_pool_reads…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… condition is applied cannot be used for filtering records. For example, suppose you have a key defined as: KEY `i_l_partkey` (`l…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 17 Comments
…: Does Innodb secondary Indexes trees are allocated in two extents same as primary key tree or stored in the same extent ? HT: An InnoDB… on high IO pressure workloads. Q7: Does Innodb has any protection from pages being overwritten in buffer pool by large full table scan… Inaam. Q19: INNODB uses it’s own internal buffer pool but it’s in conflict with the Linux kernel’s buffer pool. In high…
Post: Improved InnoDB fast index creation
November 6, 2011 By 4 Comments
… constant. The reason is that when using merge sort, InnoDB has to scan the clustered index only…buffer pool. A benchmark is worth a thousand words, so let’s repeat the last test with innodb_buffer… option –innodb-optimize-keys which does just that, i.e. it tries to optimize dumps of InnoDB tables …
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…/child`: , CONSTRAINT `child_ibfk_1` FOREIGN KEY (`parent_id`) REFERENCES `parent` (`id`) ON…used by transaction in question (meaning it was accessed) and number of tables locked by transactions. Innodb does… in log buffer as well as when last checkpoint was performed. Innodb uses fuzzy checkpointing…
Post: My Innodb Feature wishes
May 4, 2006 By 30 Comments
…compression. Insert buffer for delete. For Insert operation Innodb uses nice tecnique called Insert Buffer which speeds up…purged. Long Rows. One ugly thing Innodb currently does is storing first 700 bytes or …is ugly and inconvenient. Having independent CLUSTER=key option would be great, it also …
Post: InnoDB vs MyISAM vs Falcon benchmarks - part 1
January 8, 2007 By 117 Comments
…InnoDB: libexec/mysqld –no-defaults –user=root –key-buffer-size=1500M –innodb-buffer-pool-size=1500M –innodb-log-file-size=100M –innodb…does not scale good enough. Perhaps there is still a problem with InnoDB mutexes. READ_KEY… only to key column and ‘pread’ syscall is not used. READ_KEY_RANGE …
Post: What MySQL buffer cache hit rate should you target
June 29, 2006 By 5 Comments
… typical question I’m asked. It could by MyISAM key_buffer or Innodb innodb_buffer_pool it does not really matter. In both cases trying to… in this case global key hit ratio may be 99.99% but you would still have problems with key buffer efficiency. In the… writes” from SHOW INNODB STATUS for Innodb tables. In MySQL 5.0+ you can also use Innodb_data_reads, and Innodb_data_writes counters from…
