…use reasonable global buffers, such as innodb_buffer_size, key_buffer_size etc, you have reasonable amount of connections but yet MySQL takes much more memory… how many user variables are allocated (and how much memory they use). Memory Tables MEMORY tables can take memory. There are implicit MEMORY …
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
…much of a difference to in-memory workload. Also BKA relies on both the join_buffer_size and the read_rnd_buffer_size/mrr_buffer_size…buffer_size/mrr_buffer_size because these have an impact on MRR performance, and BKA uses the MRR interface, so these buffers…
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: How much memory can MySQL use in the worst case?
February 12, 2009 By 17 Comments
…that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_connections”. …key. Note how long it took to run these statements! And now mysqld is suddenly using 324M of memory…much, in my opinion. I think it’s far better to use a monitoring tool to watch the actual memory…
Post: How much memory Innodb locks really take ?
July 13, 2006 By 11 Comments
…lock table, located in the buffer pool where small record …` varchar(255) default NULL, PRIMARY KEY (`i`), KEY `j` (`j`) ) ENGINE=InnoDB…systems. So we have tested how much memory is using locking all the rows …size 44352 So we locked over 100K rows using about 44KB. This is still quite efficient using…
Post: How much overhead is caused by on disk temporary tables
August 16, 2007 By 26 Comments
… to see how much overhead do on disk temporary tables cause compared to MEMORY tables. To have things comparable I used medium size table and…. OK. Now lets move to testing MEMORY tables for the same queries: mysql> set global key_buffer_size=8000000; Query OK, 0 rows affected…
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 27 Comments
… time information you’re lacking is how much time each buffer hit or miss takes. If you…memory based on how important those tables are to you, how big the indexes are on disk, and so on. Raise the key_buffer_size… and use it as a heuristic for how big your working set is. Set the key_buffer_size to …
Post: MySQL Server Memory Usage
May 17, 2006 By 18 Comments
…key_buffer_size, innodb_buffer_pool_size, innodb_additional_memory_pool_size, innodb_log_buffer_size, query_cache_size. If you’re using MyISAM seriously you can also add the size…much as read_buffer_size, sort_buffer_size, read_rnd_buffer_size, tmp_table_size of memory…
Post: Choosing innodb_buffer_pool_size
November 3, 2007 By 38 Comments
…size you need to check if there are any restrictions on Innodb Buffer Size you can use…How Much Memory do you need for other needs. This needs would be OS needs – your system processes, page tables, socket buffers…
Post: Predicting how long data load would take
May 24, 2007 By 12 Comments
…size increase myisam_sort_buffer_size or key_buffer_size increase. Innodb typically needs large innodb_buffer_pool_size and large innodb_log_file_size…how much data is loaded per hour (assuming your Innodb tablespace did not have free space or you’re using…
