…’s come to the MySQL configuration. MySQL Configuration I used Percona Server…innodb_file_per_table = 1 ## Disabling query cache query_cache_size = 0 query_cache_type =…the table, with each instance of iiBench writing 200 million single row…of the B+tree, having multiple buffer pool instances to reduce…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 63 Comments
…of original implementation which appeared in MySQL 4.0 Query Cache was designed to work with single core systems and relatively small …multiple MySQL Query Cache instances hashed by query hash. It would help to reduce complexity dramatically. Fast Invalidation Right now when you update the table…
Post: Is your MySQL Application having Busy IO by Oracle Measures ?
January 8, 2012 By 1 Comment
… analytic queries executions. Also lack of parallel query execution makes limits how much IO full table scan queries can consume. If we look at single… get a lot better performance with multiple MySQL instances on powerful storage. When you move to multiple instances and you have to “shard…
Post: Moving Subtrees in Closure Table Hierarchies
February 14, 2011 By 7 Comments
… simple case of adding a single new node. When you insert a subtree, you’re inserting multiple nodes, and you want to… target table ‘TreePaths’ for update in FROM clause.” We can’t DELETE and SELECT from the same table in a single query in MySQL. But we can use MySQL‘s multi-table DELETE syntax, to find any…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 22 Comments
… helps improve the performance of queries against a MySQL database by distributing the work over multiple machines and/or multiple cores. This is similar… will be described in another post. Complex queries Shard-Query was tested with the simple single table version of this data set in a…
Post: MySQL caching methods and tips
April 4, 2011 By 4 Comments
… single row in any table, the query cache entries for every query which accessed that table must be invalidated. If a frequently executed or expensive query… the MySQL query cache, since the rate of invalidation can not be controlled, and multiple cache entries may be invalidated by a single table change…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 139 Comments
… MySQL single query runs as single thread (with exeption of MySQL Cluster) and MySQL issues IO requests one by one for query execution, which means if single query execution… multiple servers to host portions of data set. Store portion of data you’re going to work with in temporary table etc…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
…that are based on only a single base table. Knowing this, the query result set is treated as … work, due to the multiple levels of result set reduction. Finally, Shard-Query can automatically partition sets …resource which speaks SQL, but right now only MySQL storage nodes are supported. Amdahl’s law …
Post: The Doom of Multiple Storage Engines
May 8, 2010 By 22 Comments
… as MySQL allows you using multiple storage engines in the query you need to test all kinds of combination such as running multi-table… hot way without nasty “FLUSH TABLE WITH READLOCK” and hoping nobody is touching “mysql” database any more. Single Storage Engine server would be…
Post: Making MySQL Replication Parallel
January 30, 2007 By 1 Comment
…MySQL Replication is single threaded so in reality it is only able to use only single CPU and single…single queries or transactions which do not have any overlap in terms of tables. For some users commit order for independent queries… tables. There is other possible solution it is to allow multiple…
