… is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though fixing these does help in many… push concurrency too high Many developers will test script with multiple level of concurrency and find out doing work from 32… even single process overloads system too much in this case throttling by having relatively short queries and introducing “sleeps” between them can…
Post: MariaDB 5.3 is released as GA!
March 5, 2012 By 17 Comments
…enabled Faster queries through speedier joins, faster subqueries, and elimination of useless tables in joins Thread…, improvements to partitioning, and the addition of multiple InnoDB buffer pools. Best of all, …of MySQL users.” Well, that dream has come true, and now we have subqueries that execute …
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 …into multiple files (for each shard, for later loading) or it can load files directly, in parallel, to multiple hosts. Shard-Query will execute queries in …
Post: What would make MySQL Multiple Queries Usable ?
September 5, 2007 By 1 Comment
… in most cases. What would make MySQL Multiple Queries API more usable ? Allow to run queries in parallel – The great benefit of knowning all queries…in MySQL any time soon – this would require very significant optimizer and execution engine changes to optimize for set of queries and to execute query…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
…in terms of execution time) of the query on which the view is based. The SQL features used in the query…in multiple transactions. After each transaction it must wait for FlexCDC to process changes from that transaction. In…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 63 Comments
…from query cache and there are multiple connection requesting the same item. What MySQL will do ? It will allow all of them to execute…complex expensive queries, for which tracking exact rows used from query syntax may be hard. Query Cache Storage Engines MySQL Query Cache now stores queries in local…
Post: Is your MySQL Application having Busy IO by Oracle Measures ?
January 8, 2012 By 1 Comment
… MySQL as MySQL optimizer with its nested loops joins does not favor sequential scans even for analytic queries executions. Also lack of parallel query execution… with multiple MySQL instances on powerful storage. When you move to multiple instances and you have to “shard” your data in some …
Post: Using UNION to implement loose index scan in MySQL
August 10, 2006 By 15 Comments
… So MySQL Will not use indexes in all cases when it is technically possible. For multiple key part indexes MySQL will …| 888ba838661aff00bbbce114a2a22423 | +———————————-+ 2 rows in set (0.09 sec) Ethen though this query looks much more complicated MySQL is able to execute it …
Post: Optimizing repeated subexpressions in MySQL
January 23, 2009 By 11 Comments
…MySQL…execute the query 500 times and redirect the results to /dev/null. Results: 31s wall-clock time. The following is an alternative query…query runs 500 iterations in 12s. So it looks like the optimizer was computing the SUM() 18 times in the first query… ordinary multiplication made the query …
Post: MySQL Prepared Statements
August 2, 2006 By 19 Comments
… most of the time in this case. It could also reduce performance in certain cases because if you execute query only once extra round… from same connection or multiple connections. Do not forget to close prepared statements – Many memory leaks reported in MySQL Server turned out to…
