June 19, 2013

Post: MySQL Query Patterns, Optimized - Webinar questions followup

June 3, 2013 By 2 Comments

… Can you compare the use of subqueries/multiple joins vs. multiple queries (e.g. temp tables)? For performance, … queries against the temp table fail. Q: Why doesn’t the query optimizer take care the execution … in this case to force MySQL to scan the `title` table first, grouping by kind_id in index …

Filed Under: Insight for Developers, MySQL, MySQL Webinars Tagged With: , , ,

Post: Choosing a MySQL HA Solution - Post-Webinar Q&A

June 7, 2013 By Leave a Comment

…in balance-rr mode; this is the only NIC bonding mode which will allow you to stripe a TCP connection over multiple…filters are executed on the intermediate server, thus resulting in less…queries in the output of SHOW PROCESSLIST that might be a sign that trouble is brewing. Or if you watch your MySQL…

Filed Under: Insight for DBAs, Insight for Developers, MySQL, MySQL Webinars Tagged With: , , ,

Post: Why MySQL Performance at Low Concurrency is Important

March 27, 2013 By 8 Comments

… baseline that offers the best response times (MySQL server does not use multiple threads to execute query in parallel at this point). Response times at… cases in which single-thread execution is what is going to happen — many batch jobs are written to be single-threaded. MySQL replication…

Filed Under: Benchmarks, MySQL, Percona Live Tagged With: , , , , , ,

Post: Wow. My 6 year old MySQL Bug is finally fixed in MySQL 5.6

August 30, 2012 By 2 Comments

… look at query execution: | Handler_read_next | 1305742982 | mysql> select count(*) from trunc where i=4147483647; +———-+ | count(*) | +———-+ | 0 | +———-+ 1 row in set, … performed I came across the bug in the real application which would use multiple table and the column type was …

Filed Under: Insight for DBAs, MySQL

Post: Shard-Query turbo charges Infobright community edition (ICE)

May 6, 2011 By 23 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 …

Filed Under: MySQL

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…

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Post: Flexviews - part 3 - improving query performance using materialized views

April 4, 2011 By 20 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…

Filed Under: Insight for DBAs, MySQL

Post: Should we give a MySQL Query Cache a second chance ?

April 10, 2011 By 64 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…

Filed Under: Insight for DBAs, MySQL

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 …

Filed Under: Hardware and Storage, Insight for DBAs, MySQL

Post: InnoDB Full-text Search in MySQL 5.6 (part 1)

February 26, 2013 By 1 Comment

… search in MySQL 5.6 (part 1) in MySQL 5.6 is syntactically identical to MyISAM full-text search, in the …, it’s entirely possible to DROP multiple FT indexes with InnoDB in the same ALTER TABLE statement, but …, and each execution took between 6 and 8 seconds, but the output of the query against I_S….

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