… “zero”, and a nonexistent query can’t be bad. Queries, or groups of queries, are bad because they are slow and provide a bad… been available in MySQL for years. This is necessary for determining whether a group of queries completed in a cluster. One-second granularity (what you get in standard MySQL) might be enough precision for finding some cases of queries…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 139 Comments
… completely disk bound can be very slow. One of the reasons elevating this problem in MySQL is lack of advanced join methods… sets. In 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…
Post: MySQL Binaries Percona build10
December 11, 2008 By 12 Comments
… runtime. Next variables were added: | slow_query_log | ON | | slow_query_log_file | /var/lib/mysql/slow_query.log | for compatibility with MySQL 5.1 and | userstat_running… | 1.0 | Jeremy Cole | N/A | | | innodb_io_patches.patch | Cluster of past InnoDB IO patches | 1.0 | Percona | GPL | This…
Post: Database problems in MySQL/PHP Applications
August 11, 2006 By 12 Comments
…clustering so table becomes hot very quickly due to data locality once this user starts his queries…etc. Read more in my Why MySQL Could be slow with Large Tables article. 5. The…queries, especially if you see them in slow query log. If you have trouble understanding EXPLAIN or optimizing your queries…
Post: Percona Server 5.5.16-22.0
October 16, 2011 By 2 Comments
…and from the Percona Software Repositories). Based on MySQL 5.5.16, including all the bug fixes…on non-nullable columns was picked as the clustered index by InnoDB in the absence of a… The Slow Query Log did not log the error number correctly. #830199 (Oleg Tsarev). Variable log-slow-admin-statements…
Post: All thouse new MySQL Storage Engines
April 17, 2008 By 8 Comments
MySQL Users Conference 2008 has number of Storage Engines presented which … also need to make sure they do not break or slow down other features your application use. For example you may… primary key lookups and MySQL Cluster promises good performance and scalability. But if at the same time you have queries with complex Joins…
Comment: Database problems in MySQL/PHP Applications
August 11, 2006 By 12 Comments
…on this completely because InnoDB uses a clustered index based on (in order) the primary…etc. Read more in my > Why MySQL Could be slow with Large Tables article. Deciding …queries, especially > if you see them in slow query log. If you have trouble understanding > EXPLAIN or optimizing your queries…
Post: Commodity Hardware, Commodity Software and Commodity People
June 15, 2007 By 9 Comments
… solution for absolute beginner. Now from queries design MySQL would support a lot of functions (which… great MySQL Expert but have no experience with MySQL Cluster, other may be good with MySQL Cluster but have… also why old products become feature overkill, slow and complicated. I’m not in positions…
Post: The perils of uniform hardware and RAID auto-learn cycles
November 16, 2010 By 16 Comments
… selected machines on a large cluster of quite uniform database servers. Some of the servers were slowing down in a very puzzling way over a short time span (a couple of hours). Queries were taking… some threshold. I’ve seen this before — for example, a query cache bottleneck, or an insert buffer bottleneck, or any of…
Post: Introducing our Percona Live speakers
May 10, 2011 By 4 Comments
… speakers, which is why it has been a slow process to finalize and get abstracts on the web… about using MySQL to find the top N most important rows per group of rows, distributed across a cluster …temp tables and filesorts and multiple queries and all sorts of things in MySQL — and that’s just for …
