… which were released in MySQL 5.0 without consistent work with MySQL close Partner – Innobase to ensure Group Commit still works in 5.0… a lot. In my Early years in MySQL I have created more than hundred of such little projects suggested by MySQL customers and myself… straighten up this process so good patches can quickly appear in community tree. Once this is done I think amount of contributions…
Post: MySQL EXPLAIN limits and errors.
July 24, 2006 By 6 Comments
… only This is in works to be fixed in some of next version but it is so as of MySQL 5.0 The… long time In MySQL 5.0 with addition of greedy join the problem on looking at too many table join combinations in joins… used in queries. In general in my opinion EXPLAIN needs serious overhaul so it can be used with GUI tool to provide tree like…
Post: Sysbench with support of multi-tables workload
April 29, 2011 By 4 Comments
… used only single table). It is available from launchpad source tree lp:sysbench . This is set of LUA scripts for sysbench…), in this case N sbtest tables will be used. Additional parameter –oltp-secondary is taken from Mark Callaghan’s sysbench tree , in this… we have N tables, we may want to prepare them in parallel, to save some time for preparation I implemented that…
Post: MySQL End Of Life (EOL) Policy
August 22, 2008 By 6 Comments
… as of MySQL 4.1 are followed we’ll soon see stop in MySQL community releases of MySQL 5.0 most likely before MySQL 5.1 will proven MySQL 5.0 replacement. There is no blame on MySQL… trees and backport fixes from the newer releases if MySQL has chosen not to backport bug because of its severity. We believe in…
Post: TPC-H Run on MySQL 5.1 and 6.0
April 10, 2008 By 16 Comments
… queries, in particular those presented in TPC-H benchmark are still subpar even with changes which are currently seen in MySQL 6.0 tree. There is a long way till Release and may be MySQL 6.0 performance will improve. Though considering a lot of talks about optimizer improvements in MySQL 6.0 I…
Post: When EXPLAIN estimates can go wrong!
October 13, 2011 By 7 Comments
… of rows reported by MySQL in the output of EXPLAIN. Now this can be a real pain as MySQL uses “the number of… a bug in MySQL 5.1 and how it calculates the row estimates. This bug was tracked down to http://bugs.mysql.com… estimation, and make the estimation very precise if the index tree is not much wide.
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 28 Comments
… in terms of counters you can get from SHOW GLOBAL STATUS. I’ll start out by copying and pasting from the MySQL…, but seems reasonable based on the structure of a B-tree index, so let’s assume anyway: Hard-to-prove assumption… no good instrumentation in MySQL to guide your decisions. It is also not the be-all and end-all of MySQL performance, and…
Post: Getting MySQL to use full key length
January 31, 2007 By 5 Comments
There is one bug, or “missing feature” in MySQL Optimizer which may give you hard time causing performance problems … do you force MySQL optimizer to use full length in this case ? ANALYZE TABLE does not help, at least in this case. However… the first query should not be smaller. Stats and B-Tree dives can give information which is quite far away from…
Post: Binaries of MySQL 5.0.33 Community release for AMD64 / EM64T
January 12, 2007 By 37 Comments
… yet, coming of the same tree as MySQL Enterprise. To help those who would like to use MySQL Community version but does not…, the server built with our microslow patch, which enables microsecound in slow-log. More info about the patch http://www.mysqlperformanceblog…-tools/ http://bugs.mysql.com/bug.php?id=25412 Also we propose Linux (AMD64 / Intel EM64T) binaries in tar.gz archive (Link…
Post: Dynamic row format for MEMORY tables
September 6, 2011 By 5 Comments
… CHAR. The lack of these features in the MEMORY storage engine (also known as HEAP) in MySQL has been one of the long… 5.6 development tree as of last week. There have been efforts in the community to remove this limitation. In 2008 Igor Chernyshev… keep in mind when using this new feature (and these points are probably the reason why it was not included in MySQL in 2008…
