… in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a… optimizer enhancement Index Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take… the part on which range condition is applied cannot be used for filtering records. For example, suppose you have a key…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
Post: MySQL Query Cache
July 27, 2006 By 69 Comments
…MySQL Query Cache is the same as Oracle Query Cache – meaning cache where execution plans are cached. MySQL Query Cache is not. It does not cache the plan but full result sets…
Post: Caching techinques
August 8, 2006 By 11 Comments
…caching in files can be very helpful is caching data long term – ie if you got it from some Web Service. For smaller… used by MySQL Query Cache is too coarse invalidating a lot of queries…cache update algorithm which would populate cache with result set for most frequent and complicated queries…
Post: New SpecJAppServer results at MySQL and Sun.
November 12, 2008 By Leave a Comment
…MySQL. These are great results, plus they can be relevant to a lot of us because commodity x86 based hardware was used… them. The MySQL Settings are probably what is the most interesting: MySQL 5.0… smaller sort buffer because allocating it will likely be faster. query_cache_size = 0M – query cache…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…smaller…cache_disk_use | 0 | | Binlog_cache_use | 468 | | Bytes_received | 1708212 | | Bytes_sent | 7796961 | | Com_admin_commands | 11893 | … snip … Then I format the second set…query.) If it’s not possible to use a patched binary, we can use MySQL…
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 27 Comments
…smaller ones. If you make some assumptions that are very hard to prove, there actually is a very limited use…results to your IO system’s capabilities. MySQL doesn’t have good instrumentation for scientifically choosing a key_buffer_size setting…
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
…smaller servers. Table Cache Merge Tables – Table Cache is allocated in entries and it is normally assumed each entry will use…queries. Stored Procedures – How much memory can stored procedure allocate ? say can you create 1000 variables in stored procedure and set 1M result set…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 139 Comments
…is cached or not different selectivity might show benefit from using indexes. In fact even MySQL…query into several, run in parallel and aggregate result sets. So if you’re dealing with large data sets and complex queries… sets using nested loops is very expensive. Try to avoid it. Joins to smaller…
Post: How fast can you sort data with MySQL ?
August 18, 2007 By 26 Comments
…MySQL can sort 1.000.000 rows, or rather return top 10 rows from sorted result set which is the most typical way sorting is used…smaller than even default value. The CPU in question was Pentium 4 having 1024K of cache…
Post: Enum Fields VS Varchar VS Int + Joined table: What is Faster?
January 24, 2008 By 27 Comments
…benchmark which shows MySQL performance when you use 3 different approaches:…words about our data set we’ve used for this benchmark. … because table is significantly smaller with ENUM or …query times longer. 1) Results for ENUM: select SQL_NO_CACHE city, state from cities_enum limit 10000, 5; Result…
