… SHOW STATUS LIKE ‘Handler%’ with the SQL_NO_CACHE hint. Will the output be different without SQL_NO_CACHE? Indeed it was. If the Handler… for query cache lock | 0.000004 | | Waiting on query cache mutex | 0.000002 | | Sending data | 0.003407 | | Waiting for query cache lock | 0.000003 | | Waiting on query cache… was: why did MySQL need so many accesses to the query cache lock? The answer is in the way the query cache works. Simply stated…
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
…NO_CACHE to block caching for certain queries, which you know do not need to be cached. Counting query cache…query cache. Now lets speak a bit about Query Cache configuration and mainance. MySQL Manual is pretty good on this: Query Cache Query Cache Status Query Cache…
Post: New SpecJAppServer results at MySQL and Sun.
November 12, 2008 By Leave a Comment
… from such benchmarks there is no direct comparison available. The configuration… some hints what you can try for JDBC configuration. Some caching options …cache = 16 query_cache_size = 0M thread_concurrency = 8 max_heap_table_size=200M log-output = FILE log-slow-queries=/tmp/mysql-slow.log long_query…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… 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…
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
… fail. To give you couple of hints: Temporary Tables You can build query (with derived tables) which uses … to take up all memory. However there is no per user limit so one user can consume …IO system and wipe off both MySQL and OS caches which can cause other users queries to perform order of …
Post: Read/Write Splitting with PHP Webinar Questions Followup
January 23, 2013 By 4 Comments
…No slave is chosen more than once. If no slaves pass the tolerance test, then the wrapper class executes the query… my prototype to use hints embedded in SQL comments, …MySQL database for persistence, but when we measured query load with pt-query… with using a write-through cache? A: The InnoDB buffer…
Post: Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
…cc patching file sql/sql_cache.cc patching file sql/…hints about installing MySQL on your platform. Also have a look at the files in the Docs directory. Thank you for choosing MySQL…query_time microseconds to execute to file. This option is standard MySQL, however after you apply the patch, it will no…
Post: When the subselect runs faster
March 18, 2010 By 9 Comments
… does not fit in cache well) When you want to run this query mysql first will try … the query – use index to find rows. This is sensible strategy if there is no LIMIT, …MySQL check WHERE clause while scanning table in index order. We can just use FORCE INDEX hint to override MySQL index choice: mysql…
