… card, not Virident, but there’s a comparison in TPCC-MySQL performance between that card and a traditional SSD – the PCIe… Facebook FlashCache. I’d never even heard of the STEC caching solution prior to your comment. Maybe another Perconian will have…
Comment: The write cache: Swap insanity tome III
April 20, 2013 By 5 Comments
Nice write up. I’m not clear what was being swapped out starting at 10:03:36… Is Linux swapping out mysql malloc’d memory to make room for all those dirty buffers in the write cache?
Comment: Why MySQL Performance at Low Concurrency is Important
March 31, 2013 By 8 Comments
Some results at http://mysqlha.blogspot.com/2013/03/mysql-56-single-threaded-read-only.html. All of the conclusions … a big win * 5.6 was ~9% slower for a cached database whether or not the PS was disabled
Post: Cache Performance Comparison
August 9, 2006 By 74 Comments
… are: Cache Type Cache Gets/sec Array Cache 365000 APC Cache 98000 File Cache 27000 Memcached Cache (TCP/IP) 12200 MySQL Query Cache (TCP/IP) 9900 MySQL Query Cache (Unix… file cache to work you need file named “test” containing “MyTestString” 2) You need to create table test.test for MySQL Cache to…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 64 Comments
… you think about Core idea of the MySQL Query Cache – it is great. The transparent cache which does not require any extra handling… MySQL Query Cache so it once again is appealing to improve performance for MySQL Applications ? Make it Lockless Can we re-implement MySQL Query Cache… rows used from query syntax may be hard. Query Cache Storage Engines MySQL Query Cache now stores queries in local memory, which is…
Post: MySQL caching methods and tips
April 4, 2011 By 5 Comments
… some of the most common cache methods for MySQL. Popular cache methods The MySQL query cache When the query cache is enabled, MySQL examines each query to see if the contents have been stored in the query cache… you need Both Memcached and the MySQL query cache are limited in size. If you try to cache more information than you can…
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
…_SCHEMA_MAX_THREAD_INSTANCES | 1000 | 224 | | SOCKET | /tmp/mysql_sandbox5530.sock | /tmp/mysql_sandbox5610.sock | | INNODB_FILE_PER_TABLE | OFF | ON | | SYNC… now. The query_cache_type is now off by default with default size of 1MB while in MySQL 5.5 and before it was “ON” by default with query cache size of 0 which…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
…: http://bugs.mysql.com/bug.php?id=67647 Metadata locking behaves differently for queries that are serviced from the Query Cache, let… in the Table Cache, any query to a table that has a DDL operation waiting, will block. Why? Because MySQL sees that the old entries in the Table Cache have to be invalidated, and any…
Post: Query Profiling with MySQL: Bypassing caches
September 12, 2007 By 6 Comments
… simple – because SQL_NO_CACHE only bypasses query cache but it has no change on other caches, which are MySQL Caches – Innodb Buffer Pool and… more important SAN caches which can be pretty big. So How can you bypass these caches? For MySQL Caches you can restart MySQL and this is the only way to clean all of the caches. You can…
Post: Write contentions on the query cache
September 5, 2012 By 5 Comments
… 160ms). Of course, I wanted to know more about how MySQL executes this query. So I used commands you’re probably…: why did MySQL need so many accesses to the query cache lock? The answer is in the way the query cache works. Simply…. It means that around 50 accesses to the query cache were needed to cache the entire result set. This is what SHOW…
