… memory (Battery or capacitor-backed write cache), etc., but the principle is basically the… MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL … maintained in separate tables and there also exists a users_groups table to define the relationship…
Comment: MySQL Partitioning - can save you or kill you
April 30, 2013 By 45 Comments
… case — * The entire table is too big to be cached, but * One partition is small enough to be cached, and * Your accesses are… (within a single connection) anywhere in any ‘free’ variant of MySQL. PARTITIONs are scanned one at a time. (Please provide specific… (non-partitioned) table will, at worst, hit the disk only 5 times. (Usually 4 of the 5 are cached from previous queries…
Comment: MySQL 5.6 - InnoDB Memcached Plugin as a caching layer
March 29, 2013 By 10 Comments
… how memcached cache time expiry being apply into MySQL 5.6 memcached. e.g. if i want to store a cache object for… set cache life time as 12hours. Can this apply to the MySQL innodb memcache? i.e. will the cache being delete off innodb table after 12hours or they remain permanent? for doing cache clearing off table…
Comment: MySQL Partitioning - can save you or kill you
April 30, 2013 By 45 Comments
… partitioned table, as, depending on the size of the partitions, the whole partition can be cached, as opposed to a single table, where probably only recently read records will be cached, resulting in more… other column, these could easily be quicker on a partitioned table, as Mysql can fire off one thread per partition (at least…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 64 Comments
… 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… and data about Query Cache content and operation can be presented as some INFORMATION_SCHEMA tables. Self Refresh MySQL Query Cache causes not uniform…
Post: Query Profiling with MySQL: Bypassing caches
September 12, 2007 By 6 Comments
… is also table_cache both MySQL side and Internal Innodb one which can affect query execution speed. OS Caches Operation Systems typically cache file IO… MySQL Caches you can restart MySQL and this is the only way to clean all of the caches. You can do FLUSH TABLES to clean MySQL table cache (but not Innodb table…
Post: table_cache negative scalability
November 16, 2009 By 23 Comments
… was fixed in MySQL 5.1 – in this version table_cache was significantly redone and split in table_open_cache and table_definition_cache and I assumed the behavior may be different as well. MySQL…
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
…thinking 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 … will not be cached. Table level granularity in invalidation – If table gets modification all queries derived from this table are invalidated at …
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
… a table that is already 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 query that accesses the table will have…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
… 60 done Check for Table Cache Related Allocations There are cases when MySQL will allocate a lot of memory for table cache, especially if you… down. What you might see instead is flushing tables regularly or reducing table cache reduces memory consumption to be withing the reason. Connection…
