…_file_per_table = 1 ## Disabling query cache query_cache_size = 0 query_cache_type = 0 You can see…` float NOT NULL, PRIMARY KEY (`transactionid`), KEY `marketsegment` (`price`,`customerid`), KEY `registersegment` (`cashregisterid`,`price`,`customerid`), KEY `pdc` (`price`,`dateandtime`,`customerid`)…
Post: MariaDB 5.3 is released as GA!
March 5, 2012 By 17 Comments
… of useless tables in joins Thread pooling and a segmented key cache for improved scalability That’s really just a sampling. A…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
…_keys=on’ optimizer_switch=’mrr_cost_based=off’ optimizer_switch=’join_cache_incremental=on’ optimizer_switch=’join_cache_hashed=on’ optimizer_switch=’join_cache_bka=on’ join_cache_level=8 join_buffer…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… for filtering records. For example, suppose you have a key defined as: KEY `i_l_partkey` (`l_partkey`,`l_quantity`,`l_shipmode…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
… MySQL 5.6 and MariaDB 5.5. Note that query cache is disabled during these benchmark runs and that the disks… plans. a. Bad Plan id select_type table type possible_keys key key_len ref rows filtered Extra 1 SIMPLE nation ALL PRIMARY… where b. Good Plan id select_type table type possible_keys key key_len ref rows filtered Extra 1 SIMPLE orders range PRIMARY…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…to use reasonable global buffers, such as innodb_buffer_size, key_buffer_size etc, you have reasonable amount of connections … Adaptive hash index 4422068288 (2039977928 + 2382090360) Page hash 127499384 Dictionary cache 512619219 (509995888 + 2623331) File system 294352 (82672 + 211680) Lock system…
Comment: Too many connections? No problem!
March 15, 2012 By 28 Comments
…-using-indexes query_cache_type=1 query_cache_size=32M thread_cache_size=30 table_cache=4096 join_buffer_size=6M key_buffer_size=12M…
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 27 Comments
… key buffer, key_buffer, and key cache interchangeably. However, I will be careful about the difference between “rate” and “ratio”. In this article, the key cache… “your key cache hit ratio should be very high, ideally above 99.9%” or “if your key cache hit ratio is low, your key_buffer… you think: Server #1 has a key cache miss ratio of 23% Server #2 has a key cache miss ratio of 0.001% Which…
Post: Using Multiple Key Caches for MyISAM Scalability
November 26, 2008 By 8 Comments
… but Key Cache Mutex will still hunt you. If you aware of MySQL history you may think Key Cache scalability was fixed with new Key Cache… use multiple Key Caches to reduce or virtually eliminate key cache contention. Too bad you can only map single table to single key cache – it would be so much more helpful if you could use multiple key caches for the same table, for example caching even/odd key…
Post: Getting annoyed with MyISAM multiple key caches.
May 1, 2009 By 11 Comments
… key cache parameters – via structured variables In particular I would like to: See the list of created caches Right now I can create key caches with random names causing invisible resource consumption. It is possible to make an error in key cache… key caches but there is no way to see the current mappings or to see where each given table is cached. See other key cache…
