…post: single SELECT queries doing PRIMARY KEY lookups (aka QPS sysbench mode); same MySQL queries executed inside single-statement transactions (TPS mode… –max-time=120 –max-requests=0 –percentile=99 –mysql-user=root –mysql-db=sbtest8t1M –mysql-table-engine=INNODB –mysql-socket=/tmp/mysql.sock…
Post: trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2
April 12, 2013 By 3 Comments
…transactions, while a great optimization in itself, applies only to the following kinds of transactions: MySQL transactions started with START TRANSACTION READ ONLY MySQL transactions…queries wrapped into regular (i.e. not marked as read-only) transactions. In this case MySQL…
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
… ’0′, PRIMARY KEY (`hid`,`mid`,`id`) ) and transactions are: $HID=rand(0,10000) // distributed by uniform… –mysql-user=root –oltp-tables-count=32 –mysql_table_engine=tokudb –oltp_auto_inc=on –max-time=18000… = 4M thread_cache_size = 1000 query_cache_size = 0 query_cache_type = 0 ft_min_word_len =…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
… exact same pattern when looking at transaction latency; the baseline numbers are … –max-time=7200 –max-requests=0 –percentile=95 \ –mysql-user=root –mysql-socket=/tmp/mysql.sock –mysql-table-engine=…4M thread_cache_size = 1000 query_cache_size = 0 query_cache_type = 0 ft_min_…
Comment: SimCity outages, traffic control and Thread Pool for MySQL
March 21, 2013 By 16 Comments
….5.x clusters with not just simple queries or simple transactions but high concurrency with complex transactions as well — items like the thread pool offering far more sanity and stability than life back in the days of MySQL…/building-a-mysql-private-cloud-step-1/ — this will be a series of posts over time (as I have spare time for non…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 20 Comments
…computes changes in multiple transactions. After each transaction it must wait for FlexCDC to process changes from that transaction. In practice, this …of time: mysql> call flexviews.enable( -> flexviews.get_id(‘demo’,'complete_example2′)); Query OK, 0 rows affected (42 min 42.14 sec) mysql> call…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…time_formatblogpercona.commanual time_zoneblogpercona.commanual timed_mutexesblogpercona.commanual timestampblogpercona.commanual tmp_table_sizeblogpercona.commanual tmpdirblogpercona.commanual transaction_alloc_block_sizeblogpercona.commanual transaction_isolationblogpercona.commanual transaction…
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
… being confused, thinking MySQL Query Cache is the same as Oracle Query Cache – meaning cache where execution plans are cached. MySQL Query Cache is not… transaction you have best chance for them to be cached. Query must be deterministic – Query might provide same result no matter how many times…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
… query ? You can take a look at procfs for MySQL process: root@ubuntu:/var/log/mysql…_TRANSACTIONS: 181243 ROLLBACK_TRANSACTIONS: 0 DENIED_CONNECTIONS: 0 LOST_CONNECTIONS: 0 ACCESS_DENIED: 0 EMPTY_QUERIES…The query time distribution histogram is also very interesting here we can see this query which …
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
… Locking behavior prior to MySQL 5.5.3 Metadata Locking behavior prior to MySQL 5.5.3 Prior to MySQL 5.5.3… not the end of the transaction. This meant that transaction was not really isolated, because the same query could return different results if… time when the ALTER is waiting for metadata locks. Let’s see this in action via another test case: session1 > start transaction; Query…
