…solution for randomly choosing rows involves some compromise, either of performance, or of accuracy of randomness. The ORDER BY RAND() …storing another column, and reinitializing the sequence after making certain insert/update/delete operations. If you have a dataset that changes infrequently…
Comment: MySQL Performance Forums
June 9, 2013 By 18 Comments
…. Now during those 300 second, other ‘innocuous’ queries which perform small insert or updates into completely different table (unrelated to the select query) also get hang up. If I do show processlist, the update…
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
… to compare InnoDB performance vs TokuDB. I have a particular workload I’m interested in testing – it is an insert-intensive workload… roll-up aggregation, which should produce updates in-place (I will use INSERT .. ON DUPLICATE KEY UPDATE statements for that), so it will… fast inserts, but it is suitable for range selects by `id`. However it will interesting how both InnoDB and TokuDB performs if…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…, but also updates groups with some metadata: BEGIN; INSERT INTO users_groups (user_id, group_id) VALUES (100, 1); UPDATE groups SET last… besides 1 and suddenly you can update much faster. I see this tuning very frequently for “performance” reasons when data durability isn… table so we don’t need to update the parent group row so often? INSERT INTO users_groups (user_id, group_id…
Comment: Benchmarking Percona Server TokuDB vs InnoDB
May 8, 2013 By 32 Comments
… “insert on dup key update” statements do a point query to read the row. If the row exists, then the row is updated. Otherwise, the row is inserted. TokuDB has an optimization in which the point… can result in dramatic performance increase since the cost of reads is amortized. TokuDB currently detected update expressions like x=x+c…
Comment: MySQL Partitioning - can save you or kill you
April 30, 2013 By 45 Comments
…, performance is not bad. (The last 2-3 partitions tend to stay in the buffer_pool.) If I recall correctly, any INSERT… otherwise.) I would argue that single-row queries (SELECT, INSERT, DELETE, UPDATE) are similar in speed between PARTITIONed or non-PARTITIONed. When… two points. * Secondary indexes are also BTrees, so they need updating (although delayed). Yes, their BTrees may be one level shallower…
Post: Follow these basics when migrating to Percona XtraDB Cluster for MySQL
May 1, 2013 By 10 Comments
…these basics. log_slave_updates is REQUIRED You need to have log_slave_updates enabled on the …the cluster, this is to avoid collisions when INSERTs are happening on not only a single node…. PK imposes an additional overhead, and because cluster performance is somewhat dependent on the slowest node – …
Post: Innodb performance gotcha w Larger queries.
August 28, 2009 By 7 Comments
… looking for a way to improve update performance for the application and I was replacing single value UPDATE with multiple value REPLACE (though… problem with INSERT ON DUPLICATE KEY UPDATE) As I went from 1 value to 3 or 10 in the batch performance improved, especially… is INSERT, and it does not use this function so it did not have a bug. INSERT ON DUPLICATE KEY UPDATE, REPLACE, UPDATE all…
Post: INSERT ON DUPLICATE KEY UPDATE and summary counters.
May 29, 2006 By 48 Comments
… just incremented and last visit timestamp updated. The benefit of using this feature insted of INSERT + UPDATE could be different, depending on number of new rows and data set size. 30% speedup should be typical. Performance increase…
Post: Analyzing air traffic performance with InfoBright and MonetDB
October 2, 2009 By 50 Comments
… have commercial success Worth to note that MonetDB supports all INSERT / UPDATE / DELETE statements (and space is price for that as I… ICE edition allows you only LOAD DATA. InfoBright Enterprise allows INSERT / UPDATE but that also is not for online transactions processing. Compression… if you want to compare or get info about air performance.
