…performance, and should be avoided. By the way, a good practice to avoid this is always naming your keys…
Post: MySQL and the SSB - Part 2 - MyISAM vs InnoDB low concurrency
May 22, 2013 By Leave a Comment
… adaptive hash index is improving performance of InnoDB significantly during the hot run, as hash indexes are faster than a b-tree index. Also… index creation (merge sort). For the MyISAM tests I used a 10GB key buffer. I used ALTER TABLE DISABLE KEYS and built the keys with sort via ALTER TABLE ENABLE KEYS. my.cnf…
Post: MySQL Query Patterns, Optimized - Webinar questions followup
June 3, 2013 By 2 Comments
…a suboptimal form. Q: Doesn’t the primary key solution for random selection only work when …randomly choosing rows involves some compromise, either of performance, or of accuracy of randomness. The ORDER BY …each correlation name (k1, k2, k3) is an index lookup. Look at the EXPLAIN output — it …
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
… Server with TokuDB, of course I wanted to compare InnoDB performance vs TokuDB. I have a particular workload I’m interested… ” NOT NULL, pad CHAR(60) DEFAULT ” NOT NULL, PRIMARY KEY (id) ) CREATE INDEX k on sbtest$I(k) and tables sbtest$I… how both InnoDB and TokuDB performs if PK is (`id`,`hid`,`mid`). This also will affect select performance, so we will need…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
…the first post: single SELECT queries doing PRIMARY KEY lookups (aka QPS sysbench mode); same MySQL …table_open_cache=5000 query_cache_type=OFF performance_schema=0 warmup To warmup server and load…nontrx –oltp-read-only=off –oltp-index-updates=0 –oltp-non-index-updates=0 run POINT_SELECT + UPDATE…
Post: Percona Server 5.5.30-30.2 rerelease fixes non-restart issue
April 24, 2013 By Leave a Comment
…Server for MySQL has fixed a number of performance bugs. (Alexey Kopytov) Drop table performance feature has been removed and its …implicit secondary index with the same name. Fixed by detecting such cases and omitting the corresponding secondary keys from deferred key creation optimization…
Post: Percona Server for MySQL 5.5.30-30.2 now available
April 10, 2013 By 10 Comments
…Server for MySQL has fixed a number of performance bugs. (Alexey Kopytov) Drop table performance feature has been removed and its …implicit secondary index with the same name. Fixed by detecting such cases and omitting the corresponding secondary keys from deferred key creation optimization…
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
… other magic that helps single node writing in PXC to perform better. gcs.fc_factor If fc_limit controls when flow… large receive queue might be the result of some brief performance issue on a given node, or perhaps the effect of… unique key lookups into the certification index, which is a hash table. A small fc_limit does however keep the certification index smaller…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
… locking in Innodb is a single row (well, the PRIMARY KEY index entry for that row). This means typically on a single… does NOT set an lower bound on performance, only a upper bound. The best performance you can expect is modifying a given… update much faster. I see this tuning very frequently for “performance” reasons when data durability isn’t as crucial. This is…
Comment: MySQL Partitioning - can save you or kill you
April 30, 2013 By 45 Comments
…leads to scanning the entire last two partitions, performance is not bad. (The last 2-3 …a single row based on a UNIQUE/PRIMARY key and it can prune, the delete involves (1… ‘range’ delete would mostly follow above two points. * Secondary indexes are also BTrees, so they need updating (although…
