…. There are two reasons for that. First, MySQL/InnoDB uses async writes, so this will emulate database load… every 10 sec to see how stable the performance is, and it really helps to observe some artifacts… not attend my talk – you are welcome to join the webinar. Follow @VadimTk !function(d,s,id){…
Post: Testing STEC SSD MACH16 200GB SLC
April 25, 2012 By 7 Comments
…. There are two reasons for that. First, MySQL/InnoDB uses async writes, so this will emulate database load… every 10 sec to see how stable the performance is, and it really helps to observe some artifacts… not attend my talk – you are welcome to join the webinar. Disclaimer: This benchmark is done as…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
… values by PK column and then performing the lookup, and then there are other possibilities like InnoDB doing read_ahead by noticing… is further extended to improve join performance. As I told you above, when table t1 would be joined to table t2, then selected… 2.2G Innodb_data_reads 329115 355323 143808 335526 16164 15506 Innodb_pages_read 329115 355323 143808 358308 144798 144881 Innodb_rows_read…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
… these lookups are performed in a single call to the storage engine and the counters Handler_read_key and Innodb_rows_read… and then to perform the MRR range scan on the PK. This causes the counters Handler_read_key and Innodb_rows_read… improve the performance of secondary key lookups as well. But this works only with joins and specifically with Block Access Join Algorithms. So…
Post: MariaDB 5.3 is released as GA!
March 5, 2012 By 17 Comments
… through speedier joins, faster subqueries, and elimination of useless tables in joins Thread pooling … to partitioning, and the addition of multiple InnoDB buffer pools. Best of all, MariaDB …, with different characteristics, and feature and performance improvements are moving rapidly forward for …
Post: Enum Fields VS Varchar VS Int + Joined table: What is Faster?
January 24, 2008 By 27 Comments
… often would be larger. It is also interesting to note performance of Innodb tables in this case: for VARCHAR it takes about… show close performance, while join performance degraded dramatically. Here is why: mysql> explain select SQL_NO_CACHE c.city from cities_join c JOIN states…, but join query performance is 30% lower. Also note the times themselves – traversing about same amount of rows full table scan performs about…
Post: Join performance of MyISAM and Innodb
May 29, 2006 By 6 Comments
… the following: Innodb primary key joins are very fast as data is clustered together with index and generally highly optimized Innodb builds hash… faster MyISAM does compression for character keys which makes it perform slower for random lookups MyISAM generally has lower processing overhead…
Post: JOIN Performance & Charsets
October 21, 2008 By 2 Comments
… used on joined columns can have a significant impact on the performance of your queries. Take the following example, using the InnoDB storage…, `v` varchar(128) NOT NULL, PRIMARY KEY (`char_id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; CREATE TABLE `t2` ( `id` int unsigned NOT…, from 4.33 to 3.12 seconds. This test was performed with MySQL 5.0.67, FreeBSD 7, on a box…
Post: INSERT INTO ... SELECT Performance with Innodb tables.
July 12, 2006 By 21 Comments
Everyone using Innodb tables probably got use to the fact Innodb tables perform non locking reads, meaning unless you use some modifiers such… tables with where clause and joins. It is important for tables which is being read to be Innodb – even if writes are done in MyISAM table. So why was this done, being pretty bad for MySQL Performance and…
Post: Using CHAR keys for joins, how much is the overhead ?
June 18, 2007 By 18 Comments
… integer based join. So how do I read these results ? CHAR keys are indeed slower for joins compared to integer keys Performance degradation can range from few percent to couple of times for Innodb tables MyISAM…
