… of subqueries/multiple joins vs. multiple queries (e.g. …store an interim result set, and then use …MySQL to scan the `title` table first, grouping by kind_id in index order. This made the first table in the EXPLAIN seem like…that sometimes you find unexpected differences in performance like this, …
Post: MySQL and the SSB - Part 2 - MyISAM vs InnoDB low concurrency
May 22, 2013 By Leave a Comment
… In my previous blog post I compared MySQL 5.5.30 to MySQL 5.6.10, both with default settings…12GB of data in the largest table. You can find the individual SSB query definitions in my previous blog …, which is faster using MyISAM than InnoDB. Like the queries in Flight #3 that are faster using MyISAM…
Post: Virident vCache vs. FlashCache: Part 1
May 16, 2013 By 3 Comments
… feature-set comparison between vCache and FlashCache and also to conduct some benchmarks for the use case where the MySQL working set is… of flushing are useful in different situations, and I’d like to see a non-blocking background flush in vCache, but if I… do not. I find the vCache implementation more useful than the one present in FlashCache. Winner: vCache. Although nobody likes a tie, if…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
… – Scale Factor 1 – Mysql 5.5 vs 5.6 response times are in seconds (lower is better…flight” of queries represents a set of drill-down queries to find an anomaly. I am … 1 row in set (12.36 sec) mysql> select * from information_schema.global_status where variable_name like ‘%innodb%read%’; …
Post: Multi Column indexes vs Index Merge
September 19, 2009 By 31 Comments
…MySQL will dive into the index to find first matching row and when will continue scanning index in…4.5% it is most likely better to use single index… 1 row in set (0.00 sec) As you can see in this case MySQL does…
Post: ANALYZE: MyISAM vs Innodb
September 3, 2008 By 9 Comments
…mysql> show variables like “myisam_stats_method”; +———————+—————+ | Variable_name | Value | +———————+—————+ | myisam_stats_method | nulls_unequal | +———————+—————+ 1 row in set…
Post: TPC-H Run on MySQL 5.1 and 6.0
April 10, 2008 By 16 Comments
…you like. It can be downloaded here So let us first take a look at MySQL 5.1.23 vs 6.0.4 results for 10GB data set which “fits in memory”. The cut…MySQL 6.0 optimizer improvements effort. 100GB Results are more interesting because this is database size for which you can find…
Post: COUNT(*) vs COUNT(col)
April 10, 2007 By 45 Comments
… they happen to like, while there is substantial difference in performance and …in set (0.00 sec) mysql> select count(val) from fact; +————+ | count(val) | +————+ | 7216582 | +————+ 1 row in set (1.17 sec) mysql… values in it and so MySQL have to perform table scan to find out…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 141 Comments
… customers like Google, Yahoo, LiveJournal,Technocarati MySQL has …vs range scan by index: mysql> select count(pad) from large; +————+ | count(pad) | +————+ | 31457280 | +————+ 1 row in set (4 min 58.63 sec) mysql… perform complex queries finding relationships between objects. …
Post: MySQL net_write_timeout vs wait_timeout and protocol notes
July 8, 2007 By 1 Comment
… received. Result set however comes back in multiple pieces and if you’re using mysql_use_result …find out client just is just busy and it is not network issue – well this comes from simplicity of MySQL…of. You can’t use something like mysql_ping because connection is in the stage of getting the data…
