…Query over Hive is that it works with existing MySQL data sets and queries. Another advantage is that it works with all MySQL…query: BETWEEN or IN clauses, subqueries in the FROM clause, UNION or UNION ALL…LIMIT 10; The next queries show how performance is improved when Shard-Query…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
…all the data points you need to attack the right query in the right way. But vanilla MySQL does have its limitations… 1.00 0.00 SELECT UNION wp_pp_daily_summary wp…(105/70%), wp_blog_two (34/22%)… 1 more # Query_time distribution # 1us # 10us # 100us ################### # 1ms …
Post: ORDER BY ... LIMIT Performance Optimization
September 1, 2006 By 93 Comments
… a bit ugly) will be UNION workaround I already wrote about… limit 10; There could be many possible limiting factors with all of… a,b limit 10 – In this case first two columns …query log as query which does not use indexes, even if it is quite fast: mysql> explain select * from test order by k limit…
Comment: How to find wrong indexing with glance view
August 23, 2008 By 27 Comments
…, looking_for, location; integer – age 3) All queries fall into X IN (…) AND Y…623, 18th – 3000 (looks like it’s limit and most probably it’… Gender, Age, Available). So mysql can choose between two which is more selective…union-to-implement-loose-index-scan-to-mysql/#comment-1695 2. http://dev.mysql…
