June 19, 2013

Post: MySQL Query Patterns, Optimized - Webinar questions followup

June 3, 2013 By 2 Comments

… to store an interim result set, and then use that to …syntax to look up values against multiple columns in a compound index, then the…in this case to force MySQL to scan the `title` table first, grouping by kind_id in… is that sometimes you find unexpected differences in performance like this, so …

Filed Under: Insight for Developers, MySQL, MySQL Webinars Tagged With: , , ,

Post: Multicast replication in Percona XtraDB Cluster (PXC) and Galera

June 5, 2013 By

… multiplication and synchronous clusters I’ve seen a lot of people setting up clusters with 3-6+ nodes on 1 … mysql 20u IPv4 39685 0t0 TCP *:3306 (LISTEN) Now, let’s re-do our above test: # 2 nodes in the …_address setting on each node if this IP is not the default IP of the server. I could not find …

Filed Under: Percona Software, Percona XtraDB Cluster Tagged With: , , ,

Post: Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2

May 3, 2011 By 13 Comments

… purge thread and in MySQL 5.6.2 one can have multiple dedicated purge threads. Percona Server 5.1 supports multiple purge threads too… 5.5 yet. Let’s test these two implementations and find out what benefits, if any, do the additional purge threads… tested setting–multiple purge thread implementation at the moment seems to be the one in Percona Server 5.1. MySQL 5.6.2 multiple purge…

Filed Under: MySQL

Post: Quickly finding unused indexes (and estimating their size)

December 5, 2012 By 2 Comments

…in, garbage-out and you risk dropping necessary indexes. To accomplish merging multiple result sets…in set (0.03 sec) Now I need a way to find the set of indexes in all_indexes, but not in…index sizing information in the all_indexes view: mysql> select * from all_indexes\G … …

Filed Under: Insight for DBAs, MySQL, Percona Software

Post: Two Types of MySQL Users

May 10, 2010 By 5 Comments

In comments to my previous post I got number number of comments saying if MySQL would not have multiple…set of features which are enough for majority of users. Note it was note about cool unique features which MySQL…for lower costs. You will find for a lot of users in the Enterprise space this is what…

Filed Under: Insight for Developers, MySQL

Post: InnoDB Full-text Search in MySQL 5.6 (part 1)

February 26, 2013 By 1 Comment

…, it’s entirely possible to DROP multiple FT indexes with InnoDB in the same ALTER TABLE statement, but …in set (0.00 sec) mysql> delete from dir_test_innodb LIMIT 200000; Query OK, 200000 rows affected (8.65 sec) mysql… I_S tables, I do find that the number of rows in I_S.innodb_ft_index_table …

Filed Under: Insight for DBAs, Insight for Developers, MySQL Tagged With: , , , , ,

Post: The Optimization That (Often) Isn't: Index Merge Intersection

December 14, 2012 By 6 Comments

… indexes on them, MySQL could sometimes make use of the multiple indexes. For instance, “…in this merge operation and then perform a set intersection on the results. Here’s one situation where trying to do multiple… should be finding and manipulating data, they can be quite effective. In the case of…

Filed Under: Insight for DBAs, Insight for Developers, MySQL

Post: Shard-Query turbo charges Infobright community edition (ICE)

May 6, 2011 By 23 Comments

…in the data set. mysql> select count(*) from dim_airport; +———-+ | count(*) | +———-+ | 396 | +———-+ 1 row in set… directly, in parallel, to multiple hosts. Shard-Query will execute queries in …publication, as a courtesy. All findings are represented truthfully, transparently, and…

Filed Under: MySQL

Post: Talking MySQL to Sphinx

April 19, 2009 By 4 Comments

… 2735703 | 139448919 | 2735703 | +————+——–+———-+———–+———+ 10 rows in set (32.47 sec) MySQL mysql> select max…in the tested version. Also note the result set difference – Sphinx finds no rows and creates no groups while MySQL… multiple CPU cores and multiple nodes in the…

Filed Under: Insight for Developers Tagged With:

Comment: How to find wrong indexing with glance view

August 23, 2008 By 27 Comments

…multiple columns or intersection of multiple accesses by indexes. When we talk about index_merge_intersection, we should understand that mysql finds one set using an index, another set and then finds records which exist in both sets [2]. Consider this “…

Filed Under: Insight for DBAs Tagged With:
« Older Posts