Suppose you have turned on innodb_file_per_table (which means that each table has its own tablespace), and you have to drop tables in a background every hour or every day. If its once every day then you can probably schedule the table dropping process to run during off-peak hours. But I have seen cases where the [...]
DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
Optimizing slow web pages with mk-query-digest
April 7, 2011 By 14 Comments
I don’t use many tools in my consulting practice but for the ones I do, I try to know them as best as I can. I’ve been using mk-query-digest for almost as long as it exists but it continues to surprise me in ways I couldn’t imagine it would. This time I’d like to share [...]
Intro to OLAP
July 12, 2010 By 10 Comments
This is the first of a series of posts about business intelligence tools, particularly OLAP (or online analytical processing) tools using MySQL and other free open source software. OLAP tools are a part of the larger topic of business intelligence, a topic that has not had a lot of coverage on MPB. Because of this, [...]
Color code your performance numbers
June 2, 2010 By 4 Comments
When analyzing how good or bad response time is it is not handy to look at the averages, min or max times – something what is easily computed using built in aggregate functions. We most likely would like to see some percentile numbers – 95 percentile or 99 percentile. The problem is computing these in [...]
Maatkit Now Supports Memcached
July 24, 2009 By 11 Comments
Have you ever wondered how optimized your Memcached installation is? There is a common misconception that one doesn’t have to think too deeply about Memcached performance, but that is not true. If your setup is inefficient, you could: Burn Memory Waste Network Round-Trips Store Keys That Never Get Retrieved Have a Low Cache Hit Ratio [...]
SHOW OPEN TABLES – what is in your table cache
December 14, 2008 By 3 Comments
One command, which few people realize exists is SHOW OPEN TABLES – it allows you to examine what tables do you have open right now:
1 2 3 4 5 6 7 | mysql> show open tables from test; +----------+-------+--------+-------------+ | Database | Table | In_use | Name_locked | +----------+-------+--------+-------------+ | test | a | 3 | 0 | +----------+-------+--------+-------------+ 1 row in set (0.00 sec) |
Using GROUP BY WITH ROLLUP for Reporting Performance Optimization
September 17, 2007 By 14 Comments
Quite typical query for reporting applications is to find top X values. If you analyze Web Site logs you would look at most popular web pages or search engine keywords which bring you most of the traffic. If you’re looking at ecommerce reporting you may be interested in best selling product or top sales people. [...]
What would make MySQL Multiple Queries Usable ?
September 5, 2007 By 1 Comment
MySQL Has API to run Multiple Queries at once. This feature was designed mainly with saving network round trip in mind and got a little traction due to associated security risks and not significant gains in most cases. What would make MySQL Multiple Queries API more usable ?
