'Tunning' Tag

• It’s about Time.

  January 27, 2011

  WHAT TIME IS IT? This post started with a simple question: “Does the function NOW() get executed every time a row is examined?” According to the manual,  “Functions that return the current date or time each are evaluated only once per query …. multiple references to a function such as NOW() … produce the same [...]

  posted in Commentary, Tips & Tricks, Tunning by mark

• Does Size or Type Matter?

  July 27, 2010

  MySQL seems to be happy to convert types for you. Developers are rushed to complete their project and if the function works they just move on. But what is the costs of mixing your types? Does it matter if your are running across a million rows or more? Lets find out. Here is what the [...]

  posted in Tips & Tricks, Tunning by mark

• MySQL Network Connections

  May 7, 2010

  If your MySQL server has hundreds of clients (applications) and tens of thousands of queries per second,  MySQL default network settings may NOT be for you.  Network performance is not often a significant factor in the performance of MySQL.  That said, there are things to consider. If you are building new applications make these changes [...]

  posted in Tunning by mark

• MySQL master/slave support merged into Linux-HA

  April 21, 2010

  (Re-posted from Florian’s blog.) MySQL replication support for the Pacemaker cluster manager (the stuff that we explained in this webinar) has made it into the Linux-HA resource agents default branch. If you are interested in testing — and you should! — please read the extended announcement. Feedback is extremely welcome on the linux-ha-dev mailing list. [...]

  posted in Commentary by mark

• Single Query Profiling

  February 26, 2010

  Every wounder what was taking MySQL so long to run your query.  You can ask it. mysql > set profiling=1; mysql> SELECT * FROM country WHERE city like ‘okla’  order by name; mysql> SHOW PROFILES; You should now see a table with a single row, with the number 1 to the left of your query. [...]

  posted in Commentary by mark

• MySQL Table Caching

  February 25, 2010

  Too much of a good thing… I have had a lot of people asking me about MySQL lately so I thought is was time to share something I learned.  Too much caching space in MySQL can be a bad thing. You would thing the more you can stuff your entire database into memory the better [...]

  posted in Commentary by mark