Not translated yet …
A short article today to give you a tips on how to delete table from multiple databases, based on criteria. Sometimes you have to delete lot of tables but you can’t drop the database(s). Here is the method to select all the tables you want to delete and delete them !
Today we’re coming back to MySQL with a post talking about how to calculate percentile value using MySQL. We gonna see two methods that use the same logic but one uses two requests and the other one in only one request.
I want to warn you about performance issues that you could face regarding to the number of rows on which you want to calculate it.
If you don’t really know what is behind the percentile, go first check this link.
If, I as do, you have MyISAM tables (default storage engine until 5.5.5) and you want to switch them to InnoDB, because you plan to update to MySQL >= 5.5.5, you will be able to switch but be careful with indexes !
I guess that, as I do, you appreciate to know MySQL database’ and tables size. It is possible using simple requests based on the database information_schema