Planet MySQL Planet MySQL: Meta Deutsch Español Français Italiano 日本語 Русский Português 中文
Showing entries 1 to 1

Displaying posts with tag: tcpdump (reset)

How to find un-indexed queries in MySQL, without using the log
+4 Vote Up -0Vote Down

You probably know that it’s possible to set configuration variables to log queries that don’t use indexes to the slow query log in MySQL. This is a good way to find tables that might need indexes.

But what if the slow query log isn’t enabled and you are using (or consulting on) MySQL 5.0 or earlier, where it can’t be enabled on the fly unless you’re using a patched server such as Percona’s enhanced builds? You can still capture these queries.

The key is knowing what it really means for a query to “not use an index.” There are two conditions that trigger this — not using an index at all, or not using a “good” index.

  [Read more...]
Showing entries 1 to 1

Planet MySQL © 1995, 2014, Oracle Corporation and/or its affiliates   Legal Policies | Your Privacy Rights | Terms of Use

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.