April 24, 2014

Quickly finding unused indexes (and estimating their size)

I had a customer recently who needed to reduce their database size on disk quickly without a lot of messy schema redesign and application recoding.  They didn’t want to drop any actual data, and their index usage was fairly high, so we decided to look for unused indexes that could be removed. Collecting data It’s […]

Find unused indexes

I wrote one week ago about how to find duplicate indexes. This time we’ll learn how to find unused indexes to continue improving our schema and the overall performance. There are different possibilites and we’ll explore the two most common here. User Statistics from Percona Server and pt-index-usage. User Statistics User Statistics is an improvement […]

Query Response time histogram – new feature in Percona Server

Recently we had couple posts dedicated to performance monitoring, i.e. Color code your performance numbers, Performance Optimization and Six Sigma, so you may understand we consider stability of performance numbers as one of important area for database management. That’s why we decided to add histogram of queries response times into Percona Server, and our software […]

SHOW OPEN TABLES – what is in your table cache

One command, which few people realize exists is SHOW OPEN TABLES – it allows you to examine what tables do you have open right now: