Search Results for: single query update

Easy query metrics with MySQL Performance Schema

The MySQL Performance Schema exposes so much data that it’s not trivial to learn, configure, and use. With recently released Percona Agent 1.0.11 you can get query metrics – like min, max, and average query execution time – with a few clicks: Click “Apply” and about two minutes later you’ll have query metrics from Performance Schema, collected and […]

Distributed Set Processing with Shard-Query

Can Shard-Query scale to 20 nodes? Peter asked this question in comments to to my previous Shard-Query benchmark. Actually he asked if it could scale to 50, but testing 20 was all I could due to to EC2 and time limits. I think the results at 20 nodes are very useful to understand the performance: […]

Unused indexes by single query

Usually unused indexes are devil, they waste diskspace, cache, they make INSERT / DELETE / UPDATE operations slower and what makes them worse – it is hard to find them. But now ( with userstatsV2.patch) you can find all unused indexes (since last restart of mysqld) by single query

As you see query […]

Percona Server 5.6.24-72.2 is now available

Percona is glad to announce the release of Percona Server 5.6.24-72.2 on May 8, 2015. Download the latest version from the Percona web site or from the Percona Software Repositories. Based on MySQL 5.6.24, including all the bug fixes in it, Percona Server 5.6.24-72.2 is the current GA release in the Percona Server 5.6 series. Percona Server is open-source […]

Optimizer hints in MySQL 5.7.7 – The missed manual

In version MySQL 5.7.7 Oracle presented a new promising feature: optimizer hints. However it did not publish any documentation about the hints. The only note which I found in the user manual about the hints is: It is now possible to provide hints to the optimizer by including /*+ … */ comments following the SELECT, […]

Choosing a good sharding key in MongoDB (and MySQL)

MongoDB 3.0 was recently released. Instead of focusing on what’s new – that is so easy to find, let’s rather talk about something that has not changed a lot since the early MongoDB days. This topic is sharding and most specifically: how to choose a good sharding key. Note that most of the discussion will also […]