Search Results for: mysql user cpu limit

Top 5 Wishes for MySQL

About a week ago Marten send me email pointing to his article published on Jays Blog (Come on Marten, it is time for you to get your own blog). I should have replied much earlier but only found time to do that now. So here is my list 1. Be Pluggable Unlike many OpenSource projects […]

MySQL Users Conference – Innodb

It might look like it is too late to write about stuff happened at Users Conference but I’m just starting find bits of time from processing accumulated backlog. The Theme of this Users Conference was surely Storage Engines both looking at number of third party storage engine presented, main marketing message – Storage Engine partnership […]

Why MySQL could be slow with large tables ?

If you’ve been reading enough database related forums, mailing lists or blogs you probably heard complains about MySQL being unable to handle more than 1.000.000 (or select any other number) rows by some of the users. On other hand it is well known with customers like Google, Yahoo, LiveJournal,Technocarati MySQL has installations with many billions […]

Update on the InnoDB double-write buffer and EXT4 transactions

In a post, written a few months ago, I found that using EXT4 transactions with the “data=journal” mount option, improves the write performance significantly, by 55%, without putting data at risk. Many people commented on the post mentioning they were not able to reproduce the results and thus, I decided to further investigate in order […]

MongoDB’s flexible schema: How to fix write amplification

Being schemaless is one of the key features of MongoDB. On the bright side this allows developers to easily modify the schema of their collections without waiting for the database to be ready to accept a new schema. However schemaless is not free and one of the drawbacks is write amplification. Let’s focus on that […]

Looking deeper into InnoDB’s problem with many row versions

A few days ago I wrote about MySQL performance implications of InnoDB isolation modes and I touched briefly upon the bizarre performance regression I found with InnoDB handling a large amount of versions for a single row. Today I wanted to look a bit deeper into the problem, which I also filed as a bug. First […]

InnoDB’s multi-versioning handling can be Achilles’ heel

I believe InnoDB storage engine architecture is great for a lot of online workloads, however, there are no silver bullets in technology and all design choices have their trade offs. In this blog post I’m going to talk about one important InnoDB limitation that you should consider. InnoDB is a multiversion concurrency control (MVCC) storage […]

Introduction to the Percona Server Audit Log feature

Percona has developed an Audit Log feature that is now included in Percona Server since the recent 5.5 and 5.6 releases. This implementation is alternative to the MySQL Enterprise Audit Log Plugin: Percona re-implemented the Audit Plugin code as GPL as Oracle’s code was closed source. This post is a quick introduction to this plugin. […]