In this blog post we are going to take a closer look at ProxySQL rules. How do they work, and how big is the performance impact of having many rules?

I would like to say thank you to Renè, who was willing to answer all my questions during my tests.

Overview

ProxySQL is heavily based on the query rules. We can set up ProxySQL without rules based only on the host groups, but if we want read/write splitting or sharding (or anything else) we need rules.

ProxySQL knows the SQL protocol and language, so we can easily create rules based on username, schema name and even on the query itself. We can write regular expressions that match the query digest. Let me show you an example:

insert into mysql_query_rules …

If you met one of the (few) MySQL consultants around the globe and asked him/her to review your queries and/or schemas, I am sure that he/she would tell you something regarding the importance of good primary key(s) design. Especially in the case of InnoDB, I’m sure they started to explain to you about index merges and page splits. These two notions are closely related to performance, and you should take this relationship into consideration when designing any index (not just PKs).

That may sound like mumbo jumbo to you, and you may be right. This is not easy stuff, especially when talking about internals. This is not something you deal with on a regular basis, and often you don’t want to deal with it at all.

But sometimes it’s a necessity. If so, this article is for you.

In this article, I want to shed some light in explaining some of the most unclear, behind the scenes operations in InnoDB: page index creation, …

If you met one of the (few) MySQL consultants around the globe and asked him/her to review your queries and/or schemas, I am sure that he/she would tell you something regarding the importance of good primary key(s) design. Especially in the case of InnoDB, I’m sure they started to explain to you about index merges and page splits. These two notions are closely related to performance, and you should take this relationship into consideration when designing any index (not just PKs).

That may sound like mumbo jumbo to you, and you may be right. This is not easy stuff, especially when talking about internals. This is not something you deal with on a regular basis, and often you don’t want to deal with it at all.

But sometimes it’s a necessity. If so, this article is for you.

In this article, I want to shed some light in explaining some of the most unclear, behind the scenes operations in InnoDB: page index …

In MySQL 5.7, one of the most popular new features is the introduction of JSON:

1. The JSON data type
2. A set of 20 functions to search, manipulate and create JSON documents
3. Virtual Columns for JSON indexing

In MySQL 8.0 we plan to extend this functionality (for example: with the addition of JSON aggregate functions), but we are also considering changing the behaviour of one of the existing functions.…

In this blog, we’ll look at how queries in systems with parallel processing can return rows in a non-deterministic order (and how to fix it).

Short story:

Do not rely on the order of your rows if your query does not use

ORDER BY

. Even with

ORDER BY

, rows with the same values can be sorted differently. To fix this issue, always add

ORDER BY ... ID

 when you have

LIMIT N

.

Long story:

While playing with MariaDB ColumnStore and Yandex ClickHouse, I came across a very simple case. In MariaDB ColumnStore and …

Amazon Relational Database Service (RDS) is a hosted database service in the AWS cloud. If your organization’s data is stored in one of the popular database systems, but on a company server or perhaps you’re renting a dedicated server, you might want to consider switching to Amazon RDS.  With Amazon RDS, you can choose from several relational database systems:  MySQL, MariaDB, Oracle, Postgres, and SQL Server, as well as Amazon Aurora.

There are many advantages to Amazon RDS, such as server scaling and load balancing of user traffic. Best of all, it can reduce the operational costs of running database software like MySQL. With Amazon RDS, you don’t need to worry about performing security updates, patching the operating system, or tuning the database. In fact, some of the patches Amazon deploys for MySQL and MariaDB are specifically designed to get better performance in a cloud setting.  Let’s look at some major …

Welcome to another post in the series of Percona Live featured session blogs! In these blogs, we’ll highlight some of the session speakers that will be at this year’s Percona Live conference. We’ll also discuss how these sessions can help you improve your database environment. Make sure to read to the end to get a special Percona Live 2017 registration bonus!

In this Percona Live featured session, we’ll meet Ilya Kosmodemiansky, CEO and Consultant of Data Egret. His session is Linux IO Internals for Database Administrators. Input/output performance problems are an …

In this blog, we’ll look at how to resolve MySQL error code 1215: “Cannot add foreign key constraint”.

Our Support customers often come to us with things like “My database deployment fails with error 1215”, “Am trying to create a foreign key and can’t get it working” or “Why am I unable to create a constraint?” To be honest, the error message doesn’t help much. You just get the following line:

ERROR 1215 (HY000): Cannot add foreign key constraint

But MySQL never tells you exactly WHY it failed. There’s actually a multitude of reasons this can happen. This blog post is a compendium of the most common reasons why you can get ERROR 1215, how to diagnose your case to find which one is affecting you and potential solutions for adding the foreign key.

Overview

In this post I will explain how to transfer a partitioned table using transportable tablespaces on MySQL 5.6. Note that the operation is not officially supported until MySQL 5.7, as the discard tablespace operation will fail if it is run against a partitioned table on MySQL 5.6.

The workaround is transferring each individual partition as if it was a standalone table. Continue reading to learn more about the detailed procedure.

Steps

1. Create the same table structure on the destination server:

[root@mysqlsandbox ~]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.35-80.0 Percona Server (GPL), Release 80.0, Revision f113994f31

Copyright (c) 2009-2016 Percona LLC and/or its affiliates
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. …

The MariaDB project is pleased to announce the immediate availability of MariaDB 10.2.5 Release Candidate (RC). See the release notes and changelog for details. Download MariaDB 10.2.5 Release Notes Changelog What is MariaDB 10.2? MariaDB APT and YUM Repository Configuration Generator Thanks, and enjoy MariaDB!

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