I've seen some confusion on what constitutes a keyword or a reserved word in MySQL. The manual defines them, and has a complete list. Reserved words are a special subset of keywords, and you can't use a reserved word as an identifier unless you quote it with backticks. I discourage the use of backticks to quote identifiers, because it allows you to use lots of words and characters in your identifier that you'll probably regret later. For example:

`` mysql> create tableYou will regret this!((╯°□°）╯︵ ┻━┻` int); Query OK, 0 rows affected (0.03 sec)

mysql> desc You will regret this!; +--------------------------------+---------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------------------------------+---------+------+-----+---------+-------+ | …

This post is about setting up Master- Slave replication on MySQL database. Here we assume that, primary master server is up and running and you need to add another server as a slave to an existing server. The following step by step guide will help you to set up the replication.Step 1: Enable binary log on master server:

Binary logs are the source of information for the slave server to replicate the database from master server. The slave server downloads the binary logs and executes it as a SQL statement. In order to enable the binary logs add the following parameters to configuration file and restart the server.[mysqld]log-bin = /path/to/log/mysql-binserver-id = 1expire_logs_days = 15max_binlog_size = 1Gbinlog_format = MIXED

In order to verify whether the binary log enabled or not, just run of the following command.SHOW MASTER STATUS \G
SHOW BINARY LOGS;
SHOW VARIABLES LIKE ‘%log-bin%’;

Step 2: …

Percona is glad to announce the GA release of Percona XtraBackup 2.4.3 on May 23rd, 2016. Downloads are available from our download site and from apt and yum repositories.

Percona XtraBackup enables MySQL backups without blocking user queries, making it ideal for companies with large data sets and mission-critical applications that cannot tolerate long periods of downtime. Offered …

Windows Nano Server is a deployment option of the upcoming Windows Server 2016. It is a “headless” version of Windows Server, pared back to provide the bare essentials necessary to host server / “born in the cloud” applications such as MySQL.…

MySQL Replication can be fragile: whenever it encounters a connectivity error, it will retry and if it is a serious error, it will simply stop. Obviously in the latter case, you will need to repair the broken replication yourself.

The most common problems with replication are when it stops due to either master failure or network problems. In case the master fails, the whole topology becomes read-only and this means the write queries cannot be applied anymore. This is where normally you would promote one of the replicas to become the new master. To illustrate the difference in promotion between GTID and non-GTID cases, we will go through the manual promotion process below.

Most advanced slave without GTID

The first step in this promotion is to find the most advanced slave. As the master is no longer available, not all replicas may have copied and applied the same amount of transactions. So it is key to find the most …

In this blog, I will provide answers to the Q & A for the Troubleshooting Slow Queries webinar.

First, I want to thank you for attending the April 28 webinar. The recording and slides for the webinar are available here. Below is the list of your questions that I wasn’t able to answer during the webinar, with responses:

Q: I’ve heard that is a bad idea to use

select *

; what do you recommend?

A: When I used

SELECT *

 in my slides, I wanted to underline the idea that sometimes you need to select all columns from the …

Percona is glad to announce the new release of Percona XtraDB Cluster 5.6 on May 20, 2016. Binaries are available from the downloads area or our software repositories.

Percona XtraDB Cluster 5.6.29-25.15 is now the current release, based on the following:

• Percona Server 5.6.29-76.2
• …

The majority of DBA’s perform health checks every now and then. Usually, it would happen on a daily or weekly basis. We previously discussed why such checks are important and what they should include.

To make sure your systems are in a good shape, you’d need to go through quite a lot of information - host statistics, MySQL statistics, state of backups, logs and so forth. Such data should be available in every properly monitored environment, although sometimes it is scattered across multiple locations - you may have one tool to monitor MySQL state, another tool to collect system statistics, maybe a set of scripts, e.g., to check the state of your backups. This makes health checks much more time-consuming than they should be - the DBA has to put together the different pieces to understand the state of the system.

Integrated …

This year at Etsy, we spun up a “Database Working Group” that talks about all things data. It’s made up of members from many teams: DBA, core development, development tools and data engineering (Hadoop/Vertica). At our last two meetings, we started talking about how many “sources of information” we have in our environment. I hesitate to call them “sources of truth” because in many cases, we just report information to them, not action data based on them. We spent a session whiteboarding all of of these sources and drawing the relationships between them. It was a bit overwhelming to actually visualize the madness.

A few examples:

• We use Chef for configuration management and Chef knows about all database server. It made sense for us to build out our monitoring to generate Nagios configuration based on that data from Chef. When …

In this blog post, we’ll discuss fixing MySQL scalability problems using either ProxySQL or thread pool.

In the previous post I showed that even MySQL 5.7 in read-write workloads is not able to maintain throughput. Oracle’s recommendation to play black magic with

innodb_thread_concurrency

 and

innodb_spin_wait_delay

 doesn’t always help. We need a different solution to deal with this scaling problem.

All the conditions are the same as in my previous run, but I will use:

• ProxySQL limited to 200 connections to MySQL. ProxySQL has a capability to multiplex incoming connections; with this setting, even with 1000 connections to the proxy it will …