MySQL Shell is the advanced MySQL client, which has many excellent features. In this blog, I am going to explain the MySQL shell commands “\show” and “\watch”. Both commands are very useful to monitor the MySQL process. It provides more insights into the foreground and background threads as well. 

Overview

“\show” and “\watch” are the MySQL shell commands, which can be executed using the Javascript (JS), Python (Py), and SQL interfaces. Both commands are providing the same information, but the difference is you can refresh the results when using the command “\watch”. The refresh interval is two seconds. 

• \show: Run the specified report using the provided options and arguments.
• \watch: Run the specified report using the provided options and arguments, and refresh the results at regular intervals.

Below are the available options you can use with the “\show” …

Introduction In this article, I’m going to explain how to do query profiling using the MySQL Performance Schema. The Performance Schema has been available since MySQL 5.5.3 and allows MySQL to instrument SQL queries and store their trace information in various tables that you can later inspect in order to determine why a given SQL statement is slow. On older versions of MySQL, you might have used the SHOW PROFILE command, but since this feature has been deprecated, you should now use the Performance Schema for SQL query profiling. Enabling the MySQL... Read More

The post MySQL Query Profiling Using Performance Schema appeared first on Vlad Mihalcea.

The Problem

HELP, HELP! My Percona XtraDB Cluster version: 5.7.31-31. Single Node is stuck in a joined state.

I recently had the privilege to help a client with a fascinating issue.

NODE-B dropped out of the 3 node PXC cluster. It looked to be DISK IO that caused NODE-B to fall far behind and eventually be removed from the cluster. A restart of NODE-B allowed it
to rejoin the cluster. NODE-B looked to have been down for about 4 hours. Once NODE-B was back as part of the cluster, it required a full SST.

When NODE-B stayed in a joint state for more than 12 hours, the client gave me a call. They were concerned that there was another issue with this cluster.

Before going forward, let’s make sure we know the CPU, RAM and Database Size.

8 CPU
32 GB RAM
Database Size approx. 2.75TB

Let’s gather some base information.

I pulled the below data once I …

Point-In-Time Recovery (PITR) for MySQL databases is an important feature that is essential and covers common use cases, like a recovery to the latest possible transaction or roll-back the database to a specific date before some bad query was executed. Percona Kubernetes Operator for Percona XtraDB Cluster (PXC) added support for PITR in version 1.7, and in this blog post we are going to look into the technical details and decisions we made to implement this feature.

Architecture Decisions Store Binary Logs on Object Storage

MySQL uses …

If you are dealing with data, and you most probably are if you are reading this, one of your biggest fears would be not to be able to retrieve them. In a world where data actually surround us, it is critical to be able to retrieve them fast and with the best consistency.

Thus, it is always a good idea to have high availability settings in place to avoid loosing your data.

However, most of the times, we may wish or we may need to save the database and our data, and be a DBA-hero. Not an easy task, and it may be smoother to just perform a backup-restore. Sadly, this is not always the case.

So, this is what we will be facing in this article, we are going to see what to do when there is a data corruption in MySQL and the steps we need to perform to try saving our database.

The post MySQL Recovery first appeared on …

I learned this week that 30+ years of Relational Database Management System (RDBMS) experience still does not prepare yourself for the disappointment of working with organizations that use a RDBMS; MySQL specifically; have a released production product, have dozens to hundreds of developers, team leaders and architects, but do not know the importance of, nor use transactions. If I was to ask this when interviewing somebody that would work with a database and the response was it is not important, or not used these days it would be a hard fail.

To use a RDBMS is to understand a very simple principle, a foundation of a transactional system. It is called ACID. Atomicity, Consistency, Isolation, Durability.

In a …

Vitess introduces a new way to run schema migrations: non-blocking, asynchronous, scheduled online DDL. With online DDL Vitess simplifies the schema migration process by taking ownership of the operational overhead, and providing the user a simple, familiar interface: the standard ALTER TABLE statement. Let’s first give some background and explain why schema migrations are such an issue in the databases world, and then dive into implementation details The relational model and the operational overhead # The relational model is one of the longest surviving models in the software world, introduced decades ago and widely used until today.

I’ve already provided some solutions to connect to your MDS instance, using MySQL Router, SSH tunnel, … but one of the best way if you have multiple instance to manage, is to use a VPN.

This post summarize the steps on how to deploy Open VPN and configure your VCN to use it.

So, in OCI, we have already some MDS & Compute instances deployed, this is how the dashboard looks like:

OpenVPN Deployment

We can start by deploying our OpenVPN instance using OCI’s Marketplace:

And you follow the wizard by adding your administrator username and password:

An important step is to use the existing VCN and place the OpenVPN in the public subnet:

And you create the instance:

…

Most developers use some form of auto-incrementing integer counter for a given database table, ensuring uniqueness among the rows. Several of the popular SQL dialects implement this facility. For instance, MySQL’s AUTO_INCREMENT attribute is used to provide a unique identity for a table row. What exactly is the behavior of AUTO_INCREMENT? Can you explicitly use a value of your choosing for it if you need to? How does it count? Continue reading and know the answers to these questions and more…

Image by Gerd Altmann from …

MySQL 5.6.51 is the last release of the MySQL 5.6 series. Oracle will no longer provide updates or security fixes for this version.

Following Percona’s Release Lifecycle policies, the Percona Server for MySQL 5.6 series has reached End of Life (EOL) as well, and we will no longer provide public builds for bugs and security fixes.

We recommend that you upgrade to MySQL 5.7 or Percona Server for MySQL 5.7, or for the latest features, MySQL 8.0 or Percona Server for MySQL 8.0.

Suppose you have not upgraded because you have off-the-shelf applications that also must be upgraded and require 5.6, or you have other …