This blog is about table partitioning in NDB Cluster. We will see how this feature has been enhanced from version to version. Also we will see which partitioning user should use under which scenario. Here I will assume that the user has some knowledge on NDB cluster.

Data distribution and table partitioning are usually coupled together. In NDB, when we talk about table partitioning, we mean ‘data distribution’ mainly as NDB doesn’t fully support RANGE, HASH or LIST partitioning. Most of the enhancements made to partitioning over the years are about ‘data distribution’ rather than supporting various partitioning schemes. The main goals of data distribution are:

- Balance: Avoid premature bottlenecks of memory, storage, cpu or network
- Scaling: Make use of all resources, add capacity with new resources
- Efficiency: Locality of access and minimal unnecessary data transfer

To …

When you work with AWS Aurora you have limited admin privileges. There are some different grants for MySQL including SELECT INTO S3 and LOAD FROM S3 that replace the loss of functionality to SELECT INTO OUTFILE and mysqldump/mysqlimport using a delimited format. While I know and use lambda capabilities, I have never executed anything with INVOKE LAMDBA directly from the database.

This week I found out about INVOKE COMPREHEND (had to look that product up), and …

We are glad to inform our MySQL users, that a new version of our Visual Studio plugin for MySQL database development, dbForge Fusion for MySQL, v.6.6, has been just rolled out. Connectivity The new version features a massive update of connectivity options implemented to ensure that you can easily connect and work with the latest […]

The post New Connectivity Options in dbForge Fusion for MySQL, v6.6 appeared first on Devart Blog.

When you insert data into a database and run COMMIT you expect things to be there: Atomically, Consistent, Isolated and Durable

, like Codd commanded us 40 years ago, but also quickly. There is a surprising amount of sophistication being poured into this, but since I do not want to shame MongoDB and Redis developers in this post, I am not going to talk about that much in this place.

We are instead trying to understand what our databases are doing all day, from the point of view of the storage stack.

That Brendan Gregg Graphics

Here is your performance tooling (sans EBPF) as shown by Brendan Gregg in various iterations. We are interested into the various blues in this graphic, VFS and downwards. The most detailed information of what goes on in the blue stack is given by blktrace. It’s an I/O request recorder.

Unfortunately, blktrace …

MySQL-Shell has had a set of “Util” object functions for almost a year as of this post. It is this added functionality that negates any reason someone would still need to use the old mysqldump client. It (mysqldump) helped the MySQL Community for a long, long time. It also introduced a large amount of garbage and messiness in… Read More »

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 …