This is a Quick Peek at what Oracle delivered with MySQL 8.0.34 and 8.1.0 on July 17th, 2023. MySQL previously released software quarterly as part of a continuous delivery system where new features were made available. Many people loved access to the new features even if they could be risky, but others wanted stability and bug fixes only. Now there is a long-term support (LTS) version for the more conservative and the risk-averse folk that will have a roughly two-year lifespan between major releases.

The release with the new features will be called the Innovation series, and MySQL 8.1.0 is the first of these releases. And the LTS will be based on 8.0.34. Please note that comments in italics are mine and do not reflect the views of Percona and possibly not anyone else.

Quick reminder

The End of Life for MySQL 8.0 is in April of 2026, and the …

In this blog post, we will describe the improvements to Percona XtraBackup 8.0.33-28 (PXB), which significantly reduces the time to prepare the backups before the restore operation. This improvement in Percona XtraBackup significantly reduces the time required for a new node to join the Percona XtraDB Cluster (PXC).

Percona XtraDB Cluster uses Percona XtraBackup to do SST (State Snapshot Transfer) from one node to another. When a new node joins the cluster, SST is performed to receive the data from DONOR to the JOINER. JOINER uses PXB to stream the data directory from DONOR. JOINER must prepare the backup before using it. It is observed that when the DONOR has a huge number of tablespaces (one million),  XtraBackup on JOINER …

When it comes to backups, there are several options for saving backup files. You can choose to save them locally on the same server, stream them to different servers, or store them in object storage. Percona XtraBackup facilitates streaming through the use of an auxiliary tool called xbcloud.

STDOUT Datasink

This diagram displays the process of streaming a backup to object storage utilizing the current STDOUT datasink:

• XtraBackup spawns multiple copy threads. Each one will be reading a chunk of data from a specific file.
• Each copy thread will write the chunk of data to a pipe (aka STDOUT).
• Xbcloud will have a red thread that will be responsible for reading each chunk of data from STDIN. This chunk will be uploaded to object storage utilizing an async request, and a callback will be added to an …

Well, “easy” if you know just a tiny bit of C++.

MySQL is well known for its ease of use, being easy to install, easy to configure, and easy to maintain. What if there is something more that you’d like MySQL to do? How would you integrate some new fancy processing library into MySQL without having to recreate the complexities in pure SQL?

MySQL Loadable Functions would be the way to go. In this blog post, you’ll learn how to set up a build environment for compiling your own MySQL plugin to be loaded into MySQL as a function. Our function will implement a ULID generator using a C++ library from ChrisBove/ulid.

Creating the build environment

The first step is downloading the …

This blog was originally published in January 2022 and was updated in July 2023.

Working with hundreds of different customers, I often face similar problems around running queries. One very common problem when trying to optimize a database environment is index usage. A query that cannot use an index is usually a long-running one, consuming more memory or triggering more disk iops.

A very common case is when a query uses a filter condition against a column that is involved in some kind of functional expression. An index on that column can not be used.

Starting from MySQL 8.0.13, functional indexes are supported. In this article, I will first explain an overview of indexes in MySQL and cover the MySQL CREATE INDEX before diving into showing what functional indexes are and how they work.

Introduction to MySQL Indexes

In the world of modern web applications, it is increasingly important to support a diverse range of languages and character sets. With the rise of globalization, the need to store and process multilingual data has become essential. MySQL, one of the most popular relational database management systems, recognizes this need and has introduced utf8mb4 in its 8.0 version as a game-changer. In this blog post, we will explore utf8mb4 and its advantages in MySQL 8.0, backed by practical examples.

Understanding utf8mb4

Before diving into the benefits, let’s clarify what utf8mb4 represents. In MySQL, “utf8” refers to a character encoding that supports the Unicode character set using a maximum of three bytes per character. However, the original utf8 implementation in MySQL does not cover all Unicode characters. utf8mb4, on the other hand, is a modified version of utf8 that supports the complete Unicode character set, including emojis …

Fragmentation is a common concern in some database systems. Highly fragmented tables can affect performance and resource allocation. But reducing fragmentation often involves rebuilding the table completely. This blog post will discuss fragmentation and its impact on InnoDB.

What is fragmentation?

We say that something is fragmented when it is formed by parts that are separate or placed in a different order than the natural one. In databases, we can experiment with different types of fragmentation:

• Segment Fragmentation: segments are fragmented; they are stored not following the order of data, or there are empty pages gaps between the data pages.
• Tablespace Fragmentation: the tablespace is stored in non-consecutive filesystem blocks.
• Table Fragmentation: data is stored not following the primary key order (heap tables), …

Upgrading to MySQL version 8.0 is a hot topic since version 5.7 is approaching the official end of life very soon. MySQL 5.7 EOL is set for the end of October 2023.

If you feel unprepared for the upgrade, consider post-EOL support from Percona. But it would be the worst if you proceeded with the upgrade in haste.

• Long database service downtime
• Some queries become slow
• Applications stop working due to incompatibilities
• Data loss

This is what can happen if MySQL’s major upgrade to 8.0 turns out not as you hoped for. Yes, it can be that serious, so do consider the major upgrade as an important project, not just a routine maintenance task! From my experience as a Support Engineer, I think the most frequent problem is query …

Recently, I was working on a very unfortunate case that revolved around diverging clusters, data loss, missing important log errors, and forcing commands on Percona XtraDB Cluster (PXC). Even though PXC tries its best to explain what happens in the error log, I can vouch that it can be missed or overlooked when you do not know what to expect.

This blog post is a warning tale, an invitation to try yourself and break stuff (not in production, right?).

TLDR:
Do you know right away what happened when seeing this log?

2023-06-22T08:23:29.003334Z 0 [ERROR] [MY-000000] [Galera] gcs/src/gcs_group.cpp:group_post_state_exchange():433: Reversing history: 171 -> 44, this member has applied 127 more events than the primary component.Data loss is possible. Must abort.

Demonstration

Using the …

MySQL Shell is an advanced client and code editor for MySQL. In addition to the provided SQL functionality, similar to MySQL, MySQL Shell provides scripting capabilities for JavaScript and Python and includes APIs for working with MySQL. The X DevAPI enables you to work with both relational and document data, and MySQL Shell 8.0 is highly recommended for use with MySQL Server 8.0 and 5.7.

MySQL Shell includes utilities for working with MySQL. To access the utilities from within MySQL Shell, use the util global object, which is available in JavaScript and Python modes, but not SQL mode. These are the utilities to take a backup; let’s see some basic commands.

• util.dumpTables – Dump one or more tables from single database
• util.dumpSchemas – Dump one or more databases
• util.dumpInstance – Dump full instance
• util.loadDump – Restore dump

1. Single table …