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A graph a day, keeps the doctor away ! – MySQL History List Length

This is the second article of the series dedicated to MySQL trending.

As I wrote before, understanding your workload and seeing the evolution of it over time can help anticipating problems and work on solutions before the breakdown.

This article covers MySQL History List Length also known as HLL.

MySQL History List is related to InnoDB Undo Logs. InnoDB is a multi-version storage engine (MVCC). It keeps information about old versions of changed rows to support transactional features such as concurrency and rollback. This information is stored in undo tablespaces in a data structure called a rollback segment.

This means that you can start a transaction and continue to see a consistent snapshot even if the data changed by other transaction. This behavior is related to the …

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Is MySQL Statement-Based / Mixed Replication Really Safe?

The binary logging format in MySQL has been ROW by default since MySQL 5.7, yet there are still many users sticking with STATEMENT or MIXED formats for various reasons. In some cases, there is just simple hesitation from changing something that has worked for years on legacy applications. But in others, there may be serious blockers, most typically missing primary keys in badly designed schemas, which would lead to serious performance issues on the replicas.

As a Support Engineer, I can still see quite a few customers using STATEMENT or MIXED formats, even if they are already on MySQL 8.0. In many cases this is OK, but recently I had to deal with a pretty nasty case, where not using ROW format was found to cause the replicas to silently lose data updates, without raising any replication errors! Was it some really …

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Galera Cluster for MySQL 8.0.28 and 5.7.37 released

Codership is pleased to announce a new Generally Available (GA) release of the multi-master Galera Cluster for MySQL 5.7 and 8.0, consisting of MySQL-wsrep 5.7.37 (release notes, download) and MySQL-wsrep 8.0.28 (release notes, download) with Galera replication library 3.37 (release notes, download) implementing wsrep API …

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Introduction to ADO.NET

ADO.NET is a part of .NET Framework that provides access to different types of data sources. ADO.NET supports relational, XML and application data. ADO.NET resides in a layer between data sources and client applications and enables customers to retrieve, manipulate and update data through ADO.NET object model. ADO.NET architecture ADO.NET was introduced in the 10th […]

The post Introduction to ADO.NET appeared first on Devart Blog.

Spring Cleaning: Discontinuing RHEL 6/CentOS 6 (glibc 2.12) and 32-bit Binary Builds of Percona Software

As you are probably aware, Red Hat Enterprise Linux 6 (RHEL 6 or EL 6 in short) officially reached “End of Life” (EOL) on 2020-11-30 and is now in the so-called Extended Life Phase, which basically means that Red Hat will no longer provide bug fixes or security fixes.

Even though EL 6 and its compatible derivatives like CentOS 6 had reached EOL some time ago already, we continued providing binary builds for selected MySQL-related products for this platform.

However, this became increasingly difficult, as the MySQL code base continued to evolve and now depends on tools and functionality that are no longer provided by the operating system out of the box. This meant we already had to perform several modifications in order to prepare binary builds for this platform, e.g. installing custom compiler versions or newer versions of various system …

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MySQL 8.0.29: thank you for the contributions

When it’s time for a new MySQL release, it’s also time to thank our contributors !

Released on April 26th, MySQL 8.0.29 contains several contributions from our awesome Community and on behalf of the entire MySQL Team, I would like to thank you all !

This new releases contains patches from Vilnis Termanis, Luke Weber, Meik Milevczik, Song Zhibai, Zheng Lai, Øystein Grøvlen, Facebook, Biran Yue, Hope Lee, Rahul Malik, Christopher Chavez, Chen Yi, Ning PeiPei, Jianjian Song, Jack Wotherspon and Bin Wang.

Once again, thank you all for your great contributions and to the company you are working for.

Here is the list of the above contributions and related bugs:

Clients / Connectors

  • #81519 Connector/Python: Guarantee file closing of input files in optionfiles module – Vilnis Termanis
  • …
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A Quick Peek At MySQL 8.0.29

Oracle released MySQL Server 8.0.29 on April 26th and this is a quick review of the release notes.  I have put my own comments in italics.

So what is in the ’29 release of MySQL Server?  Does it come festooned with new, neat features or is it a big bug-fix bonanza?

The TL;DR

While this server release has some interesting stuff, there is no compelling feature that will necessitate an immediate upgrade.  Read through the release notes to see if anything in there that is a must for you but for most of us, MySQL 8.0.29 does not require an immediate update.  If this was a birthday or holiday present, ’29 is the equivalent of getting a fresh box of dental floss – useful but not thrilling.

The shell is evolving too and the new version for VS Code looks promising.

MySQL Server 8.0.29 UTF8MB3?

The server now makes extensive use of UTF8MB3 (yes 3, not …

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Zero Impact on Index Creation with Amazon Aurora 3

In the last quarter of 2021, AWS released Aurora version 3. This new version aligns Aurora with the latest MySQL 8 version, porting many of the advantages MySQL 8 has over previous versions.

While this brings a lot of new interesting features for Aurora, what we are going to cover here is to see how DDLs behave when using the ONLINE option. With a quick comparison with what happens in MySQL 8 standard and with Group Replication.

Tests

All tests were run on an Aurora instance r6g.large with a secondary availability zone. The test was composed of:

        Four connections

    • #1 to perform DDL
    • #2 to perform insert data in the table I am altering
    • #3 to perform insert data on a different table 
    • #4 checking the other node operations

In the Aurora instance, a …

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Zero impact on index creation with Aurora 3

Last quarter of 2021 AWS released Aurora version 3. This new version aligns Aurora with the latest MySQL 8 version porting many of the advantages MySQL 8 has over previous versions.

While this brings a lot of new interesting features for Aurora, what we are going to cover here is to see how DDLs behave when using the ONLINE option. With a quick comparison with what happens in MySQL 8 standard and with Group Replication. 

Tests

All tests were run on an Aurora instance r6g.large with secondary availability zone.
The test was composed by:

        4 connections

    • #1 to perform ddl
    • #2 to perform insert data in the table I am altering
    • #3 to perform insert data on a different table 
    • #4 checking the other node operations

In the Aurora instance, a sysbench …

[Read more]
Zero impact on index creation with Aurora 3

Last quarter of 2021 AWS released Aurora version 3. This new version aligns Aurora with the latest MySQL 8 version porting many of the advantages MySQL 8 has over previous versions.

While this brings a lot of new interesting features for Aurora, what we are going to cover here is to see how DDLs behave when using the ONLINE option. With a quick comparison with what happens in MySQL 8 standard and with Group Replication. 

Tests

All tests were run on an Aurora instance r6g.large with secondary availability zone.
The test was composed by:

        4 connections

    • #1 to perform ddl
    • #2 to perform insert data in the table I am altering
    • #3 to perform insert data on a different table 
    • #4 checking the other node operations

In the Aurora instance, a sysbench …

[Read more]