Shinguz's blog

MariaDB has some time ago introduced or reused the sql_mode = 'oracle'. What they basically try to do is to implement a subset of the Oracle PL/SQL language. Because we receive more and more request from customers about MariaDB’s Oracle PL/SQL it is worth investigating a bit more in this feature and summarize the state of the art of this topic in this article.

In MySQL 8 the MySQL Data Dictionary was placed inside the InnoDB Storage Engine. This has some impact on multi-tenant applications:

Sometimes customers want to have a very simple Galera Cluster set-up. They do not want to invest into machines and build up the know-how for load balancers in front of the Galera Cluster.

Hello Hal

I do not really get your question. Do you have a good and reproducible example for your question?

We see quite often customers complaining that their Galera Cluster is not stable and “crashes” from time to time. As always one has to investigate before rating.

The receipt above seems also to work with Percona Xtrabackup:

Source: Github: codership / documentation

Codership Blog for Galera Cluster with release announcements.

Some of my colleagues mentioned Window Functions. Maybe it works. But I fear that window functions are not fast because they do some materialization in between? I have to test...

For a fancy application we want to query a chunk of rows from a table and therefore we need the minimum and the maximum of the Primary Key of these rows.
Because InnoDB is an Index Organized Table or Index Clustered Table we know that this access will use the Primary Key. But to be sure and to be compliant with the standard (and compatible) we use and ORDER BY on the Primary Key.

We got some feedback from Paul Campbell about Handler_read_first:

Thought you might like to know that you can get do this without a full index scan (in 5.7 at least) with a query for SELECT MIN(pkey), only the first key is read in this instance. SELECT MAX(pkey) will do the same for Handler_read_last.

FromDual has the pleasure to announce the release of the new version 2.2.3 of its popular Backup and Recovery Manager for MariaDB and MySQL (brman).

Table of Contents

• How to make MariaDB Pull Replication as secure as possible
• MariaDB Push Replication
• Pushing data with the FederatedX Storage Engine and Triggers
• Traffic mirroring with MariaDB MaxScale or ProxySQL

How to make MariaDB Pull Replication as secure as possible

A normal MariaDB Replication is a Pull Replication. This means that a Slave connects to its Master and gathers or better requests Binary Log information from the Master and applies them in a streaming way.

We recently had the situation that a customer complained about the Oom killer terminating the MariaDB database instance from time to time. The MariaDB database configuration was sized quit OK (about 50% of RAM was used for the database) but they did not have swap configured.

An inside view from the MariaDB database instance can be received with:

I just got a note from Markus Makela with the following suggestion:

Recently we had the case that a customer claimed that MariaDB 10.3 Binary Log is using 150% more space on disk than MySQL 5.7 Binary Log. Because I never observed something similar, but to be honest, I did not look to intensively for this situation, we had to do some clarifications.

Because we conduct many customers in MariaDB Galera Cluster upgrades and because these customers sometimes have pretty old MariaDB Galera Cluster set-ups I think it is good to have a rough MariaDB Galera Cluster Upgrade Path.

Hi Oli,

I think that it could be worth mentioning that in MariaDB 10.5, the described problem should no longer exist, thanks to https://jira.mariadb.org/browse/MDEV-19747 removing the code. Also, in older MariaDB versions, https://jira.mariadb.org/browse/MDEV-23720 disables the feature by default.

InnoDB tries to keep pages in Buffer Pool to be fast. If a page is changed by a DML statement (INSERT, UPDATE, DELETE) this change will be done in InnoDB Buffer Pool and not directly on disk. But those changed InnoDB pages residing in InnoDB Buffer Pool must be flushed sooner or later to disk to become persistent. This is done by the InnoDB background writer thread(s) (default 4).

Because upgrading from MariaDB 10.4 to MariaDB 10.5 (non-clustered) seems not to be a problem
[ 1
] we take the challenge and try to create a receipt based on the MariaDB 10.3 to MariaDB 10.4 Galera Cluster upgrade documentation
[ 3
]: