Planet MariaDB

This week I came across an old known issue reported in May 2010: Master/Slave Replication with binlog_format = ROW and tables without a Primary Key is a bad idea! Especially if these tables are huge. Why this is a bad idea is described in the bug report #53375: if one runs DML on a table that has no indexes, a full table scan is done. with RBR, the slave might need to scan the full table for *each* row changed. The consequence of this behaviour is that the Slave starts lagging. It was further mentioned: Worst part is that PROCESSLIST,… Read more

This week I came across an old known issue reported in May 2010: Master/Slave Replication with binlog_format = ROW and tables without a Primary Key is a bad idea! Especially if these tables are huge. Why this is a bad idea is described in the bug report #53375: if one runs DML on a table that has no indexes, a full table scan is done. with RBR, the slave might need to scan the full table for *each* row changed. The consequence of this behaviour is that the Slave starts lagging. It was further mentioned: Worst part is that PROCESSLIST,… Read more

Backups are a key part of a disaster recovery strategy, making sure you can continue or restore your business in case of an unwanted event with your data. We always work on trying to improve Percona XtraBackup reliability, always favoring consistency, attempting to make unwanted outcomes be noticed as earlier as possible in the process. […]… Read more

Mydbops propounds free webinars & meetups about MySQL, MongoDB, and PostgreSQL, the major three opensource databases.  What greater thing can we give to our community than to diversify their skill sets and improve their craftsmanship by providing free Webinars with niche topics, illustrations, Q&A, and, most importantly, more fun as we work together to sharpen our … Continue reading Mydbops MyWebinar 13th edition – Speaker Announcement →… Read more

MariaDB SkySQL’s new release makes getting started free, fast and easy without requiring a credit card…. Read more

MariaDB is pleased to announce the immediate availability of the MariaDB Connector/Java 2.7.5 GA release. Download Now Release Notes MariaDB … Continued… Read more

In this blog we are going to see how to create a link to a remote server and use it to access multiple tables at once.In the previous blog we have seen how to establish a remote connection between Docker containers.The way we did it was to specify the connection string to reference a single table only.But what if we need more tables, what if need a whole database? … Continue reading "Create a link to a remote server and access data using CONNECT SE" The post Create a link to a remote server and access data using CONNECT SE… Read more

A year ago, I blogged about An Unprivileged User can crash your MySQL Server.  At the time, I explained how to protect yourself against this problem.  A few weeks ago, I revisited this vulnerability in a follow-up post in which I explained the fix, claimed that the MySQL 5.7 default configuration for Group Replication is still problematic, and explained a tuning to avoid the vulnerability.  In… Read more

Our team has reimplemented iibench as a sysbench workload. You can read more about it on the project Github page…. Read more

The most common issue when using row-based replication (RBR) is replication lag due to the lack of Primary keys. The problem is that any replicated DML will do a full table scan for each modified row on the replica. This bug report explains it more in-depth: https://bugs.mysql.com/bug.php?id=53375 For example, if a delete is executed on […]… Read more

Recently we published the first part (m5, m5a, m6g) and the second part (C5, C5a, C6g) of research regarding comparing Graviton ARM with AMD and Intel CPU on AWS. We selected general-purpose EC2 instances with the same configurations (amount of vCPU in the first part). In the second part, we compared compute-optimized EC2 instances with […]… Read more

Introduction In part 2, “De-Mystifying Tungsten Cluster Topologies: CAA vs. MSAA,” we covered the difference between Composite Active/Active (CAA) and Multi-Site Active/Active (MSAA) topologies. In this blog post we will highlight the key differences between Composite Active/Passive (CAP), Composite Active/Active (CAA) and Dynamic Active/Active (DAA) topologies. In the below table, we provide a quick summary of the key points for comparison:   Composite Active/Passive Composite Active/Active Dynamic Active/Active Pros Simplicity of application adoption and near fully automated continuous operations. Fully automated continuous operations and ability to write to multiple Primaries simultaneously. Fully automated continuous operations and simplicity of application adoption… Read more

Editors and technical reviewers suggested that I cover how to configure MySQL query metrics in chapter 1 of Efficient MySQL Performance, but I deferred because it was out of scope for the book, which focuses on engineers using MySQL, not DBAs. As such, there’s only a note in chapter 1 that says: “Ask your DBA or read the MySQL manual.” But I’ll cover the topic here because that’s what this blog post series is for: behind the book…. Read more

I had already written many blog posts about bpftrace. All my public talks devoted to bpftrace included a slide about "problems", and one of them usually sounded like this:…access to complex structures (bpftrace needs headers)… So, today I decided to demonstrate how to resolve this minor problem. As an example I tried to reproduce gdb debugging steps from this older post. I want to trace and report table and row level locks set during execution of various SQL statements against InnoDB tables in MariaDB Server 10.6.6 built from more or less current GitHub code. To reduce the performance impact I'll… Read more

Install a database server. Give the application team an endpoint. Set up backups and monitor in perpetuity. This is a pattern I hear about regularly from DBAs with most of my enterprise clients. Rarely do they get to troubleshoot or work with application teams to tune queries or design schemas. This is what triggers the […]… Read more