as announced in the blog posted on Oct 18, 2018 we would like to just remind you about places and shows where you can find us this really busy week... We are ready for following shows:

• PerconaLive in Frankfurt, Germany on November 5-7, 2018

  • as previously announced there are plenty of our MySQL experts, our friends from sales & Fred Descamps representing MySQL community at PerconaLive, Frankfurt which started today. Right now Fred Descamps & Kenny Grip are having a tutorial on "MySQL InnoDB Cluster in a Nutshell : The Saga Continues with …

Version 8.0.12 added many great new features to MySQL. One of the new features included is the memory instrumentation of the XCom cache, which allows users to view and monitor the memory utilization of the cache by querying Performance Schema (PS).…

There are basically two things which I majorly like about using MyRocks, 1. LSM Advantage – smaller space & lower write amplification and 2. Best of MySQL like replication, storage engine centric database infrastructure operations and MySQL orchestration tools. Facebook built RocksDB as an embeddable and persistent key-value store with lower amplification factor () compared to InnoDB. Let me explain a scenario were InnoDB proves less efficient compared to RocksDB in SSD:
We know InnoDB is constrained by a fixed compressed page size. Alignment during fragmentation and compression causes extra unused space because the leaf nodes are not full. Let’s consider a InnoDB table with a compressed page size of 8KB. A 16KB in-memory page compressed to 5KB still uses 8KB on storage. Adding to this, each entry in the primary key index has 13 bytes of metadata (6 byte transaction id + 7 byte rollback pointer), and the …

Recently, I’ve been working with a customer to evaluate the different cloud solutions for MySQL. In this post I am going to focus on maintenance windows and requirements, and what the different cloud platforms offer.

Why is this important at all?

Maintenance windows are required so that the cloud provider can do the necessary updates, patches, and changes to our setup. But there are many questions like:

• Is this going to impact our production traffic?
• Is this going to cause any downtime?
• How long does it take?
• Any way to avoid it?

Let’s discuss the three most popular cloud provider: AWS, Google, Microsoft. These three each have a MySQL based database service where we can compare the maintenance settings.

AWS

When you create an instance you can define your maintenance window. It’s a 30 minutes block when AWS can update and restart …

We discussed in our previous blogs about the MySQL-related dashboards. We highlighted the things that a DBA can benefit from by studying the graphs, especially when performing their daily routines from diagnostics, metric reporting, and capacity planning. In this blog, we will discuss the InnoDB Metrics and the MySQL Performance Schema, which is very important especially on monitoring InnoDB transactions, disk/cpu/memory I/O, optimizing your queries, or performance tuning of the server.

This blog touches upon the deep topic of performance, considering that InnoDB would require extensive coverage if we tackle its internals. The Performance Schema is also extensive as it covers kernel and core parts of MySQL and storage engines.

Let’s begin walking through the graphs.

MySQL InnoDB Metrics

This dashboard …

Schema change is one of the crucial tasks in MySQL with huge tables. Schema change can cause locks.

What is gh-ost?

                         gh-ost is a triggerless online schema change for MySQL by Github Engineering .It produces light workload on the master during the schema changes . We need online schema change to alter a table without downtime (locking) in production.pt-online schema change is the most widely used tool for making changes in the tables.gh-ost is just an alternative to pt-online schema change.

Why we have to use gh-ost?

…

PMM (Percona Monitoring and Management) is a free and open-source platform for managing and monitoring MySQL, MongoDB, and PostgreSQL performance. You can run PMM in your own environment for maximum security and reliability. It provides thorough time-based analysis for MySQL® and MongoDB® servers to ensure that your data works as efficiently as possible.

While much of the team is working on longer-term projects, we were able to provide the following feature:

• MySQL and PostgreSQL support for all cloud DBaaS providers – Use PMM Server to gather Metrics and Queries from remote instances!
• Query Analytics + Metric Series – See Database activity alongside queries
• Collect local metrics using node_exporter + textfile …

Very often, database performance is affected by the inability to cache all the required data in memory. Disk IO, even when using the fastest devices, takes much more time than a memory access. With MySQL/InnoDB, the main memory cache is the InnoDB buffer pool. There are many strategies we can try to fit as much data as possible in the buffer pool, and one of them is data compression.

With regular MySQL, to compress InnoDB data you can either use “Barracuda page compression” or “transparent page compression with punch holes”. The use of the ZFS filesystem is another possibility, but it is external to MySQL and doesn’t help with caching. All these solutions are transparent, but often they also have performance and management implications. If you are using Percona Server for MySQL, you have yet another option, “column …

If the first time you heard this phrase “parent-child relationship in MySQL”, you went “Ok, anyone else got cool made up names or are we to start brainstorming now”, then this article is for you. For the uninitiated, this might not make much sense. That’s perfectly fine because you do not necessarily need it everyday.

Parent-child relationship in MySQL has to deal with establishing some hierarchal dependencies between records in a database table. In MySQL terms, it means say that “row 12 is the parent of row 14” and stuff like that. In business terms, it will mean establishing a dependency relationship between two similar entities. For example, keeping a record of all the people in a village and matching parents to their children.

So, whenever you hear that phrase, think about a real-world parent-child relationship. For the rest of this article, we are going to explore how to establish said relationships and possible …

MySQL 8.0.13 improves replication lag monitoring by extending the instrumentation for transaction transient errors. These temporary errors, which include lock timeouts caused by client transactions executing concurrently as the slave is replicating, do not stop the applier thread: instead, they cause a transaction to retry.…