Common Table Expressions (CTEs) are a very useful tool and
frankly a big improvement on sub-queries. But there are
differences in how they are implemented in MySQL and
MariaDB. That is not too surprising since the code
fork many years ago. Different engineers implementing the same
idea will have different approaches (and sometimes results). But
differences in implementation are often important and, in this
case, shockingly different.
Jesper Wisborg Krogh at Oracle OpenWorld and CodeOne gave a
series of presentations and hands on labs that were excellent. He
is an amazing Support Engineer and a great presenter of material
at conferences. In the lab for Common Table Expressions he
did point out to me an interesting problem in MariaDB's
implementation of CTEs.
The Problem In a Nutshell
On the PostgreSQL Wiki, there is a
an SQL query (requires PostgreSQL 8.4 or MySQL 8.0) that …
Hello, open source database enthusiasts at Percona Live Europe 2018! There is a lot to see and do today, and we’ve got some of the highlights listed below.
On Facebook? Go here for some pics that captured the action
on Percona Live Europe 2018 Tutorials day (Monday, Nov. 5,
2018).
Download the Conference App
We apologize for the confusion yesterday on the app but can assure you, the schedule and timings have been updated! If you haven’t already downloaded the app, go to the app store and download the official Percona Live App! You can view the schedule, be alerted for any …
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Quickly Add a Node to an InnoDB Cluster or Group Replication (Shutterstock)
In this blog, we’ll look at how to quickly add a node to an InnoDB Cluster or Group Replication using Percona XtraBackup.
Adding nodes to a Group Replication cluster can be easy (documented here), but it only works if the existing nodes have retained all the binary logs since the creation of the cluster. Obviously, this is possible if you create a new cluster from scratch. The nodes rotate old logs after some time, however. Technically, if the
gtid_purged
set is non-empty, it means you will need another method to add a new node to a cluster. You also …
[Read more]Paytrail
“Galera Cluster has supported our growth all the way from a small number of transactions to high volume traffic. Since 2012 our payment service with Galera has processed over 4 billion euros worth of product and service sales. Today we help 10 000+ webshops and online services in several countries to provide a pleasant shopping experience to their customers”
THINQ
“We’re very happy how Galera Cluster facilitated automated failover eliminating downtime for THINQ services that programmatically route millions of phone calls. The comprehensive Codership documentation includes, for example, the AppArmor package settings necessary to make Galera Cluster nodes more secure. ”
North Carolina based, THINQ is a cloud-based software company that develops Business as a Service (BaaS) solutions for the telecommunications industry. Partners …
[Read more]A framework can be a great way to allow you to spend more time on the actual application or web site and less time on standard tasks. It can also greatly reduce the amount of custom code needed. Django is one of the best known web frameworks for Python, and the good news is that it works out of the box with MySQL Server 8 and MySQL Connector/Python 8. This blog will look at how to use Django with MySQL 8.
There actually is very little to get Django to work with MySQL 8.
Just install it, configure Django to use MySQL Connector/Python
as a backend, and that’s it. From the Django point of view, you
just have to configure the database option in
settings.py to use MySQL Connector/Python and your
database settings, for example:
DATABASES = { …[Read more]
We are happy to announce that there will be a MySQL Day/MySQL Community Meetup hold in Oracle Buliding in Vienna on November 8th. Please find more details below:
- Date: Thursday, November 8th, 2018
- Time: 7pm - 9pm
- Address: Oracle Office DC Tower 1, Donau-City-Straße 7, 1220 Wien, Österreich
- Meeting room: will be confirmed soon.
- Agenda:
- "Oracle MySQL 8 - The next big thing!" by Carsten Thalheimer the Master Principal Sales Consultant
- Discussion & pizza
- More information & Registration
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 …
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