As in every quarter of the year Oracle has released yesterday its recommendation for the MySQL security updates. This is called, in Oracle terminology, Critical Patch Update (CPU) Advisory.

This CPU is published for all Oracle products. But FromDual is only interested in MySQL related topics. So let us concentrate on those.

This time 25 fixes with a maximum score of 8.1 (out of 10.0) were published.

6 of theses 25 vulnerabilities are exploitable remotely over the network without authentication (no user credentials required)!

The following MySQL products are affected:

…

In this post, we’ll look at updating and deleting rows with ClickHouse. It’s the second of two parts.

In the first part of this post, we described the high-level overview of implementing incremental refresh on a ClickHouse table as an alternative support for UPDATE/DELETE. In this part, we will show you the actual steps and sample code.

Prepare Changelog Table

First, we create the changelog table below. This can be stored on any other MySQL instance separate from the source of our analytics table. When we run the change capture script, it will record the data on this table that we can consume later with the incremental refresh script:

CREATE TABLE `clickhouse_changelog` (
  `db` varchar(255) NOT NULL …

Join Percona’s Product Manager Michael Coburn as he presents MySQL Troubleshooting and Performance Optimization with Percona Monitoring and Management (PMM) Part 2 on Thursday, January 18, 2018, at 11:00 am PST / 2:00 pm EST (UTC-8).

Register Now

Tags: Percona Monitoring and Management, PMM, Monitoring, MySQL, Performance, Optimization, DBA, SysAdmin, DevOps
Experience Level: Expert

Optimizing MySQL performance and troubleshooting MySQL problems are two of the most critical and challenging tasks for …

Now that we have the new MySQL community workspace on Slack we opened a workspace channel for our users there. If you have a question or problems with Workbench this is the place to be.

This channel will soon replace our old #workbench IRC channel.

Severalnines is happy to announce that our new whitepaper “MySQL on Docker - How to Containerize Your Database” is now available to download for free!

While the idea of containers has been around since the early days of Unix, Docker made waves in 2013 when it hit the market with its innovative solution. Docker allows you to add your stacks and applications to containers where they share a common operating system kernel. This lets you have a lightweight virtualized system with almost zero overhead. Docker also lets you bring containers up or down in seconds, making for …

As a tradition (and follow up of the previous announcement posted on Oct 23, & Sep 15, 2017) we would like to inform you about a conferences & events we - MySQL Community Team - are attending together with MySQL experts in the first quarter of 2018. Please be aware that the list does not have to be final, during the time more events could be added or some of them removed.  

January 2018:  

• OpenSource Conference (OSC) Osaka, Japan, January 26-27, 2018

  • We are happy to announce MySQL attendance and MySQL session at the OSC event in Osaka, Japan. Please do not miss to …

Replication lag occurs when the slaves (or secondaries) cannot keep up with the updates occuring on the master (or primary). Unapplied changes accumulate in the slaves' relay logs and the version of the database on the slaves becomes increasingly different from that of the master.

To work out what's causing the lag, you must determine which replication thread is getting backed up. Replication relies on three threads per master/slave connection: one is created on the master and two are created on the slave.

• The Slave I/O Thread. When you issue START SLAVE on a slave server, the slave creates this thread which connects to the master and requests a copy of the master's binary log.
• The Binlog Dump Thread. When the slave connects to the master, the master uses this thread to send the slave the contents of its binary log.
• The Slave SQL …

The two status variables Queries and Questions can sometimes cause confusion. On the face of it, both appear to count the number of times a query is executed on the server.

Each variable has both session and global scope, meaning that you can get statistics for both the current connection and for all connections. You can reset the session variables by executing FLUSH STATUS, but resetting the global variables requires a server restart.

All good so far. However, the way in which these variables are incremented is not always intuitive.

For one thing, everything in MySQL is a Question. Any operation you perform, including checking the status of a server variable is a Question. Even checking the number of Questions issued by your session is, in itself, a Question:

mysql> SHOW STATUS LIKE 'Questions'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | Questions | 2 | …

In this blog post, we’ll look at ProxySQL firewalling (how to use ProxySQL as a firewall).

Not long ago we had an internal discussion about security, and how to enforce a stricter set of rules to prevent malicious acts and block other undesired queries. ProxySQL came up as a possible tool that could help us in achieving what we were looking for. Last year I wrote about how to use ProxySQL to stop a single query.

That approach may be good for few queries and as a temporary solution. But what can we do when we really want to use ProxySQL as an SQL-based firewall? And more importantly, how to do it right?

First of all, let us define what “right” can be in this context. …

On April 4th 2012 Xtrabackup 2.0 was released in to GA by Percona along with a new streaming feature called xbstream. This new tool allowed for compression and parallelism of streaming backups when running xtrabackup or innobackupex without having to stream using tar, then pipe to gzip or pigz, then pipe to netcat or socat to stream your backup to the recipient server. This resulted in …