The benefits of jemalloc versus glibc memory allocator for use with MySQL have been widely discussed. With jemalloc (along with Transparent Huge Pages disabled) there is less memory fragmentation, and thus more efficient resource management of the server memory. For MySQL 5.6, installing jemalloc is enough to enable it when starting the MySQL process. However, for MySQL 5.7 and 8.0.X series, you will need to take a few extra steps.

Enabling jemalloc on Percona Server for MySQL

Installing the jemalloc package is simple for Percona. This is because the library is available on the Percona repository, which is available for both apt and yum package management:

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If you use SQL on a regular basis, then you are well aware that Window Functions are powerful. They allow us to simplify queries that would otherwise be quite the mess. We can provide meaningful insight across rows of data without collapsing the results into a single value. I have written numerous blog posts on Window Functions, many here recently. I decided to make this blog post a compilation of all the Window Function posts I have written, providing a one-stop source for any readers interested in learning more about Window Functions…

Image by Free-Photos from …

Introducing the new Continuent Tungsten Startup Pricing: Give your business the growth infrastructure it deserves with our best-of-breed MySQL HA / DR / Geo-Scale solutions - at Startup Pricing!

Tags: startupstartup pricingContinuent Tungstenmysql hamysql drgeo-scale mysqlMySQL

The tables in PERFORMANCE_SCHEMA (P_S) are not actually tables. You should not think of them as tables, even if your SQL works on them. You should not JOIN them, and you should not GROUP or ORDER BY them.

Unlocked memory buffers without indexes

The stuff in P_S has been created with “keep the impact on production small” in mind. That is, from a users point of view, you can think of them as unlocked memory buffers – the values in there change as you look at them, and there are precisely zero stability guarantees.

There are also no indexes.

Unstable comparisons

When sorting a table for a GROUP BY or ORDER BY, it may be necessary to compare the value of one row to other rows multiple times in order to determine where the row goes. The value compared to other rows can change while this happens, and will change more often the more load the server has. The end …

I am pretty new on the Oracle Cloud Infrastructure technology, so maybe I am talking about something you already know. But anyway I prefer to share this case: it can help if you encounter the same problem as me. Let’s take the risk to have too much information rather than nothing!

The problem

I was doing some tests on the new MySQL Database Service and during the setup I decided to generate my ssh keys via the OCI console:

When I tried to connect via PuTTY or MobaXterm to my compute instance using the opc account and my private key (generated previously), I got the following …

I am pretty new on the Oracle Cloud Infrastructure technology, so maybe I am talking about something you already know. But anyway I prefer to share this case: it can help if you encounter the same problem as me. Let’s take the risk to have too much information rather than nothing!

The problem

I was doing some tests on the new MySQL Database Service and during the setup I decided to generate my ssh keys via the OCI console:

When I tried to connect via PuTTY or MobaXterm to my compute instance using the opc account and my private key (generated previously), I got the …

In this article, we will see the steps to create a snapshot of the existing RDS MySql Instance. Then we will see the steps to restore the snapshot which creates a new RDS Instance. At last, we will clean up the instances and snapshots.

  This is yet another reminder that MySQL 5.6 reaches End of Life status in February 2021.  I have been sending out such reminders since February of 2020. But in my presentations this year when I bring up the 5.6 EOL, there are a lot of users out there that are shocked to hear the news. In one of my November presentations (virtual) I had a very upset audience member who wondered why I was not making more of a big deal out of the EOL date.

    Wikipedia says ""End-of-life" ("EOL") is a term used with respect to a product supplied to customers, indicating that the product is in the end of its useful life (from the vendor's point of view), and a vendor stops marketing, selling, or rework sustaining it. (The vendor may simply intend to limit or end support for the product.)" 

What does this mean those of you running MySQL 5.6 will not be getting bug fixes, will find it much harder to get support, and …

 Want to learn more about new features in MySQL 8.0? The folks at the Utah Oracle Users Group are opening their December 03, 2020 meeting to all.  It will run from 6:30 PM - 8:00 PM Mountain Time. 

Please RSVP https://us02web.zoom.us/j/89659298608?pwd=QVhIRDcvV0EwNnF

All opinions expressed in this blog are those of Dave Stokes who is actually amazed to find anyone else agreeing with him

How scheduler and script stand in supporting failover (Percona and Marco example) 

In part one of this series,  I had illustrated how simple scenarios may fail or have problems when using Galera native support inside ProxySQL. In this post, I will repeat the same tests but using the scheduler option and the external script.

The Scheduler

First a brief explanation about the scheduler.

The scheduler inside ProxySQL was created to allow administrators to extend ProxySQL capabilities. The scheduler gives the option to add any kind of script or application and run it at the specified interval of time. The scheduler was also the initial first way we had to deal with Galera/Percona XtraDB Cluster (PXC) node management in case of issues. 

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