(In the previous post, Part 4, we covered Compression and Bloom Filters)

In this blog post, we continue on our series of exploring MyRocks mechanics by looking at the configurable server variables and column family options. In our last post, I explained at a high level how compression and bloom filtering are applied to data files as they are initially flushed from immutable memtables and are subsequently passed through the compaction process. With that being covered, we should now have a clear understanding as to how data writing works in MyRocks and can start reviewing how data read requests are handled.

The Read Process

Let’s start off by talking about how read processes are handled at the file level. When a read request comes in, the first thing it needs to do is pull the …

So, typically, a Percona Live (or MySQL User) Conference blog would start off with some mention of the fact that it’s great to be meeting up again in Santa Clara, California, the birthplace of the MySQL User Conference, and a continuous fixture on the yearly MySQL community agenda.

But no, not this time!

On this occasion, the Percona Live Conference blog starts off by pointing out that for the first time since its inception (as far as I can recollect), the MySQL User Conference, i.e. Percona Live Conference (in North America) doesn’t take place in Santa Clara, but rather in Austin, Texas.

Never having been to Texas before myself, I’m looking forward to that innovation, discovering the new surroundings and seeing whether that changes anything or not to the familiar “feel” of a Percona Live / MySQL User Conference.

By the way, there’s still time to …

Percona Live provides the open source database community with an opportunity to discover and discuss the latest open source trends, technologies, and innovations. The conference includes the best and brightest innovators and influencers in the open source database industry.

This year, Percona Live is being held at the Hyatt Regency in Austin, Texas from May 28-30, 2019.

Pythian is proud to be a Silver Sponsor this year, with a full force of our technical experts speaking on a variety of subjects and technologies. These are sessions you won’t want to miss!

If you’re attending, make sure you swing by our booth and meet the Pythian crew. We’ll be happy to answer any questions you have about open source, cloud or anything data related. Our speakers will also be covering the event on social media and we’ll recap the event and their talks here on the Pythian …

(In the previous post, Part 3, we covered Compaction.)

In this blog post, we continue on our series of exploring MyRocks mechanics by looking at the configurable server variables and column family options. In our last post, I explained at a high level how data moves from its initial disk-written files into the full data set structure of MyRocks using a process called compaction. In this post, we’re going to look a little closer at two important features that are leveraged as data cascades down through this compaction process: bloom filters and compression.

Bloom filters

Before we approach how bloom filters are used in MyRocks, we need to know what a bloom filter is. The short definition is that a bloom filter is a space-efficient data structure used to tell you if an …

“Hey, what’s going on with my applications? I installed a newer version of MySQL. I have queries that perfectly run with the older version and now I have a lot of errors.”

This is a question some customers have asked me after upgrading MySQL. In this article, we’ll see what one of the most frequent causes of this issue is, and how to solve it.

We are talking about this error:

ERROR 1055 (42000): Expression #2 of SELECT list is not in GROUP BY clause 
and contains nonaggregated column 'test.web_log.user_id' which is not functionally 
dependent on columns in GROUP BY clause; this is incompatible 
with sql_mode=only_full_group_by

Have you ever seen it?

SQL_MODE

As the first thing let me introduce the concept of SQL_MODE.

MySQL can work using different SQL modes that affect the syntax of the queries and validation checks. Based on the configured value of the …

It’s not long now before we’ll be gathering in Austin TX for this year’s Percona Live event. It’s the only conference of its type dedicated entirely to open source databases – of all marques. From a community perspective, we have a few updates to share.

Community Dinner

We’re happy to say that PlanetScale have stepped up to the plate (!) and are sponsoring this year’s community dinner alongside Percona. This year we are taking to the water and consequently numbers are limited to 100 attendees. If you are keen to join us, be sure to not miss the boat.  😉

The speakers’ perspective

For speakers who also enjoy writing, there’s an …

I have recently created a new library called libMariaS3 for a couple of teams at MariaDB which provides a simple C API to Amazon’s S3. This was created because we needed a library which could link to GPLv2 software and Amazon’s own library is Apache 2.0 licensed which is incompatible.

It is not a perfect code base because I had a very short amount of time to get the first release out but it was a very fun project to work on. It led me to take a quick look this morning at a couple of other things I have created in the past to see where they are at today.

libdrizzle-redux

Around 5 years ago I worked for HP’s Advanced Technology Group and I worked on several different Open Source projects during that time. One of those projects was called libAttachSQL which was a …

(In the previous post, Part 2, we covered Initial Data Flushing.)

In this blog post, we continue our series of exploring MyRocks mechanics by looking at the configurable server variables and column family options. In our last post, I explained at a high level how data moves from immutable memtables to disk. In this post, we’re going to talk about what happens to that data as it moves through the compaction process.

What is Compaction?

One of the philosophies of MyRocks is “write the data quickly and sort out data organization later”, which is pretty far removed from engines like InnoDB that take the approach of “continuously organize data on disk so it’s optimal as soon as possible”. MyRocks implements its philosophy in a way that is heavily reliant on a process …

(In the previous post, Part 1, we covered Data Writing.)

In this blog post, we continue on our series of exploring MyRocks mechanics by looking at configurable server variables and column family options. In our last post, I explained at a high level how data first entered memory space and in this post, we’re going to pick up where we left off and talk about how the flush from immutable memtable to disk occurs. We’re also going to talk about how newly created secondary indexes on existing tables get written to disk.

We already know from our previous post in the series that a flush can be prompted by one of several events, the most common of which would be when an active memtable is filled to its maximum capacity and is rotated into immutable status.

When your immutable memtable(s) is ready …

I have written previous blog posts about Oracle Cloud OCI and this series continues. My post titled with Iaas Getting Started was to get us acquainted with important security-focused items like Compartments and network Services like NAT and Internet-Gateways. Then I posted about building MySQL on Compute with Scripting using a mix of OCI Web console navigation… Read More »