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Displaying posts with tag: mariadb (reset)
MariaDB ColumnStore

Last month, MariaDB officially released MariaDB ColumnStore, their column store engine for MySQL. This post discusses what it is (and isn’t), why it matters and how you can approach a test of it.

What is ColumnStore?

ColumnStore is a storage engine that turns traditional MySQL storage concepts on their head. Instead of storing the data by row, a column store stores the data by column (obviously). This provides advantages for certain types of data, and certain types of queries run against that data. See my previous post for more details on column-based storage systems.

ColumnStore is a fork of InfiniDB and carries forward many of the concepts behind that product. InfiniDB ceased operations in 2014. With the front end managed through MariaDB, you get access to …

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perf Basics for MySQL Profiling

Oprofile was widely used for MySQL profiling on Linux in the past. But since 2010 and 2.6.31 Linux kernels another profiler, perf, gets increasing popularity. It uses performance counters (CPU hardware registers that count hardware events such as instructions executed) subsystem in Linux. perf is capable of lightweight profiling. It is included in the Linux kernel, under tools/perf (so features available depends on kernel version), and is frequently updated and enhanced.

So, probably perf is the future of profiling on Linux and it makes sense to discuss its basic usage for profiling MySQL servers. For detailed discussions of features provided, numerous examples (not related to MySQL) and links I suggest to read …

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oprofile Basics for MySQL Profiling

In my previous post I've presented a list of bugs reported by famous MySQL developers, DBAs, users and support engineers who used oprofile to find the problem or root cause of the problem they studied. I assume that some of my readers would like to follow their steps and try to use this tool while working on MySQL performance problems. Bug reports I mentioned contain outputs and, rarely, just some commands used. That's why I decided to write a kind of a basic "Howto" document. The tool does have a detailed enough manual, but few basic steps for quick use of oprofile to study MySQL-related problems should still help. At least I had always considered …

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Fun with Bugs #47 - On Some Bugs Found Using oprofile

Users had to identify the reasons for MySQL performance problems somehow well before famous Performance Schema appeared in MySQL 5.5.3, and even before Domas invented his Poor Man's Profiler. Poor users had to use some OS-level tools, and among these tools the most important one was, probably, oprofile.

oprofile is a system-wide statistical profiling tool for Linux available since 2001 and 2.4.x kernels. It was applied to MySQL for many …

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How upgrading MariaDB Server failed because 50M warnings were ignored

This post is part of the series "please do not ignore warnings in MySQL/MariaDB".  The previous post of the series can be found here.

In this post, I will present why ignoring warnings made me lose time in upgrading MariaDB Server.  I think this war story is entertaining to read and it is also worth presenting to people claiming that ignoring warnings is no big deal.

A few months ago, I was in

Why I wrote "please do not ignore warnings" and "to always investigate/fix warnings" (in MySQL/MariaDB)

In a last post, I wrote the two following sentences:

please do not ignore warnings always investigate/fix warnings

I realized that without context, this might be hard to understand.  In this post, I want to give more background about these two sentences.

In my work, I have seen problems solved (wrongly) by ignoring warnings.  Some example that comes to my mind:

upgrading to a new MySQL

PL/SQL in MariaDB

The Oracle 12c manual says "Oracle PL/SQL provides functionality equivalent to SQL/PSM:2011, with minor syntactic differences, such as the spelling or arrangement of keywords." Yes, and English provides functionality equivalent to Russian, except all the words are spelled differently and in different order. Seriously, since Oracle has PL/SQL and MariaDB has SQL/PSM, their stored procedures and functions and triggers and anonymous blocks -- hereinafter "code blocks" -- look different.

But that's changing.

There's a boatload of Oracle compatibility sauce in MariaDB 10.3, and part of it is PL/SQL code blocks, which is what I'll look at here. MariaDB 10.3 is not released and might not be released for a long time, but the source code is public. I downloaded it with
git clone -b bb-10.2-compatibility …

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Oracle MySQL and the funny replication breakage of Friday, January 13

In my previous post, I talked about a funny replication breakage that I experienced with MariaDB.  So what about different versions of MySQL... > SELECT version(); +------------+ | version() | +------------+ | 5.6.35-log | +------------+ 1 row in set (0.00 sec) > SELECT * FROM test_jfg; +----+--------+-------------+ | id | status

Funny replication breakage of Friday, January 13

A funny replication breakage kept me at the office longer than expected today (Friday 13 is not kind with me).

So question of the day: can you guess what the below UPDATE statement does (or what is wrong with it)?

> CREATE TABLE test_jfg ( id INT NOT NULL AUTO_INCREMENT PRIMARY KEY, status ENUM('a','b') NOT NULL DEFAULT 'a', txt TEXT); Query OK, 0

What products & improvements are new on AWS?

Amazon is releasing new products & services to it’s global cloud compute network at a rate that has all of our heads spinning. Join 32,000 others and follow Sean Hull on twitter @hullsean. Here’s new stuff worth mentioning around databases & data. 1. For ETL – AWS GLUE Moving data from your transactional MySQL or … Continue reading What products & improvements are new on AWS? →

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