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Showing entries 1 to 10 of 687 10 Older Entries

Displaying posts with tag: drizzle (reset)

Performance impact of MySQL query cache on modern hardware
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Recently, Morgan has been writing on deprecating some MySQL features and inspired by that while working on MySQL on POWER, I wondered “What is the impact of the MySQL query cache on modern hardware?”

We’ve known for over six years (since before we started Drizzle) that the …

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1 million SQL Queries Per Second: MySQL 5.7 on POWER8
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I’ve previously covered MySQL 5.6 on POWER (with patch), MySQL 5.6 Performance on POWER8 (spoiler: new performance record) and MySQL 5.7 on POWER.

Of course, The postings on this site are my own and don’t necessarily …

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Efficiently writing to a log file from multiple threads
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There’s a pattern I keep seeing in threaded programs (or indeed multiple processes) writing to a common log file. This is more of an antipattern than a pattern, and is often found in code that has existed for years.

Basically, it’s having a mutex to control concurrent writing to the log file. This is something you completely do not need.

The write system call takes care of it all for you. All you have to do is construct a buffer with your log entry in it (in C, malloc a char[] or have one per thread, in C++ std::string may do), open the log file with O_APPEND and then make a …

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Caring about stack usage
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It may not be surprising that there’s been a few projects over the years that I’ve worked on where we’ve had to care about stack usage (to varying degrees).

For threaded userspace applications (e.g. MySQL, Drizzle) you get a certain amount of stack per thread – and you really don’t want to bust that. For a great many years now, there’s been both a configuration parameter in MySQL to set how much stack each thread (connection) gets as well as various checks in the source code to ensure there’s enough free stack to do a particular operation (IIRC open_table is the …

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The joy of Unicode
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So, back in late 2008, rather soon after we got to start working on Drizzle full time, someone discovered unicodesnowmanforyou.com, or:

Since we had decided that Drizzle was going to be UTF-8 everywhere,(after seeing for years how hard it was for people to get character sets correct in MySQL) we soon added ☃.test to the tree, which tried a few interesting things:

CREATE TABLE ☃; CREATE DATABASE ☃; etc etc

Because what better to …


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Is Drizzle dead?
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Yesterday someone opened a Launchpad question asking "is Drizzle dead?".  I have answered that question on Launchpad but wanted to blog about it to give a bit of background context.

As I am sure most of the people who read this know, Drizzle is an Open Source database which was originally forked from the alpha version of MySQL 6.0.  At the time it was an extremely radical approach to Open Source development, many features were stripped out and re-written as plugins to turn it into a micro-kernel style …

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Ghosts of MySQL Past: Part 2
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This continues on from my post yesterday and also contains content from my linux.conf.au 2014 talk (view video here).

Way back in May in the year 2000, a feature was added to MySQL that would keep many people employed for many years – replication. In 3.23.15 you could …

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Converting MySQL trees to git
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I have put up a set of scripts on github: https://github.com/stewartsmith/bzr-to-git-conversion-scripts. Why do I need these? Well… if only bzr fast-export|git fast-import worked flawlessly for large, complex and old trees. It doesn’t.

Basically, when you clone this repo you can run “./sync-BLAH.sh” and it’ll pull BZR trees for the project, convert to git and clean things up a bit. You will likely have to edit the sync-BLAH.sh scripts as I have them pointed at …

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The end of Bazaar
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I’ve used the Bazaar (bzr) version control system since roughly 2005. The focus on usability was fantastic and the team at Canonical managed to get the entire MySQL BitKeeper history into Bazaar – facilitating the switch from BitKeeper to Bazaar.

There were some things that weren’t so great. Early on when we were looking at Bazaar for MySQL it was certainly not the fastest thing when it came to dealing with a repository as large as MySQL. Doing an initial branch over the internet was painful and a much worse …

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Who is working on MariaDB 10.0?
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There was some suggestion after my previous post (Who works on MariaDB and MySQL?) that I look at MariaDB 10.0 – so I have. My working was very simple, in a current MariaDB 10.0 BZR tree (somewhat beyond 10.0.3), I ran the following command:

bzr log -n0 -rtag:mariadb-10.0.0..|egrep '(author|committer): '| \
  sed -e 's/^\s*//; s/committer: //; s/author: //'| \
  sort -u|grep -iv oracle

 

MariaDB foundation/MontyProgram/SkySQL:

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Showing entries 1 to 10 of 687 10 Older Entries

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