Running many benchmarks on fast storage (FusionIO, SSDs) and multi-cores CPUs system I constantly face two contention problems.

So I suspect it's going to be next biggest issues to make InnoDB scaling on high-end system.

This is also reason why in benchmarks I posted previously CPU usage is only about 50%, leaving other 50% in idle state.

First problem is index->lock mutex.
InnoDB uses single mutex per index, so when you run mixed read / write queries, InnoDB locks index for write operation and thus keeps all selects waiting when update/insert is done. This is implemented in this way because write operation may cause B-Tree page split, and InnoDB needs to move records between pages to finish operation. It is getting even worse when for write you need to perform some additional IO to bring page into buffer_pool.

What could be done there internally: there is B-Tree lock free or only page-level lock …

If you update to the latest build now, you will find a bunch of new SSL fields, used to select certificates and keys needed to connect to a SSL featured MySQL server. Thanks to SuperNiFF for posting most relevant code.



Second thing is, you can specifiy a startup script now. This is a simple way to execute one or more customized queries automatically when you connect to a server. Just select a SQL file here and HeidiSQL runs that as soon you have a connection established.

If you have been reading the Kontrollbase performance reports and noticed that one alert says your connection usage vs max connections ration is too high but then recommends you to decrease the max_connections variable, then you will find this fix handy. Its two simple queries that execute on the Kontrollbase schema to update the max_connections [...]

From Stack Overflow:

Here is my schema:

I need to find the sids of suppliers who supply every red part or every green part.

This task requires matching the sets.

We need to compare two sets here: the first one is the set of the parts of given color; the second one is the set of parts provided by a given supplier. The former should be the subset of the latter.

Unlike other engines, …

This is a simple matter with a simple solution that might help someone save time and confusion. Emacs wasn’t coloring my comments correctly so I went ahead and had it change them to red-italic. If you are having similar issues you can drop the following into your home directory’s .emacs file. Enjoy. Keep in mind that if you are using emacs in a terminal session as opposed to the X-server gui then you will not see the italics.


(global-font-lock-mode 1)
(custom-set-variables
'(gud-gdb-command-name "gdb --annotate=1")
'(large-file-warning-threshold nil))
(custom-set-faces
'(font-lock-comment-face ((((class color) (background light)) (:foreground "red" :slant italic)))))


Brian Aker, a brilliant helpful duder, who I learn a lot from. Gives a great talk about what is NoSQL explained in a way for database guys. I warn you, there are some points in this video where you can't hear Brian due to the audience "participation" but you should get the content.

As a part of Global Ignite Week I will be doing an updated "Guide to NoSQL". Ignite Seattle will be taking place at the King Theater in Bell Town next Thursday, March 4th.

I'm hoping for better audio this time :)

Applying binary logs to a MySQL instance is not particularly difficult, using the mysqlbinlog command line utility:

$> mysqlbinlog mysql-bin.000003 > 03.sql
$> mysql < 03.sql

Turning off binary logging for a session is not difficult, from the MySQL commandline, if you authenticate as a user with the SUPER privilege:

mysql> SET SESSION sql_log_bin=0;

However, sometimes you want to apply binary logs to a MySQL instance, without having those changes applied to the binary logs themselves. One option is to restart the server binary logging disabled, and after the load is finished, restart the server with binary logging re-enabled. This is not always possible nor desirable, so there’s a better way, that works in at least versions 4.1 and up:

The mysqlbinlog utility has the --disable-log-bin option. All the option does is add the SET …

Changes (as compared to 3.71) include:

Features:
* The number of builds for Linux has been increased to the double number of what it was before.  In addition to the builds based on glibc version 2.3 we now distribute builds based on glibc 2.5.  Also we add builds for use with even older glibc 2.3 based Linux that what we had before. There are now builds based on both glibc-2.3.2  and 2.3.4 (the one based on 2.3.4 is the one we had before). We had a few  reports of random crashes (typically occurring up to a few times per week) occurring on recent 64 bit CentOS servers and in one case also a RHEL5.  The glibc 2.5-based build fixes this. Although we only had such reports on 64 bit Linux of  ‘Red Hat Family’ we also included 64 bit tar.gz for all Linux platforms and 32 bit RPM builds.  The general advice on which build (glibc 2.3-based versus 2.5-based) should be …

Just a note that my personal blog resides on lentz.com.au/blog/

The story is this… I first started my blog when at MySQL AB, the Community Relations gig. It was a mix of personal and MySQL-related stuff, and hosted at LiveJournal. Last year we managed to migrate all the LiveJournal data to the Open Query blog instance, but naturally there it’s not really suitable to write about non-OQ stuff. So I’ve cloned that instance and am deleting the posts that are really only OQ/MySQL-related. Some business/development topics that refer to MySQL as an example will stay.

In any case, this allows me to scribble about my (bio)diesel car, gardening, cooking, bushwalking and all that without bothering the Open Query blog readers Those of you who are interested can subscribe to both. Easy!