In MySQL Cluster a statement like
update t1 set counter=counter+1 where pk=1
can be executed in a few different ways with great difference in
performance.
If we do it from the MySQL server then the update is implemented
as:
read_ex(counter) ; //one round trip to MySQL Cluster, read with
exclusive lock
counter++
update(counter); //one round trip to MySQL Cluster, update -
write back
If we are using the NDBAPI (Cluster Direct API) we could
implement it as above as well, but for the operation above, the
NDBAPI offers a way of performing the update in just one round
trip! This can be done using Interpreted Programs, which are
instructions defined in your NDBAPI application and upon execute,
sent to the ndbd kernel and executed there. Cool. What I will
show you here is how to do an update using the interpreted
program, which is called …
Few days ago I’ve started migration of some of my non-critical servers to Debian Etch (from Sarge). Just after first apt-get update && apt-get dist-upgrade, when apt has been upgraded, I noticed really strange (as for me) error: when I’ve tried to do “apt-get update” it worked fine, but there was annoying message like following:
# apt-get update
......
Fetched 5562B in 13s (421B/s)
Reading package lists... Done
W: There are no public key available for the following key
IDs:
A70DAF536070D3A1
W: You may want to run apt-get update to correct these
problems
#
UPDATE: Thanks to Kurt Fitzner we know, that:
There is already a mechanism to do this automatically:
$ apt-key update
This will obtain the necesary keys and import them. No need to go through gpg directly.
After not so …
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Jon Stokes writes about this on Arstechnica,
looking at a forthcoming Virginia Law Review paper entitled
"The
Piracy Paradox: Innovation and Intellectual Property in Fashion
Design," in which two law professors investigate how the
fashion industry manages to thrive despite rampant copying of
clothing designs.
While it's not simply applicable to other areas (such as
software), quite a few interesting observations are made - the
most interesting (to me) is that making a generalistic
presumption about needing very strong IP protection in order to
drive innovation is just plain wrong, as the fashion industry
proves. It may apply to other areas, but it's clearly not a
universal rule.
I actually think that fashion and software have a lot in common,
particularly in terms of the …
Continuent Sequoia, an open source database clustering solution, is part of a suite of Continuent.org open source projects that deliver high availability for virtually any database environment, including MySQL and its all engines (MyISAM, InnoBD, SolidDB, etc.).
So I've expanded the scope of the NDB/Python wrappers I was working on. Now I've got Python, Perl and C# wrappers working, at least for basic functionality. I've setup a trac instance and put a roadmap and all of that type of stuff up. If you are interested in hacking, let me know and we can talk about subversion access and all that.
For the moment, I've turned off code downloading. I'll post again when I've enabled it again.
One of the things about working for an Open Source company, is
that I
feel the "need to be careful" about what post if the post
involves a
competitor (or even a competing project). The problem of course
is
that I deal with many open source communities that are not
related to
MySQL at all (or my work on MySQL), so I do notice trends that
have
nothing to do with databases.
I need a secret identity to post comments about MySQL competitors
:)
Ah, screw it!
Last week I went to go buy a new 1u for project from ABMX
(http://www.abmx.com/). ABMX is my current favorite
white box vendor. I've
never had an issue with their computers and they are priced
right.
What do I notice in the checkout box?
The linux that comes default is "Oracle Enterprise Linux
4.4".
My Link: …
A new poll we’re running on the MySQL web site shows that a lot of folks still aren’t familiar with the strict mode/sql mode setting that was introduced with MySQL 5.0. The sql_mode parameter allows you to have MySQL better enforce data integrity in terms of what data is accepted/rejected by the server. Not having this capability produced a number of gotchas in previous MySQL versions, but in 5.0, these all go away.
The sql_mode config parameter is very flexible in terms of how strong/lax you want to be with respect to having MySQL enforce data integrity. For more information on all the options available to you with the sql_mode parm, see the MySQL Manual. And for a quick primer on sql_mode and how to use it, you can …
[Read more]A kind soul has contributed a Debian/Ubuntu package for the innotop MySQL and InnoDB monitor. Thanks Sebastien Estienne!
In the past life was easy in MySQL. Both CHAR and VARCHAR types meant the same, only being difference in the sense of fixed or dynamic row length used. Trailing spaces were removed in both cases.
With MySQL 5.0 however things changed so now VARCHAR keeps trailing spaces while CHAR columns do not any more. Well in reality CHAR columns are padded to full length with spaces but it is invisible as those trailing spaces are removed upon retrieval. This is something you need to watch both upgrading to MySQL 5.0 as well as designing your applications - you should keep into account if you mind trailing spaces stored choosing VARCHAR vs CHAR in addition to fixed length vs dynamic level rows and space spent for column size counter.
There is more fun stuff with trailing spaces. When comparison is done trailing spaces are always removed, even if VARCHAR column is used which is pretty counterintuitive. So “a “=”a”=”a ” for all …
[Read more]MySQL CEO Mårten Mickos received a Nokia Foundation Award for his leadership in advancing open source technology. The Nokia Foundation was formed in 1995 in Finland to support the scientific development of information and telecommunications technologies. Previous recipients of the annual award include Linus Torvalds, and professor Moncef Gabbouj from the Tampere Uninversity of Technology in Finland.
The telecommunications industry in general and Nokia in particular, have been huge beneficiaries of open source technology, with extensive use of Linux and the MySQL to power …
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