From time to time it is necessary to get a bigger picture of your project in terms of size, test coverage, code vs. comments ratio and others (aka metrics). While it is quite difficult to find a good (and free) code coverage tool for C++ there is already a very nice tool package called DPack, which is not only freely available but also gives us some very useful additions in our IDE. One of those features is code statistics.

(more…)

This is the english translation of another article in my german language blog.

How are transactions organized physically

When InnoDB creates a new transaction it is not yet committed. The database has not yet made any promises to the application and so we do not really have to make anything persistent so far.

To be fast InnoDB tries to assemble the transaction in a memory buffer, the innodb_log_buffer. It should be sufficiently large that you actually can assemble such a transaction in memory without needing to write it out in part into the redo log. A size of 1M to 8M is normal.

Once a transaction is to be committed InnoDB has to read the page from disk which contains the image of the row that is being changed. It then has to actually make that change in memory. The changed page is …

This is an english translation of the second part of an article in my german language blog.

Transactions - An InnoDB tutorial

InnoDB does transactions. Meaning: It collects statements working on InnoDB tables and applies them on COMMIT to all tables "at once". Either all of these statements inside one transaction succeed ("commit") or all of them fail ("rollback"), changing nothing.

By default, the database is in AUTOCOMMIT mode. Meaning: The server sees a virtual COMMIT command after each statement. You can disable autocommit completely, or you are starting an explicit transaction inside autocommit using the BEGIN statement.

Continue reading "Transactions - An InnoDB …

MySQL offers a variety of storage engines giving you a lot of flexibility in managing your storage and data access needs. Still I encounter customers who are not using this flexibility when they should, because they lack information about the advantages of Non-MyISAM storage engines or which are using storage engines like InnoDB as if they were using MyISAM.

This is the introductory article in a series of texts that will hopefully once become an InnoDB tutorial. A german version of this article is available in my german language blog.

An InnoDB Tutorial

The InnoDB storage engine is an engine that can be operated ACID compliant, does transactions and foreign key constraints. It is useful for all applications that do online transaction processing or have a high rate of concurrent write accesses for other …

A

I need to compile something and use the MySQL C++ library. I have mysql and mysql++ already compiled, I won’t go over how to do that now.

I added the following code to the top of my source:


#include <mysql++.h>


I got an error

/Users/jhaddad/dev/search_engine/main.cpp:4:21: error: mysql++.h: No such file or directory

Not cool.

How to fix:

In XCode, open up the project settings (under the project menu). Go down to search paths, and you can change your Header search paths to the correct locations where you installed whatever you’re looking for. In this case, mine was /usr/local/includes and /usr/local/mysql/

Next time you try to recompile, you’ll get a different error, this time it should be during Linking. Might look something like the below.

“mysqlpp::Query::store(mysqlpp::SQLQueryParms&)”, referenced from:

…

We're heading into February and that means there's only a few weeks left until the MySQL Conference & Expo early registration expires.  This year's conference promises to be our biggest and best ever.  I suspect that a lot of the hot tutorials on performance tuning and new features will sell out early.  There will be sessions on our various storage engines including InnoDB, Cluster, Falcon and Maria -- a new "MyISAM …

So I don't know who's in charge for this at MySQL so I thought I would just gain their attention by posting here. In addition, I hope this can help others in similar need/situation of serving content on multiple domains.

Basically MySQL serves content on both mysql.com and mysql-press.com which is a NO NO from the point of view of major search engines, most notably Google. Both domains go to the same IP (at least when I checked). This can potentially trigger duplicate content penalty and may even be hurting MySQL's ranking in SERPs (Search engine result pages).

Google seems to be already aware of the other domain.

Right way to serve …

When your company decides that "it is time to build a data warehouse", what thoughts come to mind?1) A magical fairy ice cream land where data is presented in chocolate shells for everyone to digest perfectly;2) A big literal warehouse in the industrial section of town with rusty old containers;3) Another place to put data, which means another place for you to track and monitor additional

This February I`ll be heading to my 8th Fosdem in row.

I went to every single Fosdem so far, some years only one day because of other obligations but I was a round most of the time
During the first couple of years I was pretty active in the FIT team, helping out people to find the right rooms , keeping the fosdem contributions safe with Sven, funding different social events and devroom dinners ,
Later I was in charge of the HPC and Cluster devroom in which we also held the openMosix summits.
And back in 2004 I replaced Moshe at the openMosix Summit standing in front of a great audience at the Janson room.

As Wim just pointed out the Drupal Devroom schedule is out
and it seems like 2008 will …