Looking for a database

[Uno Engborg]

Les Mikesell wrote:
> On Sun, 2006-01-29 at 10:37, Paul Smith wrote:
>
>   
>> Could someone please recommend a nice and well documented database
>> program for a person who has never used a database?
>>     
>
> That's not much to go on when asking for a recommendation.
> The obvious choices on fedora will be MySQL and postgresql
> and between those, postgresql follows the sql standards
> more closely and has a less restrictive license.  Mysql
> might be slightly faster if your usage is mostly read-only.
>   
MySQL being faster is than postgresql is mostly a myth. It may be true
if you have very simple queries or very few connected users. In general
Postgresql is significantly faster.

The MySQL is faster myth, goes back to the MySQL 3 days when that 
actually was the  case,
mostly because MySQL back then didn't support transactions, or 
referential integrety
checks while Postgresql did. (MySQL still doesn't fully support 
referential integrety).

As an example, I created a table containg absolute paths to filenames in my
filesystem, the file size and the md5 sum of the file. I then made a query
to group the files by the md5 sum, and ordering these groups by file size.
On my filesystem that took 12 minutes in postgresql 8.1, and over 16 hours
using mysql 5.

To make it worse, MySQL doesn't have the richness in SQL that postgresql
offers. This often makes queries to MySQL more clumsy. E.g. try do a 
relational
division without using "exept".

Another factor in the choice between MySQL or Postgresql is the fact 
that Oracle have bought the innodb
storage engine that is the main the one you need to use if you want to 
come even close to the feature set of
postgresql does. In my mind, this creates some uncertainty for the 
future. It gives a competitor the means
to shut down commersial licensing or raise the prices. That can never be 
good.

If I was to chose between Postgresql and another free database it would 
be between Postgresql and Firebird,
where I would go for firebird for embedded solutions or when I needed to 
have databases that resided in
just one file. Just like Postgresq, Firebird is very close to the sql 
standard, but it is not as feature rich as Postgresql


Regards
Uno Engborg