Amarok Datenbank-Backend

[Tobias G. Pfeiffer]

Hi!

Am Samstag, 8. September 2007, 09:12 schrieb Maximilian Kossick:
> In my planned DB schema, the tags table was basically renamed to tracks.
> The other two major changes are the introduction of the url table (although
> i'm not quite convinced that we actually need it, I need to think about
> this some more) and a modification of the columns of the album table.

As I understood it, there is a 1:1 mapping between a track and a url, so I 
don't think an additional table makes sense here. I noticed that you do not 
ever have primary key constraints for the id columns of tables. At least in 
Postgresql, "primary key" == "unique && not null", i.e. the column is always 
indexed, which provides lookup in logarithmic time. Since accessing rows by 
id (numerical comparison) is much faster than by url or any other string 
(especially when about the first half of this string is the same for all 
tracks, as to be expected in file urls), I recommend setting a primary key 
constraint for all 'id' columns and then try to access table rows by id as 
often as possible.
Since Maximilan said he does not have too much time for Amarok these days, 
I'll try to make the changes I think are necessary in the code, if no one 
objects.

> Unfortunately, the code in DatabaseUpdater.cpp is the only place I ever
> stored the database schema. eean asked me to create a diagram once

-> docs/database/amarokTables.svg

Bye
Tobias

-- 
...and justice for all!
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