[KPhotoAlbum] Search performance

[Tobias Leupold]

> But I still think that the index.xml format has good properties (resistant
> against file corruption, easy/robust versioning, readable and writable "by
> hand"). Also, many people use kphotoalbum on different machines in different
> versions - with the XML format, you can easily pull that off as long as you
> take some care.

I must say that the XML database format was one reason for me to use KPA at 
all back then. I thought I'll spend a lot of time with tagging and a lot of 
energy will flow into this database. And if the KPA thing ends up sucking one 
day, I will still have that database that I can even read "by hand" with a 
normal text editor. And that's why I thought "no matter what happens, my data 
is safe and mine after all".

I don't know if other users have/had the same thought. But I think this 
"special" approach (I don't think it's really common for that task) to save 
the data is a good thing.

Surely, one can optimize. A in-memory SQLite datase for fast search queries is 
a nice idea for sure. But I would really stick to the XML file as the on-disk 
storage format.

Just my thoughts ...