Ask HN: SQL AND Flat File?

I was just thinking, how quick it would be to store the actual data of an application in a flat file.

Now, you can't just go storing everything in a flat file... sometimes sorts and searches are required, and to go through directories and files recursively could be a pain.

Now, imagine, you stored all your searchable data in a database, and had a pointer field, that pointed to a data file?

This would be very specific per app, however- so long as all my searchable data is stored in the database, why should I store the actual data in a database?

(Locking aside) it would be faster, I am sure... but how much, worth doing it?