Saving images: files or blobs?

I usually go with storing them as files, and store the path in the database. To me, it's a much easier and more natural approach than pushing them into the database as blobs.

One argument for storing them in the database: much easier to do full backups, but that depends on your needs. If you need to be able to easily take full snapshots of your database (including the images), then storing them as blobs in the database is probably the way to go. Otherwise you have to pair your database backup with a file backup, and somehow try to associate the two, so that if you have to do a restore, you know which pair to restore.

It depends on the size of the image.

Microsoft Research has an interesting document on the subject

I've tried to use the db (SQL Server and MySQL) to store medium (< 5mb) files, and what I got was tons of trouble.

1) Some DBs (SQL Server Express) have size limits;

2) Some DBs (MySQL) become mortally slow;

3) When you have to display a list of object, if you inadvertedly do SELECT * FROM table, tons of data will try to go up and down from the db, resulting in a deadly slow response or memory fail;

4) Some frontends (ruby ActiveRecord) have very big troubles handling blobs.

Just use files. Don't store them all in the same directory, use some technique to put them on several dirs (for instance, you could use last two chars of a GUID or last two digits of an int id) and then store the path on db.