I'm writing an application that allows users to upload images onto the server. I expect about 20 images per day all jpeg and probably not edited/resized. (This is another question, how to resize the images on the server side before storing. Maybe someone can please drop a .NET resource for that in the comment or so). I wonder now what the best place for storing uploaded images is.
Store the images as a file in the file system and create a record in a table with the exact path to that image.
Or, store the image itself in a table using an "image" or "binary data" data type of the database server.
I see advantages and disadvantages in both. I like a) because I can easily relocate the files and just have to change the table entry. On the other hand I don't like storing business data on the web server and I don't really want to connect the web server to any other datasource that holds business data (for security reasons) I like b) because all the information is in one place and easily accessible by a query. On the other hand the database will get very big very soon. Outsourcing that data could be more difficult.
I generally store files on the file-system, since that's what its there for, though there are exceptions. For files, the file-system is the most flexible and performant solution (usually).
There are a few problems with storing files on a database - files are generally much larger than your average row - result-sets containing many large files will consume a lot of memory. Also, if you use a storage engine that employs table-locks for writes (ISAM for example), your files table might be locked often depending on the size / rate of files you are storing there.
Regarding security - I usually store the files in a directory that is outside of the document root (not accessible through an http request) and serve them through a script that checks for the proper authorization first.