My question is about displaying thumbnails and storage.
Let’s say I have a website where users can upload photos and view them in albums.
How are the photos usually stored in this scenario? Are the images themselves or are the file paths usually stored in the database?
If the photos are large and you want to display thumbnails, is it better to:
- save a copy of the image and a reduced size image, only displaying the larger if requested?
- use HTML to reduce the size?
It’s almost always a bad idea to store images in a database. BLOBs can really slow down a database something fierce. It also limits your ability to spread storage around different drives. When the files are separate, you can even have one or more separate image servers to reduce the load on the main dynamic server. My recommendations are:
In your database table, have columns for both the directory the image resides in and the image name. That way you are free to change where images are stored, round-robin drives, add more storage later and put new images in the new storage, or whatever you want. Storing the path and the filename in separate fields makes it trivial to move images from one directory to another.
You definitely want to generate thumbnail images to reduce your network bandwidth and make your application run faster. However, you can generate the thumbnails on demand, or when the system load is low. If you’re on Linux, ImageMagick is wonderful at automated batch resizing of images. It can even resize by a percentage instead of an absolute amount.