I am developing a PHP web application. Looking for the efficient way of storing user uploaded images and display it on the web application. Please let me know your suggestions.
Expected number of images is 1 million.
My recommendation would be to use a combination of filesystem storage and database storage. Create a table that will contain your metadata about the image (user ID of uploader, etc) and include a field for the image's URL.
When someone uploads an image, move the file to a directory that is accessible from the web, and then store a record in the table you created which contains all the relevant data about the uploaded file, including the URL for the image. This way you can query the database for information about the image but you don't have to store the file's contents in the database.