Is there a way to do symbolic links to the blob data when using Azure Storage to avoid duplicate blobs?

Question

I have a situation where a user is attaching files within an application, these files are then persisted to Azure Blob storage, there is a reasonable likelihood that there are going to be duplicates and I want to put in place a solution where duplicate blobs are avoided.

My first thought is to just name the blob as filename_hash but that only captures a subset of duplicates, then filesize_hash was then next thought.

In doing this though it seems like I am losing some of the flexibility of the blob storage to represent the position in a hierarchy of the file, see: Windows Azure: How to create sub directory in a blob container

So I was looking to see if there was a way to create a blob that referenced the blob data i.e. some for of symbolic link but couldn't find what I wanted.

Am I missing something or should I just go with filesize_hash method and store my hierarchy using an alternative method.

Answer 1

No, there's no symbolic links (source: http://social.msdn.microsoft.com/Forums/vi-VN/windowsazuredata/thread/6e5fa93a-0d09-44a8-82cf-a3403a695922).

A good solution depends on the anticipated size of the files and the number of duplicates. If there aren't going to be many duplicates, or the files are small, then it may actually be quicker and cheaper to live with it - $0.15 per gigabyte per month is not a great deal to pay, compared to the development cost! (That's the approach we're taking.)

If it was worthwhile to remove duplicates I'd use table storage to create some kind of redirection between the file name and the actual location of the data. I'd then do a client-side redirect to redirect the client's browser to download the proper version.

If you do this you'll want to preserve the file name (as that will be what's visible to the user) but you can call the "folder" location what you want.