iphone - what's the likely max length of apple ios purchase receipt-data? -

Before testing the iOS AutoRevenue purchase, I have to prepare my server database. My question is simple. I just want to know that I What size should be made in the varchar field in your database.

I was using a varchar (4096) to store my base64 encoded receipts.

But to be honest, I could not find anything about the receipt length on the official document (or elsewhere). The only thing I found was that the receipt material / format is subject to change:

The content and format of the store receipt is subject to personal and changes. Your application should not attempt to parse the receipt data directly.

Then possibly going to text instead of varchar is actually the best option.