How to use an RSA public key as the primary key to a table in postgres

Question

I have a data set that needs to be looked up by RSA public keys. These keys are 392 text characters long.

What is the best way to make that a primary and/or unique key?

Should it be a BYTEA field?

Is it too long for a primary key? Should I store a shorter hashed version of it to index on and filter by first before checking for an exact match?

• András Váczi: If I were you, I would try and insert some sample data and test the performance hit of the long test PK on it. If (and only if) I saw problems when reaching the expected amount of data, would I venture into some more complicated designs. I wouldn't possibly choose bytea as the column type, and hashing might come handy.
• Hannah Vernon: Surely they are not really text? I imagine they are actually a long string of hexadecimal characters?
• Kyle: @MaxVernon - The public keys are actually a binary blob that has been base64 encoded
• Hannah Vernon: so perhaps converting them back to binary before storing them would be more efficient and result in a less-wide key?

Answer 1

I would say store them as bytea, but not for that reason. Simply because pg_crypto expects the keys as bytea. That establishes a convention. They likely have good reason for it: it seems intuitively faster.

Also there is no reason to store them as a PRIMARY KEY. You can sanely just store them in an indexed field.