Re: [HACKERS] Hash Functions

On Sat, May 13, 2017 at 7:08 PM, Andres Freund <andres@anarazel.de> wrote:
> I seriously doubt that's true.  A lot of more complex types have
> internal alignment padding and such.

True, but I believe we require those padding bytes to be zero.  If we
didn't, then hstore_hash would be broken already.

> Consider e.g. something like
> jsonb, hstore, or postgis types - you *can* convert them to something
> that's unambiguous, but it's going to be fairly expensive.

I'm fuzzy on what you think we'd need to do.

> Essentially
> you'd have to something like calling the output function, and then
> hashing the result of that.

I really don't see why we'd have to go to nearly that length.

-- 
Robert Haas
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