Re: Hash support for arrays

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Greg Stark <gsstark(at)mit(dot)edu>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Hash support for arrays
Date: 2010-10-30 20:48:17
Message-ID: 23126.1288471697@sss.pgh.pa.us
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Greg Stark <gsstark(at)mit(dot)edu> writes:
> On Sat, Oct 30, 2010 at 9:21 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Thoughts? In particular, is anyone aware of a better method
>> for combining the element hash values?

> The obvious thing to do seems like it would be to feed the individual
> values back into the regular hash function.

Hmm, you mean use hash_any on the sequence of hash values? Interesting
idea; but hash_any doesn't look very amenable to being invoked
incrementally, and I don't think I want to construct a temp array with
enough space for the hashes of all the items in the input array ...

regards, tom lane

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