| From: | Neil Conway <neilc(at)samurai(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | pgsql-patches <pgsql-patches(at)postgresql(dot)org> |
| Subject: | Re: Hash function for numeric (WIP) |
| Date: | 2007-05-07 01:23:05 |
| Message-ID: | 1178500985.18303.170.camel@goldbach |
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| Lists: | pgsql-patches |
On Thu, 2007-03-05 at 23:57 -0400, Tom Lane wrote:
> Hm, but apply hash_any() to the remaining digits? That might work, if
> you are careful about how you factor the weight into it (or just not try
> to use the weight in the hash).
Attached is a patch that implements this idea. Since leading or trailing
zeroes are far from the common case, I think we should still include the
weight in the hash when possible: the patch does so when it doesn't find
a leading zero in the Numeric. I did some testing by constructing an
in-memory Numeric with leading and trailing zeroes, and this approach
seems to work.
Unless you see anything else that needs fixing, I'll apply this patch to
HEAD in a day or two.
-Neil
| Attachment | Content-Type | Size |
|---|---|---|
| numeric_hash_func-6.patch | text/x-patch | 9.1 KB |
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