From: | Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com> |
---|---|
To: | pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | simplehash: tb->sizemask = 0 |
Date: | 2017-11-27 20:34:52 |
Message-ID: | ad325190-4957-200b-7f1c-f2b936bfe74d@2ndquadrant.com |
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Lists: | pgsql-hackers |
Hi,
I'm a bit puzzled by this code in SH_COMPUTE_PARAMETERS:
if (tb->size == SH_MAX_SIZE)
tb->sizemask = 0;
else
tb->sizemask = tb->size - 1;
Doesn't that mean that with SH_MAX_SIZE we end up with sizemask being 0
(i.e. no bits set)? At least that's what I get from
printf("%#x\n", (unsigned int)0);
That would mean SH_INITIAL_BUCKET/SH_NEXT/SH_PREV can only ever return
bucket 0, no?
I don't think we're building hash tables with 2^32 buckets, though.
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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