On Sat, Sep 6, 2014 at 3:01 PM, Peter Geoghegan <p...@heroku.com> wrote:
> I attach another amendment/delta patch
Attached is another amendment to the patch set. With the recent
addition of abbreviation support on 32-bit platforms, we should just
hash the Datum representation as a uint32 on SIZEOF_DATUM != 8
platforms.
--
Peter Geoghegan
From 180ad839d8f049d83a89b42a1d85c7c99a7929f0 Mon Sep 17 00:00:00 2001
From: Peter Geoghegan <p...@heroku.com>
Date: Sat, 6 Sep 2014 21:39:16 -0700
Subject: [PATCH 9/9] On SIZEOF_DATUM != 4 platforms, call hash_uint32()
directly
In passing, remove some dead code within bttext_abbrev_abort().
---
src/backend/utils/adt/varlena.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index db4eae1..23944f2 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -2068,9 +2068,7 @@ bttext_abbrev_convert(Datum original, SortSupport ssup)
char *pres;
int len;
Size bsize;
- uint32 lohalf,
- hihalf,
- hash;
+ uint32 hash;
/*
* Abbreviated key representation is a pass-by-value Datum that is treated
@@ -2143,9 +2141,18 @@ retry:
memcpy(pres, tss->buf2, Min(sizeof(Datum), bsize));
/* Hash abbreviated key */
- lohalf = (uint32) res;
- hihalf = (uint32) (res >> 32);
- hash = hash_uint32(lohalf ^ hihalf);
+#if SIZEOF_DATUM == 8
+ {
+ uint32 lohalf,
+ hihalf;
+
+ lohalf = (uint32) res;
+ hihalf = (uint32) (res >> 32);
+ hash = hash_uint32(lohalf ^ hihalf);
+ }
+#else /* SIZEOF_DATUM != 8 */
+ hash = hash_uint32((uint32) res);
+#endif
addHyperLogLog(&tss->abbr_card, hash);
@@ -2168,8 +2175,7 @@ bttext_abbrev_abort(int memtupcount, double rowhint, SortSupport ssup)
{
TextSortSupport *tss = (TextSortSupport *) ssup->ssup_extra;
double abbrev_distinct,
- key_distinct,
- norm_key_card;
+ key_distinct;
Assert(ssup->abbrev_state == ABBREVIATED_KEYS_YES);
@@ -2289,12 +2295,6 @@ bttext_abbrev_abort(int memtupcount, double rowhint, SortSupport ssup)
return false;
/*
- * Normalized cardinality is proportion of distinct original, authoritative
- * keys
- */
- norm_key_card = key_distinct / (double) memtupcount;
-
- /*
* Abort abbreviation strategy.
*
* The worst case, where all abbreviated keys are identical while all
--
1.9.1
--
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