Change bms_add_range to be a no-op for empty ranges

In commit 84940644de93, bms_add_range was added with an API to fail with
an error if an empty range was specified.  This seems arbitrary and
unhelpful, so turn that case into a no-op instead.  Callers that require
further verification on the arguments or result can apply them by
themselves.

This fixes the bug that partition pruning throws an API error for a case
involving the default partition of a default partition, as in the
included test case.

Reported-by: Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>
Diagnosed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/16590.1532622503@sss.pgh.pa.us

diff --git a/src/backend/nodes/bitmapset.c b/src/backend/nodes/bitmapset.c
index 9bf9a29d6b18730485fd57d1c12120831733af37..6208f4ed936c129efec9723d0ba691ed9cdfaa97 100644 (file)
--- a/src/backend/nodes/bitmapset.c
+++ b/src/backend/nodes/bitmapset.c
@@ -867,6 +867,10 @@ bms_add_range(Bitmapset *a, int lower, int upper)
                                ushiftbits,
                                wordnum;
 
+       /* do nothing if nothing is called for, without further checking */
+       if (upper < lower)
+               return a;
+
        if (lower < 0 || upper < 0)
                elog(ERROR, "negative bitmapset member not allowed");
        if (lower > upper)
@@ -878,13 +882,12 @@ bms_add_range(Bitmapset *a, int lower, int upper)
                a = (Bitmapset *) palloc0(BITMAPSET_SIZE(uwordnum + 1));
                a->nwords = uwordnum + 1;
        }
-
-       /* ensure we have enough words to store the upper bit */
        else if (uwordnum >= a->nwords)
        {
                int                     oldnwords = a->nwords;
                int                     i;
 
+               /* ensure we have enough words to store the upper bit */
                a = (Bitmapset *) repalloc(a, BITMAPSET_SIZE(uwordnum + 1));
                a->nwords = uwordnum + 1;
                /* zero out the enlarged portion */

diff --git a/src/test/regress/expected/partition_prune.out b/src/test/regress/expected/partition_prune.out
index 38bd179c22245188e0fd3afb453923b2a9c88fff..3fef4921aac74f74cc0917f5198954b00bf20002 100644 (file)
--- a/src/test/regress/expected/partition_prune.out
+++ b/src/test/regress/expected/partition_prune.out
@@ -1180,6 +1180,21 @@ explain (costs off) select * from coercepart where a !~ all ('{ab,bc}');
 (7 rows)
 
 drop table coercepart;
+CREATE TABLE part (a INT, b INT) PARTITION BY LIST (a);
+CREATE TABLE part_p1 PARTITION OF part FOR VALUES IN (-2,-1,0,1,2);
+CREATE TABLE part_p2 PARTITION OF part DEFAULT PARTITION BY RANGE(a);
+CREATE TABLE part_p2_p1 PARTITION OF part_p2 DEFAULT;
+INSERT INTO part VALUES (-1,-1), (1,1), (2,NULL), (NULL,-2),(NULL,NULL);
+EXPLAIN (COSTS OFF) SELECT tableoid::regclass as part, a, b FROM part WHERE a IS NULL ORDER BY 1, 2, 3;
+                                QUERY PLAN                                 
+---------------------------------------------------------------------------
+ Sort
+   Sort Key: ((part_p2_p1.tableoid)::regclass), part_p2_p1.a, part_p2_p1.b
+   ->  Append
+         ->  Seq Scan on part_p2_p1
+               Filter: (a IS NULL)
+(5 rows)
+
 --
 -- some more cases
 --

diff --git a/src/test/regress/sql/partition_prune.sql b/src/test/regress/sql/partition_prune.sql
index e5e7789fc5b252b8d9e44dbf15d6b204fa67ca5c..4b198b1a1d7c14f78dcdb524a3251406a0db770b 100644 (file)
--- a/src/test/regress/sql/partition_prune.sql
+++ b/src/test/regress/sql/partition_prune.sql
@@ -173,6 +173,13 @@ explain (costs off) select * from coercepart where a !~ all ('{ab,bc}');
 
 drop table coercepart;
 
+CREATE TABLE part (a INT, b INT) PARTITION BY LIST (a);
+CREATE TABLE part_p1 PARTITION OF part FOR VALUES IN (-2,-1,0,1,2);
+CREATE TABLE part_p2 PARTITION OF part DEFAULT PARTITION BY RANGE(a);
+CREATE TABLE part_p2_p1 PARTITION OF part_p2 DEFAULT;
+INSERT INTO part VALUES (-1,-1), (1,1), (2,NULL), (NULL,-2),(NULL,NULL);
+EXPLAIN (COSTS OFF) SELECT tableoid::regclass as part, a, b FROM part WHERE a IS NULL ORDER BY 1, 2, 3;
+
 --
 -- some more cases
 --