Disallow finite partition bound following earlier UNBOUNDED column.

Amit Langote, per an observation by me.

Discussion: http://postgr.es/m/CA+TgmoYWnV2GMnYLG-Czsix-E1WGAbo4D+0tx7t9NdfYBDMFsA@mail.gmail.com

src/backend/parser/parse_utilcmd.c

@@ -3358,6 +3358,7 @@ transformPartitionBound(ParseState *pstate, Relation parent, Node *bound)
 		int			i,
 					j;
 		char	   *colname;
+		bool		seen_unbounded;
 
 		if (spec->strategy != PARTITION_STRATEGY_RANGE)
 			ereport(ERROR,
@@ -3376,6 +3377,39 @@ transformPartitionBound(ParseState *pstate, Relation parent, Node *bound)
 					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
 					 errmsg("TO must specify exactly one value per partitioning column")));
 
+		/*
+		 * Check that no finite value follows a UNBOUNDED literal in either of
+		 * lower and upper bound lists.
+		 */
+		seen_unbounded = false;
+		foreach(cell1, spec->lowerdatums)
+		{
+			PartitionRangeDatum *ldatum;
+
+			ldatum = (PartitionRangeDatum *) lfirst(cell1);
+			if (ldatum->infinite)
+				seen_unbounded = true;
+			else if (seen_unbounded)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("cannot specify finite value after UNBOUNDED"),
+						 parser_errposition(pstate, exprLocation((Node *) ldatum))));
+		}
+		seen_unbounded = false;
+		foreach(cell1, spec->upperdatums)
+		{
+			PartitionRangeDatum *rdatum;
+
+			rdatum = (PartitionRangeDatum *) lfirst(cell1);
+			if (rdatum->infinite)
+				seen_unbounded = true;
+			else if (seen_unbounded)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("cannot specify finite value after UNBOUNDED"),
+						 parser_errposition(pstate, exprLocation((Node *) rdatum))));
+		}
+
 		i = j = 0;
 		result_spec->lowerdatums = result_spec->upperdatums = NIL;
 		forboth(cell1, spec->lowerdatums, cell2, spec->upperdatums)

src/test/regress/expected/create_table.out

@@ -505,6 +505,13 @@ ERROR:  TO must specify exactly one value per partitioning column
 -- cannot specify null values in range bounds
 CREATE TABLE fail_part PARTITION OF range_parted FOR VALUES FROM (null) TO (unbounded);
 ERROR:  cannot specify NULL in range bound
+-- cannot specify finite values after UNBOUNDED has been specified
+CREATE TABLE range_parted_multicol (a int, b int, c int) PARTITION BY RANGE (a, b, c);
+CREATE TABLE fail_part PARTITION OF range_parted_multicol FOR VALUES FROM (1, UNBOUNDED, 1) TO (UNBOUNDED, 1, 1);
+ERROR:  cannot specify finite value after UNBOUNDED
+LINE 1: ...ge_parted_multicol FOR VALUES FROM (1, UNBOUNDED, 1) TO (UNB...
+                                                             ^
+DROP TABLE range_parted_multicol;
 -- check if compatible with the specified parent
 -- cannot create as partition of a non-partitioned table
 CREATE TABLE unparted (

src/test/regress/sql/create_table.sql

@@ -473,6 +473,11 @@ CREATE TABLE fail_part PARTITION OF range_parted FOR VALUES FROM ('a') TO ('z',
 -- cannot specify null values in range bounds
 CREATE TABLE fail_part PARTITION OF range_parted FOR VALUES FROM (null) TO (unbounded);
 
+-- cannot specify finite values after UNBOUNDED has been specified
+CREATE TABLE range_parted_multicol (a int, b int, c int) PARTITION BY RANGE (a, b, c);
+CREATE TABLE fail_part PARTITION OF range_parted_multicol FOR VALUES FROM (1, UNBOUNDED, 1) TO (UNBOUNDED, 1, 1);
+DROP TABLE range_parted_multicol;
+
 -- check if compatible with the specified parent
 
 -- cannot create as partition of a non-partitioned table