Add a hypopg_drop_table(oid) wrapper.

The underlying C function was already existing, I just forgot to add the
SQL wrapper.

The C function is modified to add an error if the function is called on
a non hypothetically partitioned table instead of silently doing
nothing, and add regression tests.

expected/hypo_table.out

@@ -1411,7 +1411,7 @@ SELECT * FROM hypopg_reset();
  
 (1 row)
 
-DROP TABLE part_multi CASCADE;
+DROP TABLE part_multi;
 CREATE TABLE part_multi(dpt smallint, dt date, val text) PARTITION BY LIST (dpt);
 SELECT * FROM hypopg_partition_table('hypo_part_multi', 'PARTITION BY LIST (dpt)');
  hypopg_partition_table 
@@ -1475,3 +1475,79 @@ EXPLAIN (COSTS OFF) SELECT * FROM hypo_part_multi;
    ->  Seq Scan on hypo_part_multi hypo_part_multi_2_q1
 (2 rows)
 
+-- removing hypothetical partitions
+-- ================================
+CREATE TABLE part_multi_1_q1_b PARTITION OF part_multi_1_q1 FOR VALUES FROM ($$2015-02-01$$) TO ($$2015-04-01$$);
+CREATE TABLE part_multi_1_q1_a PARTITION OF part_multi_1_q1 FOR VALUES FROM ($$2015-01-01$$) TO ($$2015-02-01$$);
+SELECT tablename FROM hypopg_add_partition('hypo_part_multi_1_q1_b', 'PARTITION OF hypo_part_multi_1_q1 FOR VALUES FROM ($$2015-02-01$$) TO ($$2015-04-01$$)');
+       tablename        
+------------------------
+ hypo_part_multi_1_q1_b
+(1 row)
+
+SELECT tablename FROM hypopg_add_partition('hypo_part_multi_1_q1_a', 'PARTITION OF hypo_part_multi_1_q1 FOR VALUES FROM ($$2015-01-01$$) TO ($$2015-02-01$$)');
+       tablename        
+------------------------
+ hypo_part_multi_1_q1_a
+(1 row)
+
+DROP TABLE part_multi_1_q1_a;
+SELECT hypopg_drop_table(relid) FROM hypopg_table() WHERE tablename = 'hypo_part_multi_1_q1_a';
+ hypopg_drop_table 
+-------------------
+ 
+(1 row)
+
+EXPLAIN (COSTS OFF) SELECT * FROM part_multi;
+             QUERY PLAN              
+-------------------------------------
+ Append
+   ->  Seq Scan on part_multi_1_q1_b
+   ->  Seq Scan on part_multi_2_q1
+(3 rows)
+
+EXPLAIN (COSTS OFF) SELECT * FROM hypo_part_multi;
+                        QUERY PLAN                        
+----------------------------------------------------------
+ Append
+   ->  Seq Scan on hypo_part_multi hypo_part_multi_1_q1_b
+   ->  Seq Scan on hypo_part_multi hypo_part_multi_2_q1
+(3 rows)
+
+DROP TABLE part_multi_1;
+SELECT hypopg_drop_table(relid) FROM hypopg_table() WHERE tablename = 'hypo_part_multi_1';
+ hypopg_drop_table 
+-------------------
+ 
+(1 row)
+
+EXPLAIN (COSTS OFF) SELECT * FROM part_multi;
+            QUERY PLAN             
+-----------------------------------
+ Append
+   ->  Seq Scan on part_multi_2_q1
+(2 rows)
+
+EXPLAIN (COSTS OFF) SELECT * FROM hypo_part_multi;
+                       QUERY PLAN                       
+--------------------------------------------------------
+ Append
+   ->  Seq Scan on hypo_part_multi hypo_part_multi_2_q1
+(2 rows)
+
+SELECT hypopg_drop_table(relid) FROM hypopg_table() WHERE tablename = 'hypo_part_multi';
+ hypopg_drop_table 
+-------------------
+ 
+(1 row)
+
+EXPLAIN (COSTS OFF) SELECT * FROM hypo_part_multi;
+         QUERY PLAN          
+-----------------------------
+ Seq Scan on hypo_part_multi
+(1 row)
+
+SELECT hypopg_drop_table(oid) FROM pg_class WHERE relname = 'pg_class';
+ERROR:  hypopg: Oid 1259 is not a hypothetically partitioned table
+SELECT hypopg_drop_table(1);
+ERROR:  hypopg: Oid 1 is not a hypothetically partitioned table

hypopg--2.0.0dev.sql

@@ -92,6 +92,11 @@ CREATE FUNCTION hypopg_reset_table()
     LANGUAGE C VOLATILE COST 100
 AS '$libdir/hypopg', 'hypopg_reset_table';
 
+CREATE FUNCTION hypopg_drop_table(IN relid oid)
+    RETURNS void
+    LANGUAGE C VOLATILE COST 100
+AS '$libdir/hypopg', 'hypopg_drop_table';
+
 CREATE FUNCTION hypopg_table(OUT relid oid, OUT tablename text,
     OUT parentid oid, OUT rootid oid,
     OUT partition_by_clause text, OUT partition_bounds text)

hypopg_table.c

@@ -3210,6 +3210,10 @@ HYPO_PARTITION_NOT_SUPPORTED();
 	/* Process any pending invalidation */
 	hypo_process_inval();
 
+	if (!hypo_table_oid_is_hypothetical(tableid))
+		elog(ERROR, "hypopg: Oid %d is not a hypothetically partitioned table",
+				tableid);
+
 	PG_RETURN_BOOL(hypo_table_remove(tableid, true));
 #endif
 }

test/sql/hypo_table.sql

@@ -266,7 +266,7 @@ EXPLAIN (COSTS OFF) WITH s AS (DELETE FROM foo USING part_range WHERE foo.id = p
 -- childless partitioning
 -- ======================
 SELECT * FROM hypopg_reset();
-DROP TABLE part_multi CASCADE;
+DROP TABLE part_multi;
 
 CREATE TABLE part_multi(dpt smallint, dt date, val text) PARTITION BY LIST (dpt);
 SELECT * FROM hypopg_partition_table('hypo_part_multi', 'PARTITION BY LIST (dpt)');
@@ -285,3 +285,29 @@ SELECT tablename FROM hypopg_add_partition('hypo_part_multi_1_q1', 'PARTITION OF
 
 EXPLAIN (COSTS OFF) SELECT * FROM part_multi;
 EXPLAIN (COSTS OFF) SELECT * FROM hypo_part_multi;
+
+-- removing hypothetical partitions
+-- ================================
+CREATE TABLE part_multi_1_q1_b PARTITION OF part_multi_1_q1 FOR VALUES FROM ($$2015-02-01$$) TO ($$2015-04-01$$);
+CREATE TABLE part_multi_1_q1_a PARTITION OF part_multi_1_q1 FOR VALUES FROM ($$2015-01-01$$) TO ($$2015-02-01$$);
+SELECT tablename FROM hypopg_add_partition('hypo_part_multi_1_q1_b', 'PARTITION OF hypo_part_multi_1_q1 FOR VALUES FROM ($$2015-02-01$$) TO ($$2015-04-01$$)');
+SELECT tablename FROM hypopg_add_partition('hypo_part_multi_1_q1_a', 'PARTITION OF hypo_part_multi_1_q1 FOR VALUES FROM ($$2015-01-01$$) TO ($$2015-02-01$$)');
+
+DROP TABLE part_multi_1_q1_a;
+SELECT hypopg_drop_table(relid) FROM hypopg_table() WHERE tablename = 'hypo_part_multi_1_q1_a';
+
+EXPLAIN (COSTS OFF) SELECT * FROM part_multi;
+EXPLAIN (COSTS OFF) SELECT * FROM hypo_part_multi;
+
+DROP TABLE part_multi_1;
+SELECT hypopg_drop_table(relid) FROM hypopg_table() WHERE tablename = 'hypo_part_multi_1';
+
+EXPLAIN (COSTS OFF) SELECT * FROM part_multi;
+EXPLAIN (COSTS OFF) SELECT * FROM hypo_part_multi;
+
+SELECT hypopg_drop_table(relid) FROM hypopg_table() WHERE tablename = 'hypo_part_multi';
+
+EXPLAIN (COSTS OFF) SELECT * FROM hypo_part_multi;
+
+SELECT hypopg_drop_table(oid) FROM pg_class WHERE relname = 'pg_class';
+SELECT hypopg_drop_table(1);