Add function to detach tablespaces from hypertables

Tablespaces can now be detached from hypertables using
`tablespace_detach()`. This function can either detach
a tablespace from all tables or only a specific table.

Having the ability to detach tablespace allows more
advanced storage management, for instance, one can detach
tablespaces that are running low on diskspace while attaching
new ones to replace the old ones.

sql/ddl_api.sql

@@ -303,3 +303,17 @@ CREATE OR REPLACE FUNCTION attach_tablespace(tablespace NAME, hypertable REGCLAS
 $BODY$
     SELECT * FROM _timescaledb_internal.attach_tablespace(tablespace, hypertable);
 $BODY$;
+
+-- Detach the given tablespace from a hypertable
+CREATE OR REPLACE FUNCTION detach_tablespace(tablespace NAME, hypertable REGCLASS = NULL)
+       RETURNS INTEGER LANGUAGE SQL AS
+$BODY$
+    SELECT * FROM _timescaledb_internal.detach_tablespace(tablespace, hypertable);
+$BODY$;
+
+-- Detach all tablespaces from the a hypertable
+CREATE OR REPLACE FUNCTION detach_tablespaces(hypertable REGCLASS)
+       RETURNS INTEGER LANGUAGE SQL AS
+$BODY$
+    SELECT * FROM _timescaledb_internal.detach_tablespaces(hypertable);
+$BODY$;

sql/ddl_internal.sql

@@ -65,7 +65,7 @@ BEGIN
     -- Create the schema for the hypertable data if needed
     PERFORM _timescaledb_internal.create_hypertable_schema(associated_schema_name);
 
-    id :=  nextval(pg_get_serial_sequence('_timescaledb_catalog.hypertable','id'));
+    id := nextval(pg_get_serial_sequence('_timescaledb_catalog.hypertable','id'));
 
     IF associated_table_prefix IS NULL THEN
         associated_table_prefix = format('_hyper_%s', id);
@@ -621,6 +621,12 @@ $BODY$;
 CREATE OR REPLACE FUNCTION _timescaledb_internal.attach_tablespace(tablespace NAME, hypertable REGCLASS) RETURNS VOID
 AS '$libdir/timescaledb', 'tablespace_attach' LANGUAGE C VOLATILE;
 
+CREATE OR REPLACE FUNCTION _timescaledb_internal.detach_tablespace(tablespace NAME, hypertable REGCLASS) RETURNS INTEGER
+AS '$libdir/timescaledb', 'tablespace_detach' LANGUAGE C VOLATILE;
+
+CREATE OR REPLACE FUNCTION _timescaledb_internal.detach_tablespaces(hypertable REGCLASS) RETURNS INTEGER
+AS '$libdir/timescaledb', 'tablespace_detach_all_from_hypertable' LANGUAGE C VOLATILE;
+
 --documentation of these function located in chunk_index.h
 CREATE OR REPLACE FUNCTION _timescaledb_internal.chunk_index_clone(chunk_index_oid OID) RETURNS OID
 AS '$libdir/timescaledb', 'chunk_index_clone' LANGUAGE C VOLATILE STRICT;

sql/updates/pre-0.6.1--0.7.0.sql

@@ -35,6 +35,3 @@ DROP FUNCTION create_hypertable(regclass,name,name,integer,name,name,anyelement,
 DROP FUNCTION add_dimension(regclass,name,integer,bigint);
 DROP FUNCTION _timescaledb_internal.create_hypertable_row(regclass,name,name,name,name,integer,name,name,bigint,name);
 DROP FUNCTION _timescaledb_internal.add_dimension(regclass,_timescaledb_catalog.hypertable,name,integer,bigint,boolean);
-
--- Tablespace functions
-DROP FUNCTION _timescaledb_internal.attach_tablespace(integer, name);

src/catalog.c

@@ -467,6 +467,11 @@ catalog_delete(Relation rel, HeapTuple tuple)
 	catalog_delete_tid(rel, &tuple->t_self);
 }
 
+void
+catalog_delete_only(Relation rel, HeapTuple tuple)
+{
+	CatalogTupleDelete(rel, &tuple->t_self);
+}
 
 /*
  * Invalidate TimescaleDB catalog caches.
@@ -510,6 +515,7 @@ catalog_invalidate_cache(Oid catalog_relid, CmdType operation)
 			break;
 		case HYPERTABLE:
 		case DIMENSION:
+		case TABLESPACE:
 			relid = catalog_get_cache_proxy_id(catalog, CACHE_TYPE_HYPERTABLE);
 			CacheInvalidateRelcacheByRelid(relid);
 			break;

src/catalog.h

@@ -519,4 +519,7 @@ void		catalog_delete_tid(Relation rel, ItemPointer tid);
 void		catalog_delete(Relation rel, HeapTuple tuple);
 void		catalog_invalidate_cache(Oid catalog_relid, CmdType operation);
 
+/* Delete only: do not increment command counter or invalidate caches */
+void		catalog_delete_only(Relation rel, HeapTuple tuple);
+
 #endif   /* TIMESCALEDB_CATALOG_H */

src/errors.h

@@ -28,6 +28,7 @@
 #define ERRCODE_IO_NODE_EXISTS MAKE_SQLSTATE('I','O','1','2','0')
 #define ERRCODE_IO_USER_EXISTS MAKE_SQLSTATE('I','O','1','3','0')
 #define ERRCODE_IO_TABLESPACE_ALREADY_ATTACHED MAKE_SQLSTATE('I','O','1','4','0')
+#define ERRCODE_IO_TABLESPACE_NOT_ATTACHED MAKE_SQLSTATE('I','O','1','5','0')
 
 /*
 --IO500 - GROUP: internal error

src/hypertable.c

@@ -1,10 +1,13 @@
 #include <postgres.h>
 #include <access/htup_details.h>
 #include <utils/lsyscache.h>
+#include <utils/syscache.h>
 #include <utils/memutils.h>
 #include <utils/builtins.h>
 #include <nodes/memnodes.h>
 #include <catalog/namespace.h>
+#include <commands/tablespace.h>
+#include <miscadmin.h>
 
 #include "hypertable.h"
 #include "dimension.h"
@@ -16,6 +19,48 @@
 #include "scanner.h"
 #include "catalog.h"
 
+static Oid
+rel_get_owner(Oid relid)
+{
+	HeapTuple	tuple;
+	Oid			ownerid;
+
+	tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
+
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_TABLE),
+				 errmsg("relation with OID %u does not exist", relid)));
+
+	ownerid = ((Form_pg_class) GETSTRUCT(tuple))->relowner;
+
+	ReleaseSysCache(tuple);
+
+	return ownerid;
+}
+
+bool
+hypertable_has_privs_of(Oid hypertable_oid, Oid userid)
+{
+	return has_privs_of_role(userid, rel_get_owner(hypertable_oid));
+}
+
+Oid
+hypertable_permissions_check(Oid hypertable_oid, Oid userid)
+{
+	Oid			ownerid = rel_get_owner(hypertable_oid);
+
+	if (!has_privs_of_role(userid, ownerid))
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("User \"%s\" lacks permissions on table \"%s\"",
+						GetUserNameFromId(userid, true),
+						get_rel_name(hypertable_oid))));
+
+	return ownerid;
+}
+
+
 Hypertable *
 hypertable_from_tuple(HeapTuple tuple)
 {
@@ -230,7 +275,31 @@ hypertable_has_tablespace(Hypertable *ht, Oid tspc_oid)
 Tablespace *
 hypertable_add_tablespace(Hypertable *ht, int32 tspc_id, Oid tspc_oid)
 {
-	return tablespaces_add(ht->tablespaces, tspc_id, tspc_oid);
+	FormData_tablespace form = {
+		.id = tspc_id,
+		.hypertable_id = ht->fd.id,
+	};
+
+	namestrcpy(&form.tablespace_name, get_tablespace_name(tspc_oid));
+	return tablespaces_add(ht->tablespaces, &form, tspc_oid);
+}
+
+bool
+hypertable_delete_tablespace(Hypertable *ht, Oid tspc_oid)
+{
+	if (NULL == ht->tablespaces)
+		return false;
+
+	return tablespaces_delete(ht->tablespaces, tspc_oid);
+}
+
+int
+hypertable_delete_all_tablespaces(Hypertable *ht)
+{
+	if (NULL == ht->tablespaces)
+		return 0;
+
+	return tablespaces_clear(ht->tablespaces);
 }
 
 static inline Oid

src/hypertable.h

@@ -21,6 +21,8 @@ typedef struct Hypertable
 	Tablespaces *tablespaces;
 } Hypertable;
 
+extern bool hypertable_has_privs_of(Oid hypertable_oid, Oid userid);
+extern Oid	hypertable_permissions_check(Oid hypertable_oid, Oid userid);
 extern Hypertable *hypertable_from_tuple(HeapTuple tuple);
 extern int	hypertable_set_name(Hypertable *ht, const char *newname);
 extern int	hypertable_set_schema(Hypertable *ht, const char *newname);
@@ -30,5 +32,7 @@ extern Oid	hypertable_relid(RangeVar *rv);
 extern bool is_hypertable(Oid relid);
 extern bool hypertable_has_tablespace(Hypertable *ht, Oid tspc_oid);
 extern Tablespace *hypertable_add_tablespace(Hypertable *ht, int32 tspc_id, Oid tspc_oid);
+extern bool hypertable_delete_tablespace(Hypertable *ht, Oid tspc_id);
+extern int	hypertable_delete_all_tablespaces(Hypertable *ht);
 
 #endif   /* TIMESCALEDB_HYPERTABLE_H */

src/process_utility.c

@@ -1594,7 +1594,7 @@ timescaledb_ddl_command_start(
 							  ProcessUtilityContext context,
 							  ParamListInfo params,
 #if PG10
-							  QueryEnvironment * queryEnv,
+							  QueryEnvironment *queryEnv,
 #endif
 							  DestReceiver *dest,
 							  char *completion_tag)