Harden tableam against nonexistant / wrong kind of AMs.

Previously it was allowed to set default_table_access_method to an
empty string. That makes sense for default_tablespace, where that was
copied from, as it signals falling back to the database's default
tablespace. As there is no equivalent for table AMs, forbid that.

Also make sure to throw a usable error when creating a table using an
index AM, by using get_am_type_oid() to implement get_table_am_oid()
instead of a separate copy. Previously we'd error out only later, in
GetTableAmRoutine().

Thirdly remove GetTableAmRoutineByAmId() - it was only used in an
earlier version of 8586bf7ed8.

Add tests for the above (some for index AMs as well).

1 files changed, 1 insertions, 0 deletions

diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 7f49625987a..4003080323d 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -156,6 +156,7 @@ extern Datum transformGenericOptions(Oid catalogId,
 extern ObjectAddress CreateAccessMethod(CreateAmStmt *stmt);
 extern void RemoveAccessMethodById(Oid amOid);
 extern Oid	get_index_am_oid(const char *amname, bool missing_ok);
+extern Oid	get_table_am_oid(const char *amname, bool missing_ok);
 extern Oid	get_am_oid(const char *amname, bool missing_ok);
 extern char *get_am_name(Oid amOid);