Remove sql_inheritance GUC.

This backward-compatibility GUC is long overdue for removal.

Discussion: http://postgr.es/m/CA+TgmoYe+EG7LdYX6pkcNxr4ygkP4+A=jm9o-CPXyOvRiCNwaQ@mail.gmail.com

src/backend/parser/analyze.c

@@ -380,7 +380,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
 
 	/* set up range table with just the result rel */
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
-								  interpretInhOption(stmt->relation->inhOpt),
+								  (stmt->relation->inhOpt == INH_YES),
 										 true,
 										 ACL_DELETE);
 
@@ -2177,7 +2177,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
 	}
 
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
-								  interpretInhOption(stmt->relation->inhOpt),
+								  (stmt->relation->inhOpt == INH_YES),
 										 true,
 										 ACL_UPDATE);
 

src/backend/parser/gram.y

@@ -28,12 +28,11 @@
  *	  current transaction and are just parsing commands to find the next
  *	  ROLLBACK or COMMIT.  If you make use of SET variables, then you
  *	  will do the wrong thing in multi-query strings like this:
- *			SET SQL_inheritance TO off; SELECT * FROM foo;
+ *			SET constraint_exclusion TO off; SELECT * FROM foo;
  *	  because the entire string is parsed by gram.y before the SET gets
  *	  executed.  Anything that depends on the database or changeable state
  *	  should be handled during parse analysis so that it happens at the
- *	  right time not the wrong time.  The handling of SQL_inheritance is
- *	  a good example.
+ *	  right time not the wrong time.
  *
  * WARNINGS
  *	  If you use a list, make sure the datum is a node so that the printing
@@ -11249,9 +11248,9 @@ join_qual:	USING '(' name_list ')'					{ $$ = (Node *) $3; }
 relation_expr:
 			qualified_name
 				{
-					/* default inheritance */
+					/* inheritance query, implicitly */
 					$$ = $1;
-					$$->inhOpt = INH_DEFAULT;
+					$$->inhOpt = INH_YES;
 					$$->alias = NULL;
 				}
 			| qualified_name '*'

src/backend/parser/parse_clause.c

@@ -228,30 +228,6 @@ setTargetTable(ParseState *pstate, RangeVar *relation,
 	return rtindex;
 }
 
-/*
- * Simplify InhOption (yes/no/default) into boolean yes/no.
- *
- * The reason we do things this way is that we don't want to examine the
- * SQL_inheritance option flag until parse_analyze() is run.    Otherwise,
- * we'd do the wrong thing with query strings that intermix SET commands
- * with queries.
- */
-bool
-interpretInhOption(InhOption inhOpt)
-{
-	switch (inhOpt)
-	{
-		case INH_NO:
-			return false;
-		case INH_YES:
-			return true;
-		case INH_DEFAULT:
-			return SQL_inheritance;
-	}
-	elog(ERROR, "bogus InhOption value: %d", inhOpt);
-	return false;				/* keep compiler quiet */
-}
-
 /*
  * Given a relation-options list (of DefElems), return true iff the specified
  * table/result set should be created with OIDs. This needs to be done after
@@ -437,7 +413,7 @@ transformTableEntry(ParseState *pstate, RangeVar *r)
 
 	/* We need only build a range table entry */
 	rte = addRangeTableEntry(pstate, r, r->alias,
-							 interpretInhOption(r->inhOpt), true);
+							 (r->inhOpt == INH_YES), true);
 
 	return rte;
 }