Remove 'func_tlist' from Func expression nodes, likewise 'param_tlist'

from Param nodes, per discussion a few days ago on pghackers.  Add new
expression node type FieldSelect that implements the functionality where
it's actually needed.  Clean up some other unused fields in Func nodes
as well.
NOTE: initdb forced due to change in stored expression trees for rules.

1 files changed, 31 insertions, 17 deletions

diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 47de5779ae5..1ad9a3d082a 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: primnodes.h,v 1.45 2000/07/22 04:22:47 tgl Exp $
+ * $Id: primnodes.h,v 1.46 2000/08/08 15:42:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -160,10 +160,9 @@ typedef struct Var
 /* ----------------
  * Oper
  *		opno			- PG_OPERATOR OID of the operator
- *		opid			- PG_PROC OID for the operator
+ *		opid			- PG_PROC OID for the operator's underlying function
  *		opresulttype	- PG_TYPE OID of the operator's return value
- *		opsize			- size of return result (cached by executor)
- *		op_fcache		- XXX comment me.
+ *		op_fcache		- runtime state while running the function
  *
  * ----
  * NOTE: in the good old days 'opno' used to be both (or either, or
@@ -175,6 +174,10 @@ typedef struct Var
  * (i.e. a mess) some comments were referring to 'opno' using the name
  * 'opid'. Anyway, now we have two separate fields, and of course that
  * immediately removes all bugs from the code...		[ sp :-) ].
+ *
+ * Note also that opid is not necessarily filled in immediately on creation
+ * of the node.  The planner makes sure it is valid before passing the node
+ * tree to the executor, but during parsing/planning opid is typically 0.
  * ----------------
  */
 typedef struct Oper
@@ -183,7 +186,6 @@ typedef struct Oper
 	Oid			opno;
 	Oid			opid;
 	Oid			opresulttype;
-	int			opsize;
 	FunctionCachePtr op_fcache;
 } Oper;
 
@@ -240,7 +242,6 @@ typedef struct Const
  *		paramid - numeric identifier for literal-constant parameters ("$1")
  *		paramname - attribute name for tuple-substitution parameters ("$.foo")
  *		paramtype - PG_TYPE OID of the parameter's value
- *		param_tlist - allows for projection in a param node.
  * ----------------
  */
 typedef struct Param
@@ -250,23 +251,17 @@ typedef struct Param
 	AttrNumber	paramid;
 	char	   *paramname;
 	Oid			paramtype;
-	List	   *param_tlist;
 } Param;
 
 
 /* ----------------
  * Func
- *		funcid			- PG_FUNCTION OID of the function
+ *		funcid			- PG_PROC OID of the function
  *		functype		- PG_TYPE OID of the function's return value
- *		funcisindex		- the function can be evaluated by scanning an index
- *						  (set during query optimization)
- *		funcsize		- size of return result (cached by executor)
  *		func_fcache		- runtime state while running this function.  Where
  *						  we are in the execution of the function if it
  *						  returns more than one value, etc.
  *						  See utils/fcache.h
- *		func_tlist		- projection of functions returning tuples
- *		func_planlist	- result of planning this func, if it's a PQ func
  * ----------------
  */
 typedef struct Func
@@ -274,11 +269,7 @@ typedef struct Func
 	NodeTag		type;
 	Oid			funcid;
 	Oid			functype;
-	bool		funcisindex;
-	int			funcsize;
 	FunctionCachePtr func_fcache;
-	List	   *func_tlist;
-	List	   *func_planlist;
 } Func;
 
 /* ----------------
@@ -440,6 +431,29 @@ typedef struct ArrayRef
 } ArrayRef;
 
 /* ----------------
+ * FieldSelect
+ *		arg				- input expression
+ *		fieldnum		- attribute number of field to extract
+ *		resulttype		- type of the field (result type of this node)
+ *		resulttypmod	- output typmod (usually -1)
+ *
+ * FieldSelect represents the operation of extracting one field from a tuple
+ * value.  At runtime, the input expression is expected to yield a Datum
+ * that contains a pointer-to-TupleTableSlot.  The specified field number
+ * is extracted and returned as a Datum.
+ * ----------------
+ */
+
+typedef struct FieldSelect
+{
+	NodeTag		type;
+	Node	   *arg;
+	AttrNumber	fieldnum;
+	Oid			resulttype;
+	int32		resulttypmod;
+} FieldSelect;
+
+/* ----------------
  * RelabelType
  *		arg				- input expression
  *		resulttype		- output type of coercion expression