Remove unused constisset and constiscast fields of Const nodes. Clean

up code and documentation associated with Param nodes.

4 files changed, 67 insertions, 75 deletions

diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index c9781b7255f..6ee39b98182 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: execnodes.h,v 1.79 2002/11/22 22:10:01 tgl Exp $
+ * $Id: execnodes.h,v 1.80 2002/11/25 21:29:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -281,14 +281,15 @@ typedef struct ResultRelInfo
  *
  *		direction						direction of the scan
  *
+ *		snapshot						time qual to use
+ *
  *		range_table						array of scan relation information
  *
  *		result_relation information		for insert/update/delete queries
  *
  *		into_relation_descriptor		relation being retrieved "into"
  *
- *		param_list_info					information needed to transform
- *										Param nodes into Const nodes
+ *		param_list_info					information about Param values
  *
  *		tupleTable						this is a pointer to an array
  *										of pointers to tuples used by
@@ -307,8 +308,8 @@ typedef struct EState
 												 * elt */
 	JunkFilter *es_junkFilter;	/* currently active junk filter */
 	Relation	es_into_relation_descriptor;
-	ParamListInfo es_param_list_info;
-	ParamExecData *es_param_exec_vals;	/* this is for subselects */
+	ParamListInfo es_param_list_info;	/* values of external params */
+	ParamExecData *es_param_exec_vals;	/* values of internal params */
 	TupleTable	es_tupleTable;
 	uint32		es_processed;	/* # of tuples processed */
 	Oid			es_lastoid;		/* last oid processed (by INSERT) */
@@ -322,6 +323,7 @@ typedef struct EState
 	 * needed.
 	 */
 	ExprContext *es_per_tuple_exprcontext;
+
 	/* Below is to re-evaluate plan qual in READ COMMITTED mode */
 	struct Plan *es_origPlan;
 	Pointer		es_evalPlanQual;
diff --git a/src/include/nodes/makefuncs.h b/src/include/nodes/makefuncs.h
index e7c9c29413c..68f0dcda49a 100644
--- a/src/include/nodes/makefuncs.h
+++ b/src/include/nodes/makefuncs.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: makefuncs.h,v 1.41 2002/09/18 21:35:24 tgl Exp $
+ * $Id: makefuncs.h,v 1.42 2002/11/25 21:29:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -45,9 +45,7 @@ extern Const *makeConst(Oid consttype,
 		  int constlen,
 		  Datum constvalue,
 		  bool constisnull,
-		  bool constbyval,
-		  bool constisset,
-		  bool constiscast);
+		  bool constbyval);
 
 extern Const *makeNullConst(Oid consttype);
 
diff --git a/src/include/nodes/params.h b/src/include/nodes/params.h
index 1aa17964d65..ef0e0682be6 100644
--- a/src/include/nodes/params.h
+++ b/src/include/nodes/params.h
@@ -1,13 +1,13 @@
 /*-------------------------------------------------------------------------
  *
  * params.h
- *	  Declarations/definitions of stuff needed to handle parameterized plans.
+ *	  Declarations of stuff needed to handle parameterized plans.
  *
  *
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: params.h,v 1.17 2002/06/20 20:29:51 momjian Exp $
+ * $Id: params.h,v 1.18 2002/11/25 21:29:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -16,66 +16,55 @@
 
 #include "access/attnum.h"
 
-/* ----------------------------------------------------------------
- *
+
+/* ----------------
  * The following are the possible values for the 'paramkind'
  * field of a Param node.
  *
  * PARAM_NAMED: The parameter has a name, i.e. something
  *				like `$.salary' or `$.foobar'.
- *				In this case field `paramname' must be a valid Name.
- *				and field `paramid' must be == 0.
+ *				In this case field `paramname' must be a valid name.
  *
  * PARAM_NUM:	The parameter has only a numeric identifier,
  *				i.e. something like `$1', `$2' etc.
- *				The number is contained in the `parmid' field.
+ *				The number is contained in the `paramid' field.
  *
- * PARAM_NEW:	Used in PRS2 rule, similar to PARAM_NAMED.
- *				The `paramname' & `paramid' refer to the "NEW" tuple
- *				`paramname' is the attribute name and `paramid' its
- *				attribute number.
+ * PARAM_EXEC:	The parameter is an internal executor parameter.
+ *				It has a number contained in the `paramid' field.
  *
- * PARAM_OLD:	Same as PARAM_NEW, but in this case we refer to
- *				the "OLD" tuple.
- *
- * PARAM_EXEC:	Evaluated by executor. Used for subselect...
+ * PARAM_INVALID should never appear in a Param node; it's used to mark
+ * the end of a ParamListInfo array.
  *
+ * NOTE: As of PostgreSQL 7.3, named parameters aren't actually used and
+ * so the code that handles PARAM_NAMED cases is dead code.  We leave it
+ * in place since it might be resurrected someday.
+ * ----------------
  */
 
 #define PARAM_NAMED		11
 #define PARAM_NUM		12
-#define PARAM_NEW		13
-#define PARAM_OLD		14
 #define PARAM_EXEC		15
 #define PARAM_INVALID	100
 
 
-/* ----------------------------------------------------------------
+/* ----------------
  *	  ParamListInfo
  *
- *	  Information needed in order for the executor to handle
- *	  parameterized plans (you know,  $.salary, $.name etc. stuff...).
- *
- *	  ParamListInfoData contains information needed when substituting a
- *	  Param node with a Const node.
+ *	  ParamListInfo entries are used to pass parameters into the executor
+ *	  for parameterized plans.  Each entry in the array defines the value
+ *	  to be substituted for a PARAM_NAMED or PARAM_NUM parameter.
  *
- *		kind   : the kind of parameter.
- *		name   : the parameter name (valid if kind == PARAM_NAMED,
- *				 PARAM_NEW or PARAM_OLD)
+ *		kind   : the kind of parameter (PARAM_NAMED or PARAM_NUM)
+ *		name   : the parameter name (valid if kind == PARAM_NAMED)
  *		id	   : the parameter id (valid if kind == PARAM_NUM)
- *				 or the attrno (if kind == PARAM_NEW or PARAM_OLD)
- *		type   : PG_TYPE OID of the value
- *		length : length in bytes of the value
- *		isnull : true if & only if the value is null (if true then
- *				 the fields 'length' and 'value' are undefined).
+ *		isnull : true if the value is null (if so 'value' is undefined)
  *		value  : the value that has to be substituted in the place
  *				 of the parameter.
  *
  *	 ParamListInfo is to be used as an array of ParamListInfoData
- *	 records. An 'InvalidName' in the name field of such a record
- *	 indicates that this is the last record in the array.
- *
- * ----------------------------------------------------------------
+ *	 records.  A dummy record with kind == PARAM_INVALID marks the end
+ *	 of the array.
+ * ----------------
  */
 
 typedef struct ParamListInfoData
@@ -83,19 +72,33 @@ typedef struct ParamListInfoData
 	int			kind;
 	char	   *name;
 	AttrNumber	id;
-	Oid			type;
-	Size		length;
 	bool		isnull;
-	bool		byval;
 	Datum		value;
 } ParamListInfoData;
 
 typedef ParamListInfoData *ParamListInfo;
 
+
+/* ----------------
+ *	  ParamExecData
+ *
+ *	  ParamExecData entries are used for executor internal parameters
+ *	  (that is, values being passed into or out of a sub-query).  The
+ *	  paramid of a PARAM_EXEC Param is a (zero-based) index into an
+ *	  array of ParamExecData records, which is referenced through
+ *	  es_param_exec_vals or ecxt_param_exec_vals.
+ *
+ *	  If execPlan is not NULL, it points to a SubPlan node that needs to
+ *	  be executed to produce the value.  (This is done so that we can have
+ *	  lazy evaluation of InitPlans: they aren't executed until/unless a
+ *	  result value is needed.)  Otherwise the value is assumed to be valid
+ *	  when needed.
+ * ----------------
+ */
+
 typedef struct ParamExecData
 {
-	void	   *execPlan;		/* plan must be executed to get param
-								 * value */
+	void	   *execPlan;		/* should be "SubPlan *" */
 	Datum		value;
 	bool		isnull;
 } ParamExecData;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 1d7c5115b64..f0f37c3d9d3 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -10,7 +10,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: primnodes.h,v 1.68 2002/09/18 21:35:24 tgl Exp $
+ * $Id: primnodes.h,v 1.69 2002/11/25 21:29:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -267,20 +267,16 @@ typedef struct Var
 typedef struct Const
 {
 	NodeTag		type;
-	Oid			consttype;		/* PG_TYPE OID of the constant's value */
-	int			constlen;		/* length in bytes of the constant's value */
+	Oid			consttype;		/* PG_TYPE OID of the constant's datatype */
+	int			constlen;		/* typlen of the constant's datatype */
 	Datum		constvalue;		/* the constant's value */
 	bool		constisnull;	/* whether the constant is null (if true,
-								 * the other fields are undefined) */
-	bool		constbyval;		/* whether the information in constvalue
-								 * if passed by value.	If true, then all
-								 * the information is stored in the datum.
-								 * If false, then the datum contains a
+								 * constvalue is undefined) */
+	bool		constbyval;		/* whether this datatype is passed by value.
+								 * If true, then all the information is
+								 * stored in the Datum.
+								 * If false, then the Datum contains a
 								 * pointer to the information. */
-	bool		constisset;		/* whether the const represents a set. The
-								 * const value corresponding will be the
-								 * query that defines the set. */
-	bool		constiscast;
 } Const;
 
 /* ----------------
@@ -290,31 +286,24 @@ typedef struct Const
  *
  *		PARAM_NAMED: The parameter has a name, i.e. something
  *				like `$.salary' or `$.foobar'.
- *				In this case field `paramname' must be a valid Name.
+ *				In this case field `paramname' must be a valid name.
  *
  *		PARAM_NUM:	 The parameter has only a numeric identifier,
  *				i.e. something like `$1', `$2' etc.
  *				The number is contained in the `paramid' field.
  *
- *		PARAM_NEW:	 Used in PRS2 rule, similar to PARAM_NAMED.
- *					 The `paramname' and `paramid' refer to the "NEW" tuple
- *					 The `pramname' is the attribute name and `paramid'
- *					 is the attribute number.
+ *		PARAM_EXEC:	 The parameter is an internal executor parameter.
+ *				It has a number contained in the `paramid' field.
  *
- *		PARAM_OLD:	 Same as PARAM_NEW, but in this case we refer to
- *				the "OLD" tuple.
  * ----------------
  */
 typedef struct Param
 {
 	NodeTag		type;
-	int			paramkind;		/* specifies the kind of parameter.  See
-								 * above */
-	AttrNumber	paramid;		/* numeric identifier for literal-constant
-								 * parameters ("$1") */
-	char	   *paramname;		/* attribute name for tuple-substitution
-								 * parameters ("$.foo") */
-	Oid			paramtype;		/* PG_TYPE OID of the parameter's value */
+	int			paramkind;		/* kind of parameter. See above */
+	AttrNumber	paramid;		/* numeric ID for parameter ("$1") */
+	char	   *paramname;		/* name for parameter ("$.foo") */
+	Oid			paramtype;		/* PG_TYPE OID of parameter's datatype */
 } Param;
 
 /*