Remove dead code in outfuncs.c (#714)

The reason to remove them is because: print_variable_fields is initialized
to true, and only set to false in outfuncs_workfile_mgr_init() function.
But outfuncs_workfile_mgr_init() is never called. So we can remove all of:
print_variable_fields, outfuncs_workfile_mgr_init(), outfuncs_workfile_mgr_end(),
and all the if() tests depending on print_variable_fields.

Co-authored-by: Kuien Liu and Heikki Linnakangas

src/backend/nodes/outfuncs.c

@@ -142,13 +142,6 @@
 
 static void _outNode(StringInfo str, void *obj);
 
-
-/* When serializing a plan for workfile caching, we want to leave out
- * all variable fields by setting this to false */
-static bool print_variable_fields = true;
-/* rtable needed when serializing for workfile caching */
-static List *range_table = NULL;
-
 /*
  * _outToken
  *	  Convert an ordinary string (eg, an identifier) into a form that
@@ -338,16 +331,13 @@ _outPlannedStmt(StringInfo str, PlannedStmt *node)
 static void
 _outPlanInfo(StringInfo str, Plan *node)
 {
-	if (print_variable_fields)
-	{
-		WRITE_INT_FIELD(plan_node_id);
-		WRITE_INT_FIELD(plan_parent_node_id);
+	WRITE_INT_FIELD(plan_node_id);
+	WRITE_INT_FIELD(plan_parent_node_id);
 
-		WRITE_FLOAT_FIELD(startup_cost, "%.2f");
-		WRITE_FLOAT_FIELD(total_cost, "%.2f");
-		WRITE_FLOAT_FIELD(plan_rows, "%.0f");
-		WRITE_INT_FIELD(plan_width);
-	}
+	WRITE_FLOAT_FIELD(startup_cost, "%.2f");
+	WRITE_FLOAT_FIELD(total_cost, "%.2f");
+	WRITE_FLOAT_FIELD(plan_rows, "%.0f");
+	WRITE_INT_FIELD(plan_width);
 
 	WRITE_NODE_FIELD(targetlist);
 	WRITE_NODE_FIELD(qual);
@@ -357,23 +347,17 @@ _outPlanInfo(StringInfo str, Plan *node)
 
 	WRITE_INT_FIELD(nParamExec);
 
-	if (print_variable_fields)
-	{
-		WRITE_NODE_FIELD(flow);
-		WRITE_ENUM_FIELD(dispatch, DispatchMethod);
-		WRITE_INT_FIELD(nMotionNodes);
-		WRITE_INT_FIELD(nInitPlans);
-		WRITE_NODE_FIELD(sliceTable);
-	}
+	WRITE_NODE_FIELD(flow);
+	WRITE_ENUM_FIELD(dispatch, DispatchMethod);
+	WRITE_INT_FIELD(nMotionNodes);
+	WRITE_INT_FIELD(nInitPlans);
+	WRITE_NODE_FIELD(sliceTable);
 
 	WRITE_NODE_FIELD(lefttree);
 	WRITE_NODE_FIELD(righttree);
 	WRITE_NODE_FIELD(initPlan);
 
-	if (print_variable_fields)
-	{
-		WRITE_UINT64_FIELD(operatorMemKB);
-	}
+	WRITE_UINT64_FIELD(operatorMemKB);
 }
 #endif /* COMPILING_BINARY_FUNCS */
 
@@ -385,30 +369,7 @@ _outScanInfo(StringInfo str, Scan *node)
 {
 	_outPlanInfo(str, (Plan *) node);
 
-	if (print_variable_fields)
-	{
-		WRITE_UINT_FIELD(scanrelid);
-	}
-	else
-	{
-		/*
-		 * Serializing for workfile caching.
-		 * Instead of outputing rtable indices, serialize the actual rtable entry
-		 */
-		Assert(range_table != NULL);
-
-		RangeTblEntry *rte = rt_fetch(node->scanrelid, range_table);
-		/*
-		 * Serialize all rtable entries except for subquery type.
-		 * For subquery scan, the rtable entry contains the entire plan of the
-		 * subquery, but this is serialized elsewhere in outSubqueryScan, no
-		 * need to duplicate it here
-		 */
-		if (rte->rtekind != RTE_SUBQUERY)
-		{
-			_outNode(str,rte);
-		}
-	}
+	WRITE_UINT_FIELD(scanrelid);
 
 	WRITE_INT_FIELD(partIndex);
 	WRITE_INT_FIELD(partIndexPrintable);
@@ -794,11 +755,8 @@ _outAgg(StringInfo str, Agg *node)
 	for (i = 0; i < node->numCols; i++)
 		appendStringInfo(str, " %u", node->grpOperators[i]);
 
-	if (print_variable_fields)
-	{
-		WRITE_LONG_FIELD(numGroups);
-		WRITE_INT_FIELD(transSpace);
-	}
+	WRITE_LONG_FIELD(numGroups);
+	WRITE_INT_FIELD(transSpace);
 	WRITE_INT_FIELD(numNullCols);
 	WRITE_UINT64_FIELD(inputGrouping);
 	WRITE_UINT64_FIELD(grouping);
@@ -1182,18 +1140,12 @@ _outVar(StringInfo str, Var *node)
 {
 	WRITE_NODE_TYPE("VAR");
 
-	if (print_variable_fields)
-	{
-		WRITE_UINT_FIELD(varno);
-	}
+	WRITE_UINT_FIELD(varno);
 	WRITE_INT_FIELD(varattno);
 	WRITE_OID_FIELD(vartype);
 	WRITE_INT_FIELD(vartypmod);
 	WRITE_UINT_FIELD(varlevelsup);
-	if (print_variable_fields)
-	{
-		WRITE_UINT_FIELD(varnoold);
-	}
+	WRITE_UINT_FIELD(varnoold);
 	WRITE_INT_FIELD(varoattno);
 }
 
@@ -5132,35 +5084,6 @@ _outNode(StringInfo str, void *obj)
 	}
 }
 
-/*
- * Initialize global variables for serializing a plan for the workfile manager.
- * The serialized form of a plan for workfile manager does not include some
- * variable fields such as costs and node ids.
- * In addition, range table pointers are replaced with Oids where applicable.
- */
-void
-outfuncs_workfile_mgr_init(List *rtable)
-{
-	Assert(NULL == range_table);
-	Assert(print_variable_fields);
-	range_table = rtable;
-	print_variable_fields = false;
-}
-
-/*
- * Reset global variables to their default values at the end of serializing
- * a plan for the workfile manager.
- */
-void
-outfuncs_workfile_mgr_end()
-{
-	Assert(range_table != NULL);
-	Assert(!print_variable_fields);
-
-	print_variable_fields = true;
-	range_table = NULL;
-}
-
 /*
  * nodeToString -
  *	   returns the ascii representation of the Node as a palloc'd string

src/include/utils/workfile_mgr.h

@@ -198,14 +198,9 @@ bool WorkfileQueryspace_AddWorkfile(void);
 void WorkfileQueryspace_SubtractWorkfile(int32 nFiles);
 
 /* Serialization functions */
-void outfuncs_workfile_mgr_init(List *rtable);
-void outfuncs_workfile_mgr_end(void);
 void outfast_workfile_mgr_init(List *rtable);
 void outfast_workfile_mgr_end(void);
 
-/* Debugging functions */
-void workfile_mgr_print_set(workfile_set *work_set);
-
 /* Workfile error reporting */
 typedef enum WorkfileError
 {