refactoring in walk_expr_tree()'s machinery

Author: funbringer

expected/pathman_basic.out

@@ -450,6 +450,13 @@ EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel;
    ->  Seq Scan on hash_rel_2
 (4 rows)
 
+EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel WHERE false;
+        QUERY PLAN        
+--------------------------
+ Result
+   One-Time Filter: false
+(2 rows)
+
 EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel WHERE value = NULL;
         QUERY PLAN        
 --------------------------
@@ -609,6 +616,13 @@ EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel;
    ->  Seq Scan on hash_rel_2
 (4 rows)
 
+EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel WHERE false;
+        QUERY PLAN        
+--------------------------
+ Result
+   One-Time Filter: false
+(2 rows)
+
 EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel WHERE value = NULL;
         QUERY PLAN        
 --------------------------

sql/pathman_basic.sql

@@ -165,6 +165,7 @@ SET enable_bitmapscan = OFF;
 SET enable_seqscan = ON;
 
 EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel;
+EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel WHERE false;
 EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel WHERE value = NULL;
 EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel WHERE value = 2;
 EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel WHERE value = 2 OR value = 1;
@@ -189,6 +190,7 @@ SET enable_bitmapscan = OFF;
 SET enable_seqscan = OFF;
 
 EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel;
+EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel WHERE false;
 EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel WHERE value = NULL;
 EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel WHERE value = 2;
 EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel WHERE value = 2 OR value = 1;

src/hooks.c

@@ -137,7 +137,7 @@ pathman_join_pathlist_hook(PlannerInfo *root,
 	{
 		WrapperNode *wrap;
 
-		InitWalkerContext(&context, part_expr, inner_prel, NULL, false);
+		InitWalkerContext(&context, part_expr, inner_prel, NULL);
 		wrap = walk_expr_tree((Expr *) lfirst(lc), &context);
 		paramsel *= wrap->paramsel;
 	}
@@ -345,7 +345,7 @@ pathman_rel_pathlist_hook(PlannerInfo *root,
 		ranges = list_make1_irange_full(prel, IR_COMPLETE);
 
 		/* Make wrappers over restrictions and collect final rangeset */
-		InitWalkerContext(&context, part_expr, prel, NULL, false);
+		InitWalkerContext(&context, part_expr, prel, NULL);
 		wrappers = NIL;
 		foreach(lc, rel->baserestrictinfo)
 		{

src/include/pathman.h

@@ -146,16 +146,14 @@ typedef struct
 	Node				   *prel_expr;		/* expression from PartRelationInfo */
 	const PartRelationInfo *prel;			/* main partitioning structure */
 	ExprContext			   *econtext;		/* for ExecEvalExpr() */
-	bool					for_insert;		/* are we in PartitionFilter now? */
 } WalkerContext;
 
 /* Usual initialization procedure for WalkerContext */
-#define InitWalkerContext(context, expr, prel_info, ecxt, for_ins) \
+#define InitWalkerContext(context, expr, prel_info, ecxt) \
 	do { \
 		(context)->prel_expr = (expr); \
 		(context)->prel = (prel_info); \
 		(context)->econtext = (ecxt); \
-		(context)->for_insert = (for_ins); \
 	} while (0)
 
 /* Check that WalkerContext contains ExprContext (plan execution stage) */
@@ -166,11 +164,11 @@ WrapperNode *walk_expr_tree(Expr *expr, WalkerContext *context);
 
 
 void select_range_partitions(const Datum value,
+							 const Oid collid,
 							 FmgrInfo *cmp_func,
 							 const RangeEntry *ranges,
 							 const int nranges,
 							 const int strategy,
-							 const Oid collid,
 							 WrapperNode *result);
 
 

src/nodes_common.c

@@ -723,7 +723,7 @@ rescan_append_common(CustomScanState *node)
 	/* First we select all available partitions... */
 	ranges = list_make1_irange_full(prel, IR_COMPLETE);
 
-	InitWalkerContext(&wcxt, prel_expr, prel, econtext, false);
+	InitWalkerContext(&wcxt, prel_expr, prel, econtext);
 	foreach (lc, scan_state->canon_custom_exprs)
 	{
 		WrapperNode *wn;

src/partition_filter.c

@@ -402,7 +402,7 @@ find_partitions_for_value(Datum value, Oid value_type,
 	CopyToTempConst(constbyval,  ev_byval);
 
 	/* We use 0 since varno doesn't matter for Const */
-	InitWalkerContext(&wcxt, 0, prel, NULL, true);
+	InitWalkerContext(&wcxt, 0, prel, NULL);
 	ranges = walk_expr_tree((Expr *) &temp_const, &wcxt)->rangeset;
 
 	return get_partition_oids(ranges, nparts, prel, false);