1 files changed, 6 insertions, 14 deletions

diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index d01630f8dba..c138f57ebb4 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -682,9 +682,8 @@ extract_nonindex_conditions(List *qual_clauses, List *indexquals)
 
 	foreach(lc, qual_clauses)
 	{
-		RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
+		RestrictInfo *rinfo = castNode(RestrictInfo, lfirst(lc));
 
-		Assert(IsA(rinfo, RestrictInfo));
 		if (rinfo->pseudoconstant)
 			continue;			/* we may drop pseudoconstants here */
 		if (list_member_ptr(indexquals, rinfo))
@@ -1804,12 +1803,10 @@ cost_windowagg(Path *path, PlannerInfo *root,
 	 */
 	foreach(lc, windowFuncs)
 	{
-		WindowFunc *wfunc = (WindowFunc *) lfirst(lc);
+		WindowFunc *wfunc = castNode(WindowFunc, lfirst(lc));
 		Cost		wfunccost;
 		QualCost	argcosts;
 
-		Assert(IsA(wfunc, WindowFunc));
-
 		wfunccost = get_func_cost(wfunc->winfnoid) * cpu_operator_cost;
 
 		/* also add the input expressions' cost to per-input-row costs */
@@ -2843,11 +2840,9 @@ final_cost_hashjoin(PlannerInfo *root, HashPath *path,
 		innerbucketsize = 1.0;
 		foreach(hcl, hashclauses)
 		{
-			RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(hcl);
+			RestrictInfo *restrictinfo = castNode(RestrictInfo, lfirst(hcl));
 			Selectivity thisbucketsize;
 
-			Assert(IsA(restrictinfo, RestrictInfo));
-
 			/*
 			 * First we have to figure out which side of the hashjoin clause
 			 * is the inner side.
@@ -3537,9 +3532,8 @@ compute_semi_anti_join_factors(PlannerInfo *root,
 		joinquals = NIL;
 		foreach(l, restrictlist)
 		{
-			RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
+			RestrictInfo *rinfo = castNode(RestrictInfo, lfirst(l));
 
-			Assert(IsA(rinfo, RestrictInfo));
 			if (!rinfo->is_pushed_down)
 				joinquals = lappend(joinquals, rinfo);
 		}
@@ -3970,9 +3964,8 @@ calc_joinrel_size_estimate(PlannerInfo *root,
 		/* Grovel through the clauses to separate into two lists */
 		foreach(l, restrictlist)
 		{
-			RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
+			RestrictInfo *rinfo = castNode(RestrictInfo, lfirst(l));
 
-			Assert(IsA(rinfo, RestrictInfo));
 			if (rinfo->is_pushed_down)
 				pushedquals = lappend(pushedquals, rinfo);
 			else
@@ -4345,11 +4338,10 @@ set_subquery_size_estimates(PlannerInfo *root, RelOptInfo *rel)
 	 */
 	foreach(lc, subroot->parse->targetList)
 	{
-		TargetEntry *te = (TargetEntry *) lfirst(lc);
+		TargetEntry *te = castNode(TargetEntry, lfirst(lc));
 		Node	   *texpr = (Node *) te->expr;
 		int32		item_width = 0;
 
-		Assert(IsA(te, TargetEntry));
 		/* junk columns aren't visible to upper query */
 		if (te->resjunk)
 			continue;