[##22388] YSQL: Change name of bitmap_exceeded_work_mem_cost

Summary:
Because `bitmap_exceeded_work_mem_cost` doesn't contain the phrase `disable_cost`, it's easy to
miss when someone try to find all the places that inflates the cost values, e.g.
investigate into cost overflow, precision losses with complex plans, etc.

Change the name to `bitmap_exceeded_work_mem_disable_cost`.
Jira: DB-11285

Test Plan: Jenkins: compile only, build type: debug

Reviewers: tnayak, amartsinchyk, mtakahara

Reviewed By: mtakahara

Subscribers: yql

Differential Revision: https://phorge.dev.yugabyte.com/D35045

src/postgres/src/backend/optimizer/path/costsize.c

@@ -172,7 +172,7 @@ double		yb_local_throughput_cost = YB_DEFAULT_LOCAL_THROUGHPUT_COST;
 int			effective_cache_size = DEFAULT_EFFECTIVE_CACHE_SIZE;
 
 Cost		disable_cost = 1.0e10;
-Cost		bitmap_exceeded_work_mem_cost = 5.0e9;
+Cost		bitmap_exceeded_work_mem_disable_cost = 5.0e9;
 
 int			max_parallel_workers_per_gather = 2;
 
@@ -1265,8 +1265,8 @@ yb_cost_bitmap_tree_node(Path *path, Cost *cost, Selectivity *selec, int *ybctid
 
 		double bitmap_rows = clamp_row_est(ipath->indexselectivity * ipath->path.parent->tuples);
 
-		if (bitmap_rows > maxentries && *cost < bitmap_exceeded_work_mem_cost)
-			*cost += bitmap_exceeded_work_mem_cost;
+		if (bitmap_rows > maxentries && *cost < bitmap_exceeded_work_mem_disable_cost)
+			*cost += bitmap_exceeded_work_mem_disable_cost;
 
 		/* Update the node cost with new calculations */
 		ipath->indextotalcost = *cost;
@@ -1359,11 +1359,11 @@ yb_cost_bitmap_and_node(BitmapAndPath *path, PlannerInfo *root)
 
 		selec *= subselec;
 
-		if (subcost < bitmap_exceeded_work_mem_cost)
+		if (subcost < bitmap_exceeded_work_mem_disable_cost)
 			startup_cost += subcost;
 		else
 		{
-			startup_cost += subcost - bitmap_exceeded_work_mem_cost;
+			startup_cost += subcost - bitmap_exceeded_work_mem_disable_cost;
 			exceeded_work_mem = true;
 		}
 
@@ -1376,7 +1376,7 @@ yb_cost_bitmap_and_node(BitmapAndPath *path, PlannerInfo *root)
 	}
 
 	if (exceeded_work_mem)
-		startup_cost += bitmap_exceeded_work_mem_cost;
+		startup_cost += bitmap_exceeded_work_mem_disable_cost;
 
 	path->bitmapselectivity = selec;
 	path->path.rows = least_rows * selec;
@@ -1439,11 +1439,11 @@ yb_cost_bitmap_or_node(BitmapOrPath *path, PlannerInfo *root)
 
 		selec += subselec;
 
-		if (subcost < bitmap_exceeded_work_mem_cost)
+		if (subcost < bitmap_exceeded_work_mem_disable_cost)
 			startup_cost += subcost;
 		else
 		{
-			startup_cost += subcost - bitmap_exceeded_work_mem_cost;
+			startup_cost += subcost - bitmap_exceeded_work_mem_disable_cost;
 			exceeded_work_mem = true;
 		}
 
@@ -1464,7 +1464,7 @@ yb_cost_bitmap_or_node(BitmapOrPath *path, PlannerInfo *root)
 	if (exceeded_work_mem ||
 		path->path.rows > yb_tbm_calculate_entries(work_mem * 1024L,
 												   path->ybctid_width))
-		startup_cost += bitmap_exceeded_work_mem_cost;
+		startup_cost += bitmap_exceeded_work_mem_disable_cost;
 
 	path->bitmapselectivity = Min(selec, 1.0);
 	path->path.rows = Min(path->path.parent->rows, total_rows) *
@@ -7472,7 +7472,7 @@ yb_cost_bitmap_table_scan(Path *path, PlannerInfo *root, RelOptInfo *baserel,
 	startup_cost += indexTotalCost;
 
 	/* we fall back to a sequential scan if we exceed work_mem */
-	if (indexTotalCost > bitmap_exceeded_work_mem_cost)
+	if (indexTotalCost > bitmap_exceeded_work_mem_disable_cost)
 	{
 		yb_cost_seqscan(path, root, baserel, param_info);
 		if (path->startup_cost > disable_cost)