Add compat version of create_merge_append_path routine and other light fixes

Author: Maksim Milyutin

src/compat/pg_compat.c

@@ -352,6 +352,28 @@ McxtStatsInternal(MemoryContext context, int level,
 #endif
 
 
+/*
+ * oid_cmp
+ *
+ * qsort comparison function for Oids;
+ * needed for find_inheritance_children_array() function
+ */
+#if PG_VERSION_NUM >= 90500 && PG_VERSION_NUM < 100000
+int
+oid_cmp(const void *p1, const void *p2)
+{
+	Oid			v1 = *((const Oid *) p1);
+	Oid			v2 = *((const Oid *) p2);
+
+	if (v1 < v2)
+		return -1;
+	if (v1 > v2)
+		return 1;
+	return 0;
+}
+#endif
+
+
 /*
  * set_dummy_rel_pathlist
  *	  Build a dummy path for a relation that's been excluded by constraints

src/include/compat/pg_compat.h

@@ -169,7 +169,7 @@ void CatalogIndexInsert(CatalogIndexState indstate, HeapTuple heapTuple);
  */
 #if PG_VERSION_NUM >= 100000
 #define create_append_path_compat(rel, subpaths, required_outer, parallel_workers) \
-		create_append_path((rel), (subpaths), (required_outer), (parallel_workers), NULL)
+		create_append_path((rel), (subpaths), (required_outer), (parallel_workers), NIL)
 #elif PG_VERSION_NUM >= 90600
 
 #ifndef PGPRO_VERSION
@@ -187,6 +187,22 @@ void CatalogIndexInsert(CatalogIndexState indstate, HeapTuple heapTuple);
 #endif /* PG_VERSION_NUM */
 
 
+/*
+ * create_merge_append_path()
+ */
+#if PG_VERSION_NUM >= 100000
+#define create_merge_append_path_compat(root, rel, subpaths, pathkeys, \
+										required_outer) \
+		create_merge_append_path((root), (rel), (subpaths), (pathkeys), \
+								 (required_outer), NIL)
+#elif PG_VERSION_NUM >= 90500
+#define create_merge_append_path_compat(root, rel, subpaths, pathkeys, \
+										required_outer) \
+		create_merge_append_path((root), (rel), (subpaths), (pathkeys), \
+								 (required_outer))
+#endif
+
+
 /*
  * create_nestloop_path()
  */
@@ -418,6 +434,14 @@ void McxtStatsInternal(MemoryContext context, int level,
 #endif
 
 
+/*
+ * oid_cmp()
+ */
+#if PG_VERSION_NUM >=90500 && PG_VERSION_NUM < 100000
+extern int oid_cmp(const void *p1, const void *p2);
+#endif
+
+
 /*
  * parse_analyze()
  *
@@ -512,6 +536,20 @@ extern void set_rel_consider_parallel(PlannerInfo *root,
 #endif
 
 
+/*
+ * tlist_member_ignore_relabel()
+ *
+ * in compat version the type of first argument is (Expr *)
+ */
+#if PG_VERSION_NUM >= 100000
+#define tlist_member_ignore_relabel_compat(expr, targetlist) \
+		tlist_member_ignore_relabel((expr), (targetlist))
+#elif PG_VERSION_NUM >= 90500
+#define tlist_member_ignore_relabel_compat(expr, targetlist) \
+		tlist_member_ignore_relabel((Node *) (expr), (targetlist))
+#endif
+
+
 /*
  * -------------
  *  Common code

src/init.c

@@ -82,10 +82,6 @@ static bool read_opexpr_const(const OpExpr *opexpr,
 							  const PartRelationInfo *prel,
 							  Datum *value);
 
-#if PG_VERSION_NUM < 100000
-static int oid_cmp(const void *p1, const void *p2);
-#endif
-
 
 /* Validate SQL facade */
 static uint32 build_sql_facade_version(char *version_cstr);
@@ -1127,23 +1123,6 @@ validate_hash_constraint(const Expr *expr,
 	return false;
 }
 
-#if PG_VERSION_NUM < 100000
-/* needed for find_inheritance_children_array() function */
-static int
-oid_cmp(const void *p1, const void *p2)
-{
-	Oid			v1 = *((const Oid *) p1);
-	Oid			v2 = *((const Oid *) p2);
-
-	if (v1 < v2)
-		return -1;
-	if (v1 > v2)
-		return 1;
-	return 0;
-}
-#endif
-
-
 /* Parse cstring and build uint32 representing the version */
 static uint32
 build_sql_facade_version(char *version_cstr)

src/nodes_common.c

@@ -7,6 +7,7 @@
  *
  * ------------------------------------------------------------------------
  */
+#include "compat/pg_compat.h"
 
 #include "init.h"
 #include "nodes_common.h"
@@ -175,13 +176,8 @@ tlist_is_var_subset(List *a, List *b)
 		if (!IsA(te->expr, Var) && !IsA(te->expr, RelabelType))
 			continue;
 
-#if PG_VERSION_NUM >= 100000
-		if (!tlist_member_ignore_relabel(te->expr, a))
-			return true;
-#else
-		if (!tlist_member_ignore_relabel((Node *) te->expr, a))
+		if (!tlist_member_ignore_relabel_compat(te->expr, a))
 			return true;
-#endif
 	}
 
 	return false;

src/pg_pathman.c

@@ -1575,33 +1575,11 @@ generate_mergeappend_paths(PlannerInfo *root, RelOptInfo *rel,
 		else
 		{
 			/* ... and build the MergeAppend paths */
-#if PG_VERSION_NUM >= 100000
-			add_path(rel, (Path *) create_merge_append_path(root,
-															rel,
-															startup_subpaths,
-															pathkeys,
-															NULL,
-															NULL));
+			add_path(rel, (Path *) create_merge_append_path_compat(
+							root, rel, startup_subpaths, pathkeys, NULL));
 			if (startup_neq_total)
-				add_path(rel, (Path *) create_merge_append_path(root,
-																rel,
-																total_subpaths,
-																pathkeys,
-																NULL,
-																NULL));
-#else
-			add_path(rel, (Path *) create_merge_append_path(root,
-															rel,
-															startup_subpaths,
-															pathkeys,
-															NULL));
-			if (startup_neq_total)
-				add_path(rel, (Path *) create_merge_append_path(root,
-																rel,
-																total_subpaths,
-																pathkeys,
-																NULL));
-#endif
+				add_path(rel, (Path *) create_merge_append_path_compat(
+								root, rel, total_subpaths, pathkeys, NULL));
 		}
 	}
 }