Abstract logic to allow for multiple kinds of child rels.

Currently, the only type of child relation is an "other member rel",
which is the child of a baserel, but in the future joins and even
upper relations may have child rels.  To facilitate that, introduce
macros that test to test for particular RelOptKind values, and use
them in various places where they help to clarify the sense of a test.
(For example, a test may allow RELOPT_OTHER_MEMBER_REL either because
it intends to allow child rels, or because it intends to allow simple
rels.)

Also, remove find_childrel_top_parent, which will not work for a
child rel that is not a baserel.  Instead, add a new RelOptInfo
member top_parent_relids to track the same kind of information in a
more generic manner.

Ashutosh Bapat, slightly tweaked by me.  Review and testing of the
patch set from which this was taken by Rajkumar Raghuwanshi and Rafia
Sabih.

Discussion: http://postgr.es/m/CA+TgmoagTnF2yqR3PT2rv=om=wJiZ4-A+ATwdnriTGku1CLYxA@mail.gmail.com

1 files changed, 16 insertions, 26 deletions

diff --git a/contrib/postgres_fdw/deparse.c b/contrib/postgres_fdw/deparse.c
index 1d7ec28806d..129bdb549ff 100644
--- a/contrib/postgres_fdw/deparse.c
+++ b/contrib/postgres_fdw/deparse.c
@@ -243,7 +243,7 @@ is_foreign_expr(PlannerInfo *root,
 	 * because the upperrel's own relids currently aren't set to anything
 	 * meaningful by the core code.  For other relation, use their own relids.
 	 */
-	if (baserel->reloptkind == RELOPT_UPPER_REL)
+	if (IS_UPPER_REL(baserel))
 		glob_cxt.relids = fpinfo->outerrel->relids;
 	else
 		glob_cxt.relids = baserel->relids;
@@ -677,7 +677,7 @@ foreign_expr_walker(Node *node,
 				ListCell   *lc;
 
 				/* Not safe to pushdown when not in grouping context */
-				if (glob_cxt->foreignrel->reloptkind != RELOPT_UPPER_REL)
+				if (!IS_UPPER_REL(glob_cxt->foreignrel))
 					return false;
 
 				/* Only non-split aggregates are pushable. */
@@ -874,7 +874,7 @@ build_tlist_to_deparse(RelOptInfo *foreignrel)
 	 * For an upper relation, we have already built the target list while
 	 * checking shippability, so just return that.
 	 */
-	if (foreignrel->reloptkind == RELOPT_UPPER_REL)
+	if (IS_UPPER_REL(foreignrel))
 		return fpinfo->grouped_tlist;
 
 	/*
@@ -929,17 +929,13 @@ deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel,
 	 * We handle relations for foreign tables, joins between those and upper
 	 * relations.
 	 */
-	Assert(rel->reloptkind == RELOPT_JOINREL ||
-		   rel->reloptkind == RELOPT_BASEREL ||
-		   rel->reloptkind == RELOPT_OTHER_MEMBER_REL ||
-		   rel->reloptkind == RELOPT_UPPER_REL);
+	Assert(IS_JOIN_REL(rel) || IS_SIMPLE_REL(rel) || IS_UPPER_REL(rel));
 
 	/* Fill portions of context common to upper, join and base relation */
 	context.buf = buf;
 	context.root = root;
 	context.foreignrel = rel;
-	context.scanrel = (rel->reloptkind == RELOPT_UPPER_REL) ?
-		fpinfo->outerrel : rel;
+	context.scanrel = IS_UPPER_REL(rel) ? fpinfo->outerrel : rel;
 	context.params_list = params_list;
 
 	/* Construct SELECT clause */
@@ -950,7 +946,7 @@ deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel,
 	 * conditions of the underlying scan relation; otherwise, we can use the
 	 * supplied list of remote conditions directly.
 	 */
-	if (rel->reloptkind == RELOPT_UPPER_REL)
+	if (IS_UPPER_REL(rel))
 	{
 		PgFdwRelationInfo *ofpinfo;
 
@@ -963,7 +959,7 @@ deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel,
 	/* Construct FROM and WHERE clauses */
 	deparseFromExpr(quals, &context);
 
-	if (rel->reloptkind == RELOPT_UPPER_REL)
+	if (IS_UPPER_REL(rel))
 	{
 		/* Append GROUP BY clause */
 		appendGroupByClause(tlist, &context);
@@ -1020,8 +1016,7 @@ deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
 		 */
 		deparseSubqueryTargetList(context);
 	}
-	else if (foreignrel->reloptkind == RELOPT_JOINREL ||
-			 foreignrel->reloptkind == RELOPT_UPPER_REL)
+	else if (IS_JOIN_REL(foreignrel) || IS_UPPER_REL(foreignrel))
 	{
 		/*
 		 * For a join or upper relation the input tlist gives the list of
@@ -1062,9 +1057,8 @@ deparseFromExpr(List *quals, deparse_expr_cxt *context)
 	RelOptInfo *scanrel = context->scanrel;
 
 	/* For upper relations, scanrel must be either a joinrel or a baserel */
-	Assert(context->foreignrel->reloptkind != RELOPT_UPPER_REL ||
-		   scanrel->reloptkind == RELOPT_JOINREL ||
-		   scanrel->reloptkind == RELOPT_BASEREL);
+	Assert(!IS_UPPER_REL(context->foreignrel) ||
+		   IS_JOIN_REL(scanrel) || IS_SIMPLE_REL(scanrel));
 
 	/* Construct FROM clause */
 	appendStringInfoString(buf, " FROM ");
@@ -1219,7 +1213,7 @@ deparseLockingClause(deparse_expr_cxt *context)
 			appendStringInfoString(buf, " FOR UPDATE");
 
 			/* Add the relation alias if we are here for a join relation */
-			if (rel->reloptkind == RELOPT_JOINREL)
+			if (IS_JOIN_REL(rel))
 				appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
 		}
 		else
@@ -1384,8 +1378,7 @@ deparseSubqueryTargetList(deparse_expr_cxt *context)
 	ListCell   *lc;
 
 	/* Should only be called in these cases. */
-	Assert(foreignrel->reloptkind == RELOPT_BASEREL ||
-		   foreignrel->reloptkind == RELOPT_JOINREL);
+	Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
 
 	first = true;
 	foreach(lc, foreignrel->reltarget->exprs)
@@ -1417,7 +1410,7 @@ deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
 {
 	PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
 
-	if (foreignrel->reloptkind == RELOPT_JOINREL)
+	if (IS_JOIN_REL(foreignrel))
 	{
 		StringInfoData join_sql_o;
 		StringInfoData join_sql_i;
@@ -1495,8 +1488,7 @@ deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
 	PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
 
 	/* Should only be called in these cases. */
-	Assert(foreignrel->reloptkind == RELOPT_BASEREL ||
-		   foreignrel->reloptkind == RELOPT_JOINREL);
+	Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
 
 	Assert(fpinfo->local_conds == NIL);
 
@@ -3097,15 +3089,13 @@ is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
 	RelOptInfo *innerrel = fpinfo->innerrel;
 
 	/* Should only be called in these cases. */
-	Assert(foreignrel->reloptkind == RELOPT_BASEREL ||
-		   foreignrel->reloptkind == RELOPT_JOINREL ||
-		   foreignrel->reloptkind == RELOPT_OTHER_MEMBER_REL);
+	Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
 
 	/*
 	 * If the given relation isn't a join relation, it doesn't have any lower
 	 * subqueries, so the Var isn't a subquery output column.
 	 */
-	if (foreignrel->reloptkind != RELOPT_JOINREL)
+	if (!IS_JOIN_REL(foreignrel))
 		return false;
 
 	/*