Load FK defs into relcache for use by planner

Fastpath ignores this if no triggers defined.

Author: Tomas Vondra, with fastpath and comments added by me
Reviewers: David Rowley, Simon Riggs

4 files changed, 27 insertions, 0 deletions

diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 3f22bdb5a8a..84efa8e886d 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -223,6 +223,7 @@ typedef enum NodeTag
 	T_PlannerGlobal,
 	T_RelOptInfo,
 	T_IndexOptInfo,
+	T_ForeignKeyOptInfo,
 	T_ParamPathInfo,
 	T_Path,
 	T_IndexPath,
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h
index 5264d3cc76d..d430f6e9fd4 100644
--- a/src/include/nodes/relation.h
+++ b/src/include/nodes/relation.h
@@ -516,6 +516,7 @@ typedef struct RelOptInfo
 	List	   *lateral_vars;	/* LATERAL Vars and PHVs referenced by rel */
 	Relids		lateral_referencers;	/* rels that reference me laterally */
 	List	   *indexlist;		/* list of IndexOptInfo */
+	List	   *fkeylist;			/* list of ForeignKeyOptInfo */
 	BlockNumber pages;			/* size estimates derived from pg_class */
 	double		tuples;
 	double		allvisfrac;
@@ -621,6 +622,27 @@ typedef struct IndexOptInfo
 	void		(*amcostestimate) ();	/* AM's cost estimator */
 } IndexOptInfo;
 
+/*
+ * ForeignKeyOptInfo
+ *		Per-foreign-key information for planning/optimization
+ *
+ * Only includes columns from pg_constraint related to foreign keys.
+ *
+ * conkeys[], confkeys[] and conpfeqop[] each have nkeys entries.
+ */
+typedef struct ForeignKeyOptInfo
+{
+	NodeTag		type;
+
+	Oid			conrelid;	/* relation constrained by the foreign key */
+	Oid			confrelid;	/* relation referenced by the foreign key */
+
+	int			nkeys;		/* number of columns in the foreign key */
+	int		   *conkeys;	/* attnums of columns in the constrained table */
+	int		   *confkeys;	/* attnums of columns in the referenced table */
+	Oid		   *conpfeqop;	/* OIDs of equality operators used by the FK */
+
+} ForeignKeyOptInfo;
 
 /*
  * EquivalenceClasses
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index f2bebf2c3dd..51eb27a381b 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -94,6 +94,9 @@ typedef struct RelationData
 	Oid			rd_oidindex;	/* OID of unique index on OID, if any */
 	Oid			rd_replidindex; /* OID of replica identity index, if any */
 
+	/* data managed by RelationGetFKList: */
+	List	   *rd_fkeylist;		/* OIDs of foreign keys */
+
 	/* data managed by RelationGetIndexAttrBitmap: */
 	Bitmapset  *rd_indexattr;	/* identifies columns used in indexes */
 	Bitmapset  *rd_keyattr;		/* cols that can be ref'd by foreign keys */
diff --git a/src/include/utils/relcache.h b/src/include/utils/relcache.h
index 1b4830462d5..7f07c269145 100644
--- a/src/include/utils/relcache.h
+++ b/src/include/utils/relcache.h
@@ -38,6 +38,7 @@ extern void RelationClose(Relation relation);
  * Routines to compute/retrieve additional cached information
  */
 extern List *RelationGetIndexList(Relation relation);
+extern List *RelationGetFKeyList(Relation relation);
 extern Oid	RelationGetOidIndex(Relation relation);
 extern Oid	RelationGetReplicaIndex(Relation relation);
 extern List *RelationGetIndexExpressions(Relation relation);