7 files changed, 67 insertions, 1 deletions
diff --git a/src/include/access/amapi.h b/src/include/access/amapi.h
index 4325faa460b..85b4766016f 100644
--- a/src/include/access/amapi.h
+++ b/src/include/access/amapi.h
@@ -54,6 +54,42 @@ typedef enum IndexAMProperty
 	AMPROP_CAN_INCLUDE
 } IndexAMProperty;
 
+/*
+ * We use lists of this struct type to keep track of both operators and
+ * support functions while building or adding to an opclass or opfamily.
+ * amadjustmembers functions receive lists of these structs, and are allowed
+ * to alter their "ref" fields.
+ *
+ * The "ref" fields define how the pg_amop or pg_amproc entry should depend
+ * on the associated objects (that is, which dependency type to use, and
+ * which opclass or opfamily it should depend on).
+ *
+ * If ref_is_hard is true, the entry will have a NORMAL dependency on the
+ * operator or support func, and an INTERNAL dependency on the opclass or
+ * opfamily.  This forces the opclass or opfamily to be dropped if the
+ * operator or support func is dropped, and requires the CASCADE option
+ * to do so.  Nor will ALTER OPERATOR FAMILY DROP be allowed.  This is
+ * the right behavior for objects that are essential to an opclass.
+ *
+ * If ref_is_hard is false, the entry will have an AUTO dependency on the
+ * operator or support func, and also an AUTO dependency on the opclass or
+ * opfamily.  This allows ALTER OPERATOR FAMILY DROP, and causes that to
+ * happen automatically if the operator or support func is dropped.  This
+ * is the right behavior for inessential ("loose") objects.
+ */
+typedef struct OpFamilyMember
+{
+	bool		is_func;		/* is this an operator, or support func? */
+	Oid			object;			/* operator or support func's OID */
+	int			number;			/* strategy or support func number */
+	Oid			lefttype;		/* lefttype */
+	Oid			righttype;		/* righttype */
+	Oid			sortfamily;		/* ordering operator's sort opfamily, or 0 */
+	bool		ref_is_hard;	/* hard or soft dependency? */
+	bool		ref_is_family;	/* is dependency on opclass or opfamily? */
+	Oid			refobjid;		/* OID of opclass or opfamily */
+} OpFamilyMember;
+
 
 /*
  * Callback function signatures --- see indexam.sgml for more info.
@@ -114,6 +150,12 @@ typedef char *(*ambuildphasename_function) (int64 phasenum);
 /* validate definition of an opclass for this AM */
 typedef bool (*amvalidate_function) (Oid opclassoid);
 
+/* validate operators and support functions to be added to an opclass/family */
+typedef void (*amadjustmembers_function) (Oid opfamilyoid,
+										  Oid opclassoid,
+										  List *operators,
+										  List *functions);
+
 /* prepare for index scan */
 typedef IndexScanDesc (*ambeginscan_function) (Relation indexRelation,
 											   int nkeys,
@@ -224,6 +266,7 @@ typedef struct IndexAmRoutine
 	amproperty_function amproperty; /* can be NULL */
 	ambuildphasename_function ambuildphasename; /* can be NULL */
 	amvalidate_function amvalidate;
+	amadjustmembers_function amadjustmembers;	/* can be NULL */
 	ambeginscan_function ambeginscan;
 	amrescan_function amrescan;
 	amgettuple_function amgettuple; /* can be NULL */
diff --git a/src/include/access/amvalidate.h b/src/include/access/amvalidate.h
index f3a0e52d84e..149fc75f856 100644
--- a/src/include/access/amvalidate.h
+++ b/src/include/access/amvalidate.h
@@ -1,7 +1,8 @@
 /*-------------------------------------------------------------------------
  *
  * amvalidate.h
- *	  Support routines for index access methods' amvalidate functions.
+ *	  Support routines for index access methods' amvalidate and
+ *	  amadjustmembers functions.
  *
  * Copyright (c) 2016-2020, PostgreSQL Global Development Group
  *
@@ -32,6 +33,8 @@ extern bool check_amproc_signature(Oid funcid, Oid restype, bool exact,
 extern bool check_amoptsproc_signature(Oid funcid);
 extern bool check_amop_signature(Oid opno, Oid restype,
 								 Oid lefttype, Oid righttype);
+extern Oid	opclass_for_family_datatype(Oid amoid, Oid opfamilyoid,
+										Oid datatypeoid);
 extern bool opfamily_can_sort_type(Oid opfamilyoid, Oid datatypeoid);
 
 #endif							/* AMVALIDATE_H */
diff --git a/src/include/access/gin_private.h b/src/include/access/gin_private.h
index 71eeac205c9..5cb2f72e4cf 100644
--- a/src/include/access/gin_private.h
+++ b/src/include/access/gin_private.h
@@ -407,6 +407,10 @@ extern ItemPointer ginVacuumItemPointers(GinVacuumState *gvs,
 
 /* ginvalidate.c */
 extern bool ginvalidate(Oid opclassoid);
+extern void ginadjustmembers(Oid opfamilyoid,
+							 Oid opclassoid,
+							 List *operators,
+							 List *functions);
 
 /* ginbulk.c */
 typedef struct GinEntryAccumulator
diff --git a/src/include/access/gist_private.h b/src/include/access/gist_private.h
index 4bfc6280002..02e985549f6 100644
--- a/src/include/access/gist_private.h
+++ b/src/include/access/gist_private.h
@@ -464,6 +464,10 @@ extern bool gistcanreturn(Relation index, int attno);
 
 /* gistvalidate.c */
 extern bool gistvalidate(Oid opclassoid);
+extern void gistadjustmembers(Oid opfamilyoid,
+							  Oid opclassoid,
+							  List *operators,
+							  List *functions);
 
 /* gistutil.c */
 
diff --git a/src/include/access/hash.h b/src/include/access/hash.h
index 7e7b1b73d86..bab4d9f1b05 100644
--- a/src/include/access/hash.h
+++ b/src/include/access/hash.h
@@ -379,6 +379,10 @@ extern IndexBulkDeleteResult *hashvacuumcleanup(IndexVacuumInfo *info,
 												IndexBulkDeleteResult *stats);
 extern bytea *hashoptions(Datum reloptions, bool validate);
 extern bool hashvalidate(Oid opclassoid);
+extern void hashadjustmembers(Oid opfamilyoid,
+							  Oid opclassoid,
+							  List *operators,
+							  List *functions);
 
 /* private routines */
 
diff --git a/src/include/access/nbtree.h b/src/include/access/nbtree.h
index f5274cc7508..65d9698b899 100644
--- a/src/include/access/nbtree.h
+++ b/src/include/access/nbtree.h
@@ -1141,6 +1141,10 @@ extern bool _bt_allequalimage(Relation rel, bool debugmessage);
  * prototypes for functions in nbtvalidate.c
  */
 extern bool btvalidate(Oid opclassoid);
+extern void btadjustmembers(Oid opfamilyoid,
+							Oid opclassoid,
+							List *operators,
+							List *functions);
 
 /*
  * prototypes for functions in nbtsort.c
diff --git a/src/include/access/spgist.h b/src/include/access/spgist.h
index 852d1e2961a..9f2ccc1730f 100644
--- a/src/include/access/spgist.h
+++ b/src/include/access/spgist.h
@@ -220,5 +220,9 @@ extern IndexBulkDeleteResult *spgvacuumcleanup(IndexVacuumInfo *info,
 
 /* spgvalidate.c */
 extern bool spgvalidate(Oid opclassoid);
+extern void spgadjustmembers(Oid opfamilyoid,
+							 Oid opclassoid,
+							 List *operators,
+							 List *functions);
 
 #endif							/* SPGIST_H */