diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index e88f7efa7e..d6be1955b7 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -91,6 +91,7 @@ brinhandler(PG_FUNCTION_ARGS)
 {
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
+	amroutine->amstrategy_am = BRIN_AM_OID;
 	amroutine->amstrategies = 0;
 	amroutine->amsupport = BRIN_LAST_OPTIONAL_PROCNUM;
 	amroutine->amoptsprocnum = BRIN_PROCNUM_OPTIONS;
diff --git a/src/backend/access/gin/ginutil.c b/src/backend/access/gin/ginutil.c
index 6df7f2eaeb..7f35109c76 100644
--- a/src/backend/access/gin/ginutil.c
+++ b/src/backend/access/gin/ginutil.c
@@ -39,6 +39,7 @@ ginhandler(PG_FUNCTION_ARGS)
 {
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
+	amroutine->amstrategy_am = GIN_AM_OID;
 	amroutine->amstrategies = 0;
 	amroutine->amsupport = GINNProcs;
 	amroutine->amoptsprocnum = GIN_OPTIONS_PROC;
diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c
index 5866c6aaaf..8f0144375b 100644
--- a/src/backend/access/gist/gist.c
+++ b/src/backend/access/gist/gist.c
@@ -17,6 +17,7 @@
 #include "access/gist_private.h"
 #include "access/gistscan.h"
 #include "access/xloginsert.h"
+#include "catalog/pg_am_d.h"
 #include "catalog/pg_collation.h"
 #include "commands/vacuum.h"
 #include "miscadmin.h"
@@ -61,6 +62,7 @@ gisthandler(PG_FUNCTION_ARGS)
 {
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
+	amroutine->amstrategy_am = GIST_AM_OID;
 	amroutine->amstrategies = 0;
 	amroutine->amsupport = GISTNProcs;
 	amroutine->amoptsprocnum = GIST_OPTIONS_PROC;
diff --git a/src/backend/access/hash/hash.c b/src/backend/access/hash/hash.c
index c361509d68..2de916dde8 100644
--- a/src/backend/access/hash/hash.c
+++ b/src/backend/access/hash/hash.c
@@ -58,6 +58,7 @@ hashhandler(PG_FUNCTION_ARGS)
 {
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
+	amroutine->amstrategy_am = HASH_AM_OID;
 	amroutine->amstrategies = HTMaxStrategyNumber;
 	amroutine->amsupport = HASHNProcs;
 	amroutine->amoptsprocnum = HASHOPTIONS_PROC;
diff --git a/src/backend/access/index/amapi.c b/src/backend/access/index/amapi.c
index 2b028e1950..0c4a10b8b7 100644
--- a/src/backend/access/index/amapi.c
+++ b/src/backend/access/index/amapi.c
@@ -141,3 +141,11 @@ amvalidate(PG_FUNCTION_ARGS)
 
 	PG_RETURN_BOOL(result);
 }
+
+Oid
+get_amstrategy_am(Oid indexam_oid)
+{
+	IndexAmRoutine *indexAm = GetIndexAmRoutineByAmId(indexam_oid, false);
+
+	return indexAm->amstrategy_am;
+}
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
index b52eca8f38..be6b6dc9c3 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/src/backend/access/nbtree/nbtree.c
@@ -97,6 +97,7 @@ bthandler(PG_FUNCTION_ARGS)
 {
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
+	amroutine->amstrategy_am = BTREE_AM_OID;
 	amroutine->amstrategies = BTMaxStrategyNumber;
 	amroutine->amsupport = BTNProcs;
 	amroutine->amoptsprocnum = BTOPTIONS_PROC;
diff --git a/src/backend/access/spgist/spgutils.c b/src/backend/access/spgist/spgutils.c
index 2c661fcf96..0b49099076 100644
--- a/src/backend/access/spgist/spgutils.c
+++ b/src/backend/access/spgist/spgutils.c
@@ -45,6 +45,7 @@ spghandler(PG_FUNCTION_ARGS)
 {
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
+	amroutine->amstrategy_am = SPGIST_AM_OID;
 	amroutine->amstrategies = 0;
 	amroutine->amsupport = SPGISTNProc;
 	amroutine->amoptsprocnum = SPGIST_OPTIONS_PROC;
diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index dc35b02910..cb74a9cd01 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -937,7 +937,7 @@ copy_table_data(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex, bool verbose,
 	 * tells us it's cheaper.  Otherwise, always indexscan if an index is
 	 * provided, else plain seqscan.
 	 */
-	if (OldIndex != NULL && OldIndex->rd_rel->relam == BTREE_AM_OID)
+	if (OldIndex != NULL && get_amstrategy_am(OldIndex->rd_rel->relam) == BTREE_AM_OID)
 		use_sort = plan_cluster_use_sort(OIDOldHeap, OIDOldIndex);
 	else
 		use_sort = false;
diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index 9ac0383459..b2dd5aad36 100644
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -14,7 +14,7 @@
  */
 #include "postgres.h"
 
-#include "access/genam.h"
+#include "access/amapi.h"
 #include "access/heapam.h"
 #include "access/htup_details.h"
 #include "access/multixact.h"
@@ -869,7 +869,7 @@ is_usable_unique_index(Relation indexRel)
 
 	/*
 	 * Must be unique, valid, immediate, non-partial, and be defined over
-	 * plain user columns (not expressions).  We also require it to be a
+	 * plain user columns (not expressions).  We also require it to be like a
 	 * btree.  Even if we had any other unique index kinds, we'd not know how
 	 * to identify the corresponding equality operator, nor could we be sure
 	 * that the planner could implement the required FULL JOIN with non-btree
@@ -877,7 +877,7 @@ is_usable_unique_index(Relation indexRel)
 	 */
 	if (indexStruct->indisunique &&
 		indexStruct->indimmediate &&
-		indexRel->rd_rel->relam == BTREE_AM_OID &&
+		get_amstrategy_am(indexRel->rd_rel->relam) == BTREE_AM_OID &&
 		indexStruct->indisvalid &&
 		RelationGetIndexPredicate(indexRel) == NIL &&
 		indexStruct->indnatts > 0)
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index 7d176e7b00..9276cd039d 100644
--- a/src/backend/optimizer/path/indxpath.c
+++ b/src/backend/optimizer/path/indxpath.c
@@ -2761,8 +2761,8 @@ match_rowcompare_to_indexcol(PlannerInfo *root,
 	Oid			expr_op;
 	Oid			expr_coll;
 
-	/* Forget it if we're not dealing with a btree index */
-	if (index->relam != BTREE_AM_OID)
+	/* Forget it if we're not dealing with an index like a btree */
+	if (index->strategyam != BTREE_AM_OID)
 		return NULL;
 
 	index_relid = index->rel->relid;
@@ -3459,7 +3459,7 @@ ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
 	 * generate_implied_equalities_for_column; see
 	 * match_eclass_clauses_to_index.
 	 */
-	if (index->relam == BTREE_AM_OID &&
+	if (index->strategyam == BTREE_AM_OID &&
 		!list_member_oid(ec->ec_opfamilies, curFamily))
 		return false;
 
diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c
index 5012bfe142..b6b350bd48 100644
--- a/src/backend/optimizer/util/plancat.c
+++ b/src/backend/optimizer/util/plancat.c
@@ -268,6 +268,7 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
 
 			/* We copy just the fields we need, not all of rd_indam */
 			amroutine = indexRelation->rd_indam;
+			info->strategyam = amroutine->amstrategy_am;
 			info->amcanorderbyop = amroutine->amcanorderbyop;
 			info->amoptionalkey = amroutine->amoptionalkey;
 			info->amsearcharray = amroutine->amsearcharray;
@@ -287,10 +288,10 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
 			/*
 			 * Fetch the ordering information for the index, if any.
 			 */
-			if (info->relam == BTREE_AM_OID)
+			if (info->strategyam == BTREE_AM_OID)
 			{
 				/*
-				 * If it's a btree index, we can use its opfamily OIDs
+				 * If it's like a btree index, we can use its opfamily OIDs
 				 * directly as the sort ordering opfamily OIDs.
 				 */
 				Assert(amroutine->amcanorder);
@@ -317,11 +318,7 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
 				 *
 				 * XXX This method is rather slow and also requires the
 				 * undesirable assumption that the other index AM numbers its
-				 * strategies the same as btree.  It'd be better to have a way
-				 * to explicitly declare the corresponding btree opfamily for
-				 * each opfamily of the other index type.  But given the lack
-				 * of current or foreseeable amcanorder index types, it's not
-				 * worth expending more effort on now.
+				 * strategies the same as btree.
 				 */
 				info->sortopfamily = (Oid *) palloc(sizeof(Oid) * nkeycolumns);
 				info->reverse_sort = (bool *) palloc(sizeof(bool) * nkeycolumns);
@@ -414,7 +411,7 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
 					info->tuples = rel->tuples;
 			}
 
-			if (info->relam == BTREE_AM_OID)
+			if (info->strategyam == BTREE_AM_OID)
 			{
 				/* For btrees, get tree height while we have the index open */
 				info->tree_height = _bt_getrootheight(indexRelation);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index fa1f589fad..2ddb5d5e15 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -5998,8 +5998,8 @@ get_actual_variable_range(PlannerInfo *root, VariableStatData *vardata,
 		IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
 		ScanDirection indexscandir;
 
-		/* Ignore non-btree indexes */
-		if (index->relam != BTREE_AM_OID)
+		/* Ignore indexes that don't behave like btrees */
+		if (index->strategyam != BTREE_AM_OID)
 			continue;
 
 		/*
diff --git a/src/include/access/amapi.h b/src/include/access/amapi.h
index 1dc674d230..e798e2aa66 100644
--- a/src/include/access/amapi.h
+++ b/src/include/access/amapi.h
@@ -207,6 +207,14 @@ typedef struct IndexAmRoutine
 {
 	NodeTag		type;
 
+	/*
+	 * The Oid of the AM that defines the strategies. Typically, this would
+	 * be BTREE_AM_OID for any AM that chooses to use BT StrategyNumbers, etc..
+	 * Or put another way, is it like a btree or a hash index etc..
+	 * This is NOT the Oid of the AM itself.
+	 */
+	Oid			amstrategy_am;
+
 	/*
 	 * Total number of strategies (operators) by which we can traverse/search
 	 * this AM.  Zero if AM does not have a fixed set of strategy assignments.
@@ -286,5 +294,6 @@ typedef struct IndexAmRoutine
 /* Functions in access/index/amapi.c */
 extern IndexAmRoutine *GetIndexAmRoutine(Oid amhandler);
 extern IndexAmRoutine *GetIndexAmRoutineByAmId(Oid amoid, bool noerror);
+extern Oid get_amstrategy_am(Oid indexam_oid);
 
 #endif							/* AMAPI_H */
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index 69ba254372..a257841ca6 100644
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -1068,6 +1068,8 @@ struct IndexOptInfo
 	bool	   *canreturn pg_node_attr(read_write_ignore);
 	/* OID of the access method (in pg_am) */
 	Oid			relam;
+	/* OID of the access method that defines strategies */
+	Oid			strategyam;
 
 	/*
 	 * expressions for non-simple index columns; redundant to print since we