diff --git a/src/backend/columnar/columnar_storage.c b/src/backend/columnar/columnar_storage.c
index 7e7f7990b..21aa7ab9c 100644
--- a/src/backend/columnar/columnar_storage.c
+++ b/src/backend/columnar/columnar_storage.c
@@ -169,7 +169,11 @@ ColumnarStorageInit(SMgrRelation srel, uint64 storageId)
 	}
 
 	/* create two pages */
+#if PG_VERSION_NUM >= PG_VERSION_16
+	PGIOAlignedBlock block;
+#else
 	PGAlignedBlock block;
+#endif
 	Page page = block.data;
 
 	/* write metapage */
diff --git a/src/backend/distributed/planner/insert_select_planner.c b/src/backend/distributed/planner/insert_select_planner.c
index f990a06bc..b71d95432 100644
--- a/src/backend/distributed/planner/insert_select_planner.c
+++ b/src/backend/distributed/planner/insert_select_planner.c
@@ -901,15 +901,7 @@ RouterModifyTaskForShardInterval(Query *originalQuery,
 			continue;
 		}
 
-
-		/*
-		 * passing NULL for plannerInfo will be problematic if we have placeholder
-		 * vars. However, it won't be the case here because we are building
-		 * the expression from shard intervals which don't have placeholder vars.
-		 * Note that this is only the case with PG14 as the parameter doesn't exist
-		 * prior to that.
-		 */
-		shardRestrictionList = make_simple_restrictinfo(NULL,
+		shardRestrictionList = make_simple_restrictinfo(restriction->plannerInfo,
 														(Expr *) shardOpExpressions);
 		extendedBaseRestrictInfo = lappend(extendedBaseRestrictInfo,
 										   shardRestrictionList);
diff --git a/src/backend/distributed/planner/relation_restriction_equivalence.c b/src/backend/distributed/planner/relation_restriction_equivalence.c
index b57e37735..af2443b19 100644
--- a/src/backend/distributed/planner/relation_restriction_equivalence.c
+++ b/src/backend/distributed/planner/relation_restriction_equivalence.c
@@ -171,6 +171,8 @@ static bool FindQueryContainingRTEIdentityInternal(Node *node,
 
 static int ParentCountPriorToAppendRel(List *appendRelList, AppendRelInfo *appendRelInfo);
 
+static bool IsVarRelOptOuterJoin(PlannerInfo *root, Var *varToBeAdded);
+
 
 /*
  * AllDistributionKeysInQueryAreEqual returns true if either
@@ -1238,6 +1240,12 @@ AddToAttributeEquivalenceClass(AttributeEquivalenceClass *attributeEquivalenceCl
 		return;
 	}
 
+	/* outer join checks in PG16 */
+	if (IsVarRelOptOuterJoin(root, varToBeAdded))
+	{
+		return;
+	}
+
 	RangeTblEntry *rangeTableEntry = root->simple_rte_array[varToBeAdded->varno];
 	if (rangeTableEntry->rtekind == RTE_RELATION)
 	{
@@ -1379,6 +1387,30 @@ GetTargetSubquery(PlannerInfo *root, RangeTblEntry *rangeTableEntry, Var *varToB
 }
 
 
+/*
+ * IsVarRelOptOuterJoin returns true if the Var to be added
+ * is an outer join, false otherwise.
+ */
+static bool
+IsVarRelOptOuterJoin(PlannerInfo *root, Var *varToBeAdded)
+{
+#if PG_VERSION_NUM >= PG_VERSION_16
+	if (root->simple_rel_array_size <= varToBeAdded->varno)
+	{
+		return true;
+	}
+
+	RelOptInfo *rel = root->simple_rel_array[varToBeAdded->varno];
+	if (rel == NULL)
+	{
+		/* must be an outer join */
+		return true;
+	}
+#endif
+	return false;
+}
+
+
 /*
  * AddUnionAllSetOperationsToAttributeEquivalenceClass recursively iterates on all the
  * append rels, sets the varno's accordingly and adds the
diff --git a/src/backend/distributed/replication/multi_logical_replication.c b/src/backend/distributed/replication/multi_logical_replication.c
index 550095875..c8d0325b6 100644
--- a/src/backend/distributed/replication/multi_logical_replication.c
+++ b/src/backend/distributed/replication/multi_logical_replication.c
@@ -1530,7 +1530,23 @@ CreateSubscriptions(MultiConnection *sourceConnection,
 		appendStringInfo(createSubscriptionCommand,
 						 "CREATE SUBSCRIPTION %s CONNECTION %s PUBLICATION %s "
 						 "WITH (citus_use_authinfo=true, create_slot=false, "
+#if PG_VERSION_NUM >= PG_VERSION_16
+
+		                 /*
+		                  * password_required specifies whether connections to the publisher
+		                  * made as a result of this subscription must use password authentication.
+		                  * However, this setting is ignored when the subscription is owned
+		                  * by a superuser.
+		                  * Given that this command is executed below with superuser
+		                  * ExecuteCriticalRemoteCommand(target->superuserConnection,
+		                  *                              createSubscriptionCommand->data);
+		                  * We are safe to pass password_required as false because
+		                  * it will be ignored anyway
+		                  */
+						 "copy_data=false, enabled=false, slot_name=%s, password_required=false",
+#else
 						 "copy_data=false, enabled=false, slot_name=%s",
+#endif
 						 quote_identifier(target->subscriptionName),
 						 quote_literal_cstr(conninfo->data),
 						 quote_identifier(target->publication->name),
diff --git a/src/test/regress/bin/normalize.sed b/src/test/regress/bin/normalize.sed
index a374c73f5..7bed04edf 100644
--- a/src/test/regress/bin/normalize.sed
+++ b/src/test/regress/bin/normalize.sed
@@ -294,3 +294,12 @@ s/\/\*\{"cId":.*\*\///g
 
 # Notice message that contains current columnar version that makes it harder to bump versions
 s/(NOTICE:  issuing CREATE EXTENSION IF NOT EXISTS citus_columnar WITH SCHEMA  pg_catalog VERSION )"[0-9]+\.[0-9]+-[0-9]+"/\1 "x.y-z"/
+
+# pg16 changes
+# can be removed when dropping PG14&15 support
+#if PG_VERSION_NUM < PG_VERSION_16
+# (This is not preprocessor directive, but a reminder for the developer that will drop PG14&15 support )
+
+s/, password_required=false//g
+
+#endif /* PG_VERSION_NUM < PG_VERSION_16 */