Re: [PATCH] Use indexes on the subscriber when REPLICA IDENTITY is full on the publisher

```
+       /* Build scankey for every non-expression attribute in the index. */
```

I think that single line comments should not terminated by ".".

```
+       /* There should always be at least one attribute for the index scan. */
```

Same as above.

```
+#ifdef USE_ASSERT_CHECKING
+                       IndexInfo  *indexInfo = BuildIndexInfo(idxrel);
+
+                       Assert(!IsIndexOnlyOnExpression(indexInfo));
+#endif
```

I may misunderstand, but the condition of usable index has alteady been checked
when the oid was set but anyway the you confirmed the condition again before
really using that, right?
So is it OK not to check another assumption that the index is b-tree, non-partial,
and one column reference?

IIUC we can do that by adding new function like IsIndexUsableForReplicaIdentityFull()
that checks these condition, and then call at RelationFindReplTupleByIndex() if
idxIsRelationIdentityOrPK is false.

032_subscribe_use_index.pl

```
+# Testcase start: SUBSCRIPTION CREATE/DROP INDEX WORKS WITHOUT ISSUES
...
+# Testcase end: SUBSCRIPTION RE-CALCULATES INDEX AFTER CREATE/DROP INDEX
```

There is still non-consistent case.

Anyway, I see your point, so
if you want to keep the naming as you proposed at least don't change
the ordering for get_opclass_input_type() call because that looks odd
to me.