RE: Logical Replication of sequences

Dear Hou,

Thanks for updating the patch. Here are comments for recent 0002.
Others are still being reviewed

01. pg_subscription_rel.h
```
+#include "nodes/primnodes.h"
```

The inclusion is not needed because the 


02. typedefs.list
```
+SubscriptionRelKind
```

Missing update.

03. subscritioncmds.c
```
+#include "catalog/pg_sequence.h"
```

I could build without the inclusion. Can you remove?

04. check_publications_origin
```
+
+       query = "SELECT DISTINCT P.pubname AS pubname\n"
+                       "FROM pg_publication P,\n"
+                       "     LATERAL %s GPR\n"
...
```

pgindent does not like the notation. How aboout chaning the line after the "="?
I.e.,

```
    query =
        "SELECT DISTINCT P.pubname AS pubname\n"
        "FROM pg_publication P,\n"
        "     LATERAL %s GPR\n"
...
```

05. AddSubscriptionRelState

```
    if (HeapTupleIsValid(tup))
        elog(ERROR, "subscription table %u in subscription %u already exists",
             relid, subid);
```

Theoretically subid might be the sequence, right? Should we say "relation"
instead of "table" as well?

06. AlterSubscription_refresh_seq
```
+               /* Get local relation list. */
```

In contrast can we say "sequence"?


07. check_publications_origin
```
    if (res->status != WALRCV_OK_TUPLES)
        ereport(ERROR,
                (errcode(ERRCODE_CONNECTION_FAILURE),
                 errmsg("could not receive list of replicated tables from the publisher: %s",
                        res->err)));
```

Should we say "relations" instead of "tables"? Similar lines are:

```
    /* Process tables. */
...
     * Log a warning if the publisher has subscribed to the same table from
```

Best regards,
Hayato Kuroda
FUJITSU LIMITED