Re: Enhance 'pg_createsubscriber' to retrieve databases automatically when no database is provided.

On Mon, 10 Feb 2025 at 20:36, Shubham Khanna
<khannashubham1197@gmail.com> wrote:
>
> The attached patch contains the suggested changes.

If a new database is created on the primary server while
pg_createsubscriber is running, the subscription will not be created
for the new database.
To reproduce this issue, follow these steps:
Debug pg_createsubscriber and set a breakpoint after the
fetch_source_databases function, where the databases would have been
prepared.
While execution of pg_createsubscriber is paused, create a new
database on the primary node.
You will observe that the database is created on the standby node, but
the subscription will not be created for the newly created database.
+fetch_source_databases(struct CreateSubscriberOptions *opt)
+{
+       PGconn     *conn;
+       PGresult   *res;
+       int                     num_rows;
+
+       /* Establish a connection to the PostgreSQL server */
+       conn = connect_database(opt->pub_conninfo_str, true);
+
+       res = PQexec(conn, "SELECT datname FROM pg_database WHERE
datistemplate = false AND datallowconn = true");
+
+       /* Check for errors during query execution */
+       if (PQresultStatus(res) != PGRES_TUPLES_OK)

Regards,
Vignesh