Re: speed up a logical replica setup

Few comments:

1)   Can we use strdup here instead of atoi, as we do similarly in

case of pg_dump too, else we will do double conversion, convert using

atoi and again to string while forming the connection string:

+                       case 'p':

+                               if ((opt.sub_port = atoi(optarg)) <= 0)

+                                       pg_fatal("invalid subscriber

port number");

+                               break;

2) We can have some valid range for this, else we will end up in some

unexpected values when a higher number is specified:

+                       case 't':

+                               opt.recovery_timeout = atoi(optarg);

+                               break;

3) Now that we have addressed most of the items, can we handle this TODO:

+               /*

+                * TODO use primary_conninfo (if available) from subscriber and

+                * extract publisher connection string. Assume that there are

+                * identical entries for physical and logical

replication. If there is

+                * not, we would fail anyway.

+                */

+               pg_log_error("no publisher connection string specified");

+               pg_log_error_hint("Try \"%s --help\" for more

information.", progname);

+               exit(1);

4)  By default the log level as info here, I was not sure how to set

it to debug level to get these error messages:

+               pg_log_debug("publisher(%d): connection string: %s",

i, dbinfo[i].pubconninfo);

+               pg_log_debug("subscriber(%d): connection string: %s",

i, dbinfo[i].subconninfo);

5) Currently in non verbose mode there are no messages printed on

console, we could have a few of them printed irrespective of verbose

or not like the following:

a) creating publication

b) creating replication slot

c) waiting for the target server to reach the consistent state

d) If pg_createsubscriber fails after this point, you must recreate

the physical replica before continuing.

e) creating subscription

6) The message should be "waiting for the target server to reach the

consistent state":

+#define NUM_CONN_ATTEMPTS      5

+

+       pg_log_info("waiting the target server to reach the consistent state");

+

+       conn = connect_database(conninfo, true);