RE: Time delayed LR (WAS Re: logical replication restrictions)

Dear Amit,

Thank you for commenting!

> > 8.
> > + <para>
> > + The delay is effective only when the initial table synchronization
> > + has been finished and the publisher decides to send a particular
> > + transaction downstream. The delay does not take into account the
> > + overhead of time spent in transferring the transaction, which
> means
> > + that the arrival time at the subscriber may be delayed more than
> the
> > + given time.
> > + </para>
> >
> > I'm not sure about this mention about only "effective only when the
> > initial table synchronization has been finished"... Now that the delay
> > is pub-side I don't know that it is true anymore.
> >
>
> This will still be true because we don't wait during the initial copy
> (sync). The delay happens only when the replication starts.

Maybe this depends on the definition of initial copy and sync.
I checked and added descriptions in [1].

> > 11.
> > + errno = 0;
> > + parsed = strtoul(strVal(defel->arg), &endptr, 10);
> > + if (errno != 0 || *endptr != '\0')
> > + ereport(ERROR,
> > + (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
> > + errmsg("invalid min_send_delay")));
> > +
> > + if (parsed > PG_INT32_MAX)
> > + ereport(ERROR,
> > + (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
> > + errmsg("min_send_delay \"%s\" out of range",
> > + strVal(defel->arg))));
> >
> > Should the validation be also checking/asserting no negative numbers,
> > or actually should the min_send_delay be defined as a uint32 in the
> > first place?
> >
>
> I don't see the need to change the datatype of min_send_delay as
> compared to what we have min_apply_delay.

I think it is OK to change "long" to "unsinged long", because
We use strtoul() for reading and should reject the minus value.
Of course we can modify them, but I want to keep the consistency with proto_version part.

[1]: https://www.postgresql.org/message-id/TYAPR01MB5866C6BCA4D9386D9C486033F5A59@TYAPR01MB5866.jpnprd01.prod.outlook.com

Best Regards,
Hayato Kuroda
FUJITSU LIMITED