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

Dear Shveta,

Thanks for reviewing! PSA new version.

> 1.
> + errmsg("min_apply_delay must not be set when streaming = parallel")));
> we give the same error msg for both the cases:
> a. when subscription is created with streaming=parallel but we are
> trying to alter subscription to set min_apply_delay >0
> b. when subscription is created with some min_apply_delay and we are
> trying to alter subscription to make it streaming=parallel.
> For case a, error msg looks fine but for case b, I think error msg
> should be changed slightly.
> ALTER SUBSCRIPTION regress_testsub SET (streaming = parallel);
> ERROR: min_apply_delay must not be set when streaming = parallel
> This gives the feeling that we are trying to modify min_apply_delay
> but we are not. Maybe we can change it to:
> "subscription with min_apply_delay must not be allowed to stream
> parallel" (or something better)

Your point that error messages are strange is right. And while
checking other ones, I found they have very similar styles. Therefore I reworded
ERROR messages in AlterSubscription() and parse_subscription_options() to follow
them. Which version is better?

Best Regards,
Hayato Kuroda
FUJITSU LIMITED