Re: [HACKERS] make async slave to wait for lsn to be replayed

On 22 January 2018 at 23:21, Stephen Frost <sfrost(at)snowman(dot)net> wrote:

>> It sounds reasonable. I can offer the following version.
>>
>> WAIT LSN lsn_number;
>> WAIT LSN lsn_number TIMEOUT delay;
>> WAIT LSN lsn_number INFINITE;
>> WAIT LSN lsn_number NOWAIT;
>>
>>
>> WAIT [token] wait_value [option];
>>
>> token - [LSN, TIME | TIMESTAMP | CSN | XID]
>> option - [TIMEOUT | INFINITE | NOWAIT]
>>
>> Ready to listen to your suggestions.
>
> There were a few different suggestions made, but somehow this thread
> ended up in Needs Review again while still having LSNs. I've changed it
> back to Waiting for Author since it seems pretty unlikely that using LSN
> is going to be acceptable based on the feedback.

I agree with the need for a separate command rather than a function.

I agree that WAIT LSN is good syntax because this allows us to wait
for something else in future.

Without having reviewed the patch, I think we want this feature in PG11.

--
Simon Riggs http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services