Collectors versus Flow.Subscriber

[Douglas Surber]

If it is a row sequence then a RowProcessorOperation should be exactly what you need.

Douglas

> On May 1, 2018, at 4:09 AM, Alexander Kjäll <alexander.kjall at gmail.com> wrote:
> 
> It can maybe be thought of as an row sequence with one row per event, and
> it should be possible to be represented as a RowOperation.
> 
> But I was more thinking about back pressure, the collector interface
> doesn't really allow the implementation to signal to the driver that it
> can't handle the rate of traffic, and a busy event generator might
> overwhelm the consumer. This might maybe be a problem with normal queries
> also?
> 
> I haven't done any testing of this, and I don't have any concrete code that
> demonstrates the problem. I can revisit this topic later when I have
> something more concrete to show and talk about.
> 
> best regards
> Alexander Kjäll
> 
> Den mån 30 apr. 2018 kl 18:06 skrev Douglas Surber <
> douglas.surber at oracle.com>:
> 
>> We haven’t discussed much aside from ANSI SQL. I don’t know anything
> about postgresql logical decoding. Is it a row sequence? If so then either
> RowOperation or RowProcessorOperation should do fine. If it returns a
> result that doesn’t map to an ANSI SQL result then it would require a
> vendor specific extension.
> 
>> Douglas
> 
>>> On Apr 28, 2018, at 1:21 PM, Alexander Kjäll <alexander.kjall at gmail.com>
> wrote:
>>> 
>>> Hi
>>> 
>>> I have been poking around writing an implementation of ADBA for
> postgresql
>>> and have a question regarding how 'endless' datastreams should be
> handled.
>>> 
>>> To take a concrete case is the feature in postgresql that's called
> logical
>>> decoding, it lets a user subscribe to the replication stream from the
>>> database.
>>> 
>>> This isn't a stream that has an end, and by that account it doesn't
> really
>>> in the stream model with collectors and would maybe fit better with the
>>> Flow.Subscriber model.
>>> 
>>> Have this usecase been considered and is there a way to implement this
> that
>>> I haven't seen?
>>> 
>>> best regards
>>> Alexander Kjäll