Re: Passing current_database to BackgroundWorkerInitializeConnection

On Mon, Apr 2, 2018 at 2:27 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:

> Hi,
>
> On 2018-04-02 14:24:53 -0500, Jeremy Finzel wrote:
> > Thank you, this makes sense. However, how can this be done since I can
> > only pass one argument to bgw_main? Is there any way to do this without
> > having to store the value in shared memory?
>
> No (I mean you can store it in the filesystem or such as well, but
> ...). Pretty fundamentally sharing data between concurrently running
> processes needs a medium to share the data over. The bgw infrastructure
> allocates just enough so you can put an index to it into
> shmem. Allocating more would be wasteful and/or not enough for some
> users.
>
> Greetings,
>
> Andres Freund
>

Hmmm... not sure if I follow. My goal is to run a SQL statement every 10
seconds (or what value is chosen) in a particular database, using a
background worker. Those are the two arguments. Am I missing some way to
implement this apart from passing those 2 arguments into the launcher
function? Is the way to do this properly then to allocate shared memory
for it, as opposed to trying to pass args into the main function?

Thanks,
Jeremy