Re: [HACKERS] Regarding GSoc Application - Mailing list pgsql-jdbc

From Andrew Dunstan
Subject Re: [HACKERS] Regarding GSoc Application
Date
Msg-id 4F84480F.1020905@dunslane.net
Whole thread Raw
In response to Re: [HACKERS] Regarding GSoc Application  (Merlin Moncure <mmoncure@gmail.com>)
Responses Re: [HACKERS] Regarding GSoc Application  (Merlin Moncure <mmoncure@gmail.com>)
List pgsql-jdbc

On 04/10/2012 10:34 AM, Merlin Moncure wrote:
> On Tue, Apr 10, 2012 at 9:15 AM, Andrew Dunstan<andrew@dunslane.net>  wrote:
>>
>> On 04/10/2012 09:48 AM, Merlin Moncure wrote:
>>> On Tue, Apr 10, 2012 at 8:42 AM, Andrew Dunstan<andrew@dunslane.net>
>>>   wrote:
>>>>> I am considering two paths for doing this:
>>>>> The first one takes the help of the SPI(Server Programming Interface)
>>>>> and the second one directly connects through Pl/Java and JNI(Java
>>>>> Native Interface).
>>>>>
>>>> I'd say forget SPI - I don't think it's going to help you here. Just
>>>> concentrate on getting the functionality via a PL/Java wrapper. I
>>>> wouldn't
>>>> worry too much about jdbc style URLs either, since logically I think
>>>> you'd
>>>> want to specify the connection parameters via server and FDW options as
>>>> in
>>>> my example above - that way it would be consistent with other FDWs. But
>>>> that's a piece of bikeshedding for now. Basically, you want to implement
>>>> the
>>>> handler function to start with.
>>> how do you cross from FDW into a pl/java routine without SPI?
>>>
>>
>> Add the FDW handler as a sibling function of the function call handler. At
>> least that would be my first approach to writing a DBI::DBD FDW wrapper for
>> plperl, which I naturally know rather better than the PL/Java code.
> right -- well looking at plperl.c, I take it you are meaning to invoke
> (or write a similar function to) the plperl_call_handler, right?  hm
> -- if you could do that then yes, that would work for pl/java as well
> and it would bypass the SPI interface.  this is avoiding the public
> APIs, so it's going to take some time to figure out how to set up the
> call and walk the result since I don't know how to do that off the top
> of my head.
>


I don't understand what the heck you're talking about, TBH. From a user
perspective there is nothing to work out. It will look like any other
FDW. The implementor of the FDW handler will have to work out the glue
between postgres and the JVM, but that's not going to be you, right?

cheers

andrew

pgsql-jdbc by date:

Previous
From: Merlin Moncure
Date:
Subject: Re: [HACKERS] Regarding GSoc Application
Next
From: tsaixingwei
Date:
Subject: Re: Failover Datasource?