Re: [PATCHES] libpq type system 0.9a - Mailing list pgsql-hackers

From Andrew Chernow
Subject Re: [PATCHES] libpq type system 0.9a
Date
Msg-id 47FCB7FF.3000204@esilo.com
Whole thread Raw
In response to Re: [PATCHES] libpq type system 0.9a  ("Merlin Moncure" <mmoncure@gmail.com>)
Responses Re: [PATCHES] libpq type system 0.9a  (Andrew Chernow <ac@esilo.com>)
List pgsql-hackers
Merlin Moncure wrote:
> On Wed, Apr 9, 2008 at 8:04 AM, Andrew Dunstan <andrew@dunslane.net> wrote:
> \>  Merlin Moncure wrote:
>>> However, due to libpq limitations, if any datatype must
>>> return text the entire result must be text (resultFormat)...this is
>>> also interestingly true for functions that return 'void'.  So, at
>>> present, to use PQgetf, you result set must be binary.
>>  I'm surprised you didn't try to address that limitation.
> 
> 
> whoops! we did...thinko on my part.  Text results are fully supported
> save for composites and arrays.
> 
> merlin
> 

Yeah, currently composites and arrays only support binary results in libpqtypes.   This forces any array elementType or
anymember of a composite to have a 
 
send/recv routine.  Using the "fallback to text output" approach, this 
limitation on array elements and composite members would be removed.
>>That makes it sound more like a protocol limitation, rather than a>>libpq limitation. Or am I misunderstanding?
It looks like libpq, message 'T' handling in getRowDescriptions, reads a 
separate format for each column off the wire.  The protocol already has this 
ability.  The backend needs a ?minor? adjustment to make use of the existing 
capability.

-- 
Andrew Chernow
eSilo, LLC
every bit counts
http://www.esilo.com/


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