Cheers for the pointers. Am i right in thinking that if i get an array of
arrays, the nested arrays are sent in wire format as well - it seems to be
from the docs.
Secondly, comments are a bit scarse in the code, but am i also right in
thinking that an array indexing can start at an arbitrary value? This seems
to be what the lbound value is for... or is this a addition to deal with
nulls eg, {null, null, null, 4} would have a lbound of 3.... (or both)
Thanks
----- Original Message -----
From: "Andrew Chernow" <a...@esilo.com>
To: "John Lister" <john.lister...@kickstone.com>
Cc: <pgsql-hackers@postgresql.org>
Sent: Wednesday, April 08, 2009 4:07 PM
Subject: Re: [HACKERS] Array types
Andrew Chernow wrote:
John Lister wrote:
Following this up, is there any docs on the binary wire format for
arrays?
None that I know of.
Check out the backend source: (array_recv() and array_send() functions)
http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/arrayfuncs.c?rev=1.154
Or, look at libpqtypes array.c:
http://libpqtypes.esilo.com/browse_source.html?file=array.c
Forgot to mention, this is not as simple as understanding the array
format. You have to understand the wire format for all types that can be
array elements. The array wire format serializes its array elements as
[elem_len][elem_data]. elem_data is the wire format of the array element
type, like an int, timestamp, polygon, bytea, etc... So once you unravel
the array container format, you still have to demarshal the type data.
--
Andrew Chernow
eSilo, LLC
every bit counts
http://www.esilo.com/
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