Skip site navigation (1) Skip section navigation (2)

Re: Re: [Oledb-dev] double precision error with pg linux server, but not with windows pg server

From: Shachar Shemesh <shachar(at)shemesh(dot)biz>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Julian Heeb <heebj2000(at)yahoo(dot)de>, oledb-devel(at)pgfoundry(dot)org, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Re: [Oledb-dev] double precision error with pg linux server, but not with windows pg server
Date: 2007-05-19 18:16:08
Message-ID: 464F3EE8.9070608@shemesh.biz (view raw or flat)
Thread:
Lists: pgsql-hackers
Tom Lane wrote:
> Shachar Shemesh <shachar(at)shemesh(dot)biz> writes:
>   
>> I've received a bug report on the OLE DB list, which I suspect is
>> actually a server bug. The correspondence so far is listed further on,
>> but, in a nutshell, user runs an OLE DB client on windows (OLE DB uses
>> the binary interface), and server version 8.1.9 on Windows, and all is
>> fine. When the server is switched to 8.1.8 on Debian Etch on ARM9,
>> float8 type is not received properly by OLE DB.
>>     
>
> Perhaps OLE is trying to use binary instead of text transmission of
> data?
Of course it does. That's what the OLE DB specs say. Said so in my
original email.
>   It's not a server bug if ARM has a different FP format than
> the client hardware;
No. The server can use, internally, whatever it wants.
>  it's the client's responsibility to either use
> text format or be prepared to cope with whatever the binary format is.
>   
I agree 100%.

I'll reiterate - the problem is not that PG is exporting the internal
ARM FP format. The problem is that the server is exporting the internal
ARM FP format when the server is ARM, and the IEEE format when the
server is Intel. It's not the format, it's the inconsistency.

I can (and I do) handle, in PgOleDb, binary format that are vastly
different than those that I need (anyone said "timestamps"?). Handling a
format that is inconsistent across same version backends merely because
of platform, now that's a server bug if I ever saw one.
> 			regards, tom lane
>   
Like I said elsewhere, I'm willing to write a patch to "pq_sendfloat8"
(and probably "pq_getmsgfloat8" too) to make sure it does the conversion
on ARM platforms. Hell, I think I can even write it portable enough so
that it will work on all non-IEEE platforms (I'm not sure yet, but I
have a general idea). What I'm hoping for, however, is that if I do, you
(or another comitter) will get it in.

Shachar


In response to

Responses

pgsql-hackers by date

Next:From: Heikki LinnakangasDate: 2007-05-19 18:25:16
Subject: Re: Maintaining cluster order on insert
Previous:From: Shachar ShemeshDate: 2007-05-19 18:04:39
Subject: Re: Re: [Oledb-dev] double precision error with pg linux server, but not with windows pg server

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group