Re: PQntuples return type

From: Bruce Momjian <bruce(at)momjian(dot)us>
To: Greg Sabino Mullane <greg(at)turnstep(dot)com>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: PQntuples return type
Date: 2007-09-26 08:45:54
Message-ID: 200709260845.l8Q8jsv15466@momjian.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

Greg Sabino Mullane wrote:
> > So, my doubt is: if the return type is int instead of unsigned int,
> > is this function testable for negative return values?
>
> A quick glance at the code in fe-exec.c and fe-protocol3.c shows that
> the underlying variable starts at 0 as an int and in incremented by
> one every row, so it seems possible that it could wrap around for
> very large results sets and/or boxes with a low representation of 'int'.
> There may be some other safeguards in place I did not see to prevent this,
> but I don't see a reason why we shouldn't use unsigned int or
> unsigned long int here, both for ntups and the return value of the
> function.

On second thought, I have at least updated the function documentation:

Returns the number of rows (tuples) in the query result. Because
it returns an integer result, large result sets might overflow the
return value on 32-bit operating systems.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://www.enterprisedb.com

+ If your life is a hard drive, Christ can be your backup. +

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Romain Roure 2007-09-26 08:51:43 Duplicate public schema and user tables
Previous Message Bruce Momjian 2007-09-26 08:42:07 Re: PQntuples return type