Re: PQntuples returns an int. - Mailing list pgsql-general

From Steve Atkins
Subject Re: PQntuples returns an int.
Date
Msg-id AD4CD5A6-3285-4691-9A0C-9F9E8EFB2007@blighty.com
Whole thread Raw
In response to PQntuples returns an int.  (Guillaume Yziquel <guillaume.yziquel@citycable.ch>)
List pgsql-general
On Mar 3, 2010, at 10:05 AM, Guillaume Yziquel wrote:

> Hello.
>
> I've been looking at the PQntuples function, in section 29.3.2. 'Retrieving query result information' of
>
>     http://www.postgresql.org/docs/8.2/interactive/libpq-exec.html
>
> The declaration is:
>
>> int PQntuples(const PGresult *res);
>
> I'm wondering: why the 'int'? why not a 'long int', or an 'unsigned int', or whatever?
>
> I'm asking this because I'm wondering whether you could have more tuples in the result of a query than could be
indexedby the 'int' type. May this happen? 

That's returning the number of tuples you've already retrieved and have in memory on the client.

I'm not sure what the overhead in storage is, but if you have more than two billion tuples in your result set you're
probablygoing to blow out of memory long before you get there (and should be using a cursor instead). 

Cheers,
  Steve


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