Re: wat is the max number of rows that can be returned

On Wed, 2002-12-04 at 10:55, Tom Lane wrote:
> Joel Burton <joel@joelburton.com> writes:
> > And you're wondering what will happen if you write a query that returns
> > more than 2 billion rows (2000 million)?
>
> The first thing that will happen is that you'll run out of memory in the
> client process to store all those rows in your PGresult.
>
> You can handle ridiculously-large query results by opening a cursor
> and fetching reasonable-sized chunks with FETCH; it might take awhile
> but in theory you could process an indefinitely large result that way.
>
> I don't think the int-sized result of PGntuples is going to be a issue
> in the foreseeable future --- platforms that could hold >2G tuples are
> no doubt going to use a wider size of int.

Besides, at 100ns per insert, it would take 33,000 years to populate
the table...

Also, those 9.2x10^18 records at 8 bytes each would need 7.3x10^19
bytes.  And that's not even considering that each record will be
considerably larger that just the 8 bytes.

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