Re: [GENERAL] Retrieving query results - Mailing list pgsql-general

From Igor Korot
Subject Re: [GENERAL] Retrieving query results
Date
Msg-id CA+FnnTwyUpQG4z06mhYnES65Wt+3+L6Ke8S=jbPGRZS85=tOLQ@mail.gmail.com
Whole thread Raw
In response to Re: [GENERAL] Retrieving query results  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
Hi,

On Thu, Aug 24, 2017 at 7:18 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Igor Korot <ikorot01@gmail.com> writes:
>> So there is no way to retrieve an arbitrary number of rows from the query?
>> That sucks...
>
> The restriction is on the number of rows in one PGresult, not the total
> size of the query result.  You could use single-row mode, or use a cursor
> and fetch some reasonable number of rows at a time.  If you try to inhale
> all of a many-gigarow result at once, you're going to have OOM problems
> anyway, even if you had the patience to wait for it.  So I don't think the
> existence of a limit is a problem.  Failure to check it *is* a problem,
> certainly.

Is there a sample of using single-row mode?
How to turn it on and turn it off?

Is there a cursor example with the Prepared Statements?
The one in the documentation doesn't use them - it uses PQexec().

Thank you.

>
>                         regards, tom lane


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