Re: Out of memory while reading tuples

Hi Markus,

On 2018/11/06 7:34, Markus Angst wrote:
> Hi,
>
> Postgres 10.4 64bit on Windows
> psqlODBC 10.03.0000
> - Use Declare/Fetch is off
> - Cache size is 10'000'000
>
> Issuing a simple select statement with Microsoft Access gives me the 
> following ODBC error:
>
> "Out of memory while reading tuples.; memory allocation error??? (#4)"
>
> The statement returns 822701 rows (via JDBC), average row size is 100 
> bytes.
>
> On https://odbc.postgresql.org/docs/config.html it says:
> "Cache Size: When using cursors, this is the row size of the tuple 
> cache. If not using cursors, this is how many tuples to allocate 
> memory for at any given time. The default is 100 rows for either case."

Hmm, it seems a documentation bug to me.

   "If not using cursors, this is how many tuples to allocate memory at 
first."

seems correct.
So "Cache size" doesn't have much meaning if *Use Declare/Fetch* is off.
I think there's no way to avoid *Out of memory while reading tuples* errors
in *Use Declare/Fetch* off mode unfortunately.

regards,
Hiroshi inoue

>
>
> Setting the field to the aforementioned 10'000'000 does not help. Is 
> this value ignored? Is there a maximum value for Cache size? How is 
> the tuple size calculated?
>
> Setting Use Declare/Fetch is not an option. Access can have severe 
> problems with this setting; an experience I don't want to repeat.
>
> My plan B would be to select the data in several pieces, which would 
> be much more complicated in this particular case.
>
> What else can I do?
>
> Thanks and best regards
> Markus Angst