Re: java.lang.OutOfMemoryError: GC overhead limit exceeded

On 7/23/20 8:33 AM, Christophe combet wrote:
> Dear Rob,
> 
> Total RAM is 512GB.
> 
> Runtime.getRuntime().freeMemory() says: 7,630,918,904 at the time of 
> issuing the query.
> 
> jConsole timed out and it is impossible to reconnect. I did a screen 
> capture at the time of the freeze.
> 
> Le jeudi 23 juillet 2020 à 15:33:34 UTC+2, Rob Sargent 
> <robjsargent@gmail.com> a écrit :
> 
> 
> 
> 
> On 7/23/20 6:30 AM, Christophe combet wrote:
>  >
>  > Thank you for pointing the link between auto commit an buffering.
>  >
>  > autocommit=false: same exception.
>  >
>  > We try fetchSize.
>  >
>  > Thanks.
>  > Le jeudi 23 juillet 2020 à 13:47:14 UTC+2, Vladimir Sitnikov
>  > <sitnikov.vladimir@gmail.com <mailto:sitnikov.vladimir@gmail.com>> a 
> écrit :
>  >
>  >
>  >  >can you try switching to autocommit=false?
>  >
>  > + you probably need to configure fetchSize as well.
>  >
>  > Vladimir
> 
>  >
> You set the 8G limit on the java process but did you tell up the
> available RAM?  This query would require that about 3G be available to
> hold all the data. Can you use jConsole to establish how much memory is
> available at the time of issuing the query?
> 
> 
> 
Upthread the select statement returned only "column1"
* We are doing a "SELECT column1 FROM table1 ODER BY column1;" (column1 
* is   varchar(14) and the table contains 130,080,790 rows), when the * 
* exception occurs.
Are you reading in the bytea column as well?

And does it finish if you add more memory to the jvm (just for testing 
purposes).