PG Bug reporting form <noreply@postgresql.org> writes:
> We are currently experiencing a problem with DataSet objects that behave
> differently between Oracle and Postgres.
> When we perform "Next Page" / "Previous Page" repeatedly the application
> crashes with a "Duplicate Entry Key" Message on postgres.
It's impossible for anyone to help you on the basis of so little
information. Please read
https://wiki.postgresql.org/wiki/Guide_to_reporting_problems
regards, tom lane