Very respectfully to you, stefby, “I’m not so sure that you’re correct on this.
When I read section 23.3.3 of this PostGres doc page, it states that automatic conversion between client and server datasets is provided, and UTF8<->WIN is a supported combination.
What I am suspicious of is that Perl is treating the data as UTF8, within Data::Dumper. It should be easy to query the database directly to be sure that the characters were stored (translated) correctly, and that the received characters are in CP1251. I suspect that Perl thinks that it’s dealing with UTF8.