Change language of system and error messages in PostgreSQL

SET lc_messages TO 'en_US.UTF-8';

More info on requirements and limitations here.

For me neither Milen A. Radev's nor user1's answer worked - editing PostgreSQL\11\data\postgresql.conf had absolutely no effect. Even after setting lc_messages = 'random value' PostgreSQL would still start.

What helped was to delete PostgreSQL\11\share\locale\*\LC_MESSAGES, after that I finally got English messages.

In my case (on Windows Server 2019) I managed to change language by creating a system environment variable "LC_MESSAGES" with value "English":

setx LC_MESSAGES English /m

(Solution taken from here)

I've reproduced the same issue with naming of PostgreSQL error messages which were specifically displayed in Intellij IDEA similar to:

the only solution for me was renaming C:\Program Files\PostgreSQL\13\share\locale folder to another default name.

then as result changed to:

To be noticed: it wasn't related to Intellij Idea configurations at all, because I tested different answers (and other non-related to IDE answers), e.g., like:

1. Help | Edit custom VM options
2. Setting of Environments variables
3. Using specific commands

only change postgresql.conf is not working on windows10，the following method is fine for me，is very simple but work:

1. change lc_message = en_US.UTF-8, in postgresql.conf;
2. delete all files in fold: \share\locale, expect es fold or the language you want to keep;
3. restart pg service and then you will find that is what you want!