Does the initial postgres user have a password?

I have a new 9.5 installation, Windows x64, developer only. No users have been added, and no passwords set.

I can access the system:

·         using pgAdmin3, without specifying a user or password

·         using psql, specifying user ‘postgres’ but no password

I cannot access the system with various other tools that require a connection string eg

password authentication failed for user "postgres"

There is a ‘postgres’ user defined in pg_shadow with password of : "md5a19959576d12fc69375fc3dadaeab90b"

What is going on here? Is there a password for user ‘postgres’ or isn’t there? What is it? Why don’t I need it sometimes, and I do other times?

Regards

David M Bennett FACS

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