Text from the user manual (see link)
Gets or sets the string used to connect to a PostgreSQL database.
/// Valid values are:
/// Server: Address/Name of Postgresql Server;
/// Port: Port to connect to;
/// Protocol: Protocol version to use, instead of automatic; Integer 2 or 3;
/// Database: Database name. Defaults to user name if not specified;
/// User Id: User name;
/// Password: Password for clear text authentication;
/// SSL: True or False. Controls whether to attempt a secure connection. Default = False;
/// Pooling: True or False. Controls whether connection pooling is used. Default = True;
/// MinPoolSize: Min size of connection pool. Default: 1;
/// MaxPoolSize: Max size of connection pool. Default: 20;
/// Encoding: Encoding to be used; Can be ASCII or UNICODE. Default is ASCII. Use UNICODE if you are having problems with accents.
/// Timeout: Time to wait for connection open in seconds. Default is 15.
/// CommandTimeout: Time to wait for command to finish execution before throw an exception. In seconds. Default is 20.
/// Sslmode: Mode for ssl connection control.
/// ConnectionLifeTime: Time to wait before closing unused connections in the pool in seconds. Default is 15.
/// SyncNotification: Specifies if Npgsql should use synchronous notifications
Encoding can be ASCII or UNICODE. If your application uses characters with accents and with default settings it doesn't work, try changing that.
Min pool size when specified will make NpgsqlConnection pre allocates this number of connections with the server.
Sslmode can be one of the following values:
Prefer - If it is possible to connect using ssl, it will be used.
Require - If an ssl connection cannot be made, an exception is thrown.
Allow - Not supported yet, just connects without ssl.
Disable - No ssl connection is done.
Default is Disable.
Example:
Server=192.168.10.4;Port=5432;Userid=postgres;Password=stefan;Protocol=3;SSL=false;Pooling=true;MinPoolSize=1;MaxPoolSize=20;Encoding=UNICODE;Timeout=15;SslMode=Disable;Database=test
