Yuriy>1. In PgConnection.java, the autocommit is initially set to true in the declaration (private boolean autocommit = true). In the constructor of the PgConnection class, several options are checked (PGProperty), but there is none that has to do with autocommit. Thus, unless, the client explicitely calls setAutoCommit(false), it will remain true.
Just for the reference, the specification (see Connection#setAutoCommit javadoc) states that "By default, new connections are in auto-commit mode"