• Should improve performance by avoiding creating unnecessary transactions
• In commit mode, also removes the need to auto-rollback failed queries

In sql.py: DbConn._db(): Configure connection, replace¹:

            # Record that a transaction is already open
            self._savepoint += 1

            # Configure connection
            if hasattr(self.db, 'set_isolation_level'):
                import psycopg2.extensions
                self.db.set_isolation_level(
                    psycopg2.extensions.ISOLATION_LEVEL_READ_COMMITTED)

            # Record that a transaction is already open
            if not self.autocommit: self._savepoint += 1

            # Configure connection

            # Set autocommit mode
            if self.autocommit:
                if hasattr(self.db, 'set_isolation_level'):
                    import psycopg2.extensions
                    self.db.set_isolation_level(
                        psycopg2.extensions.ISOLATION_LEVEL_AUTOCOMMIT)
                elif hasattr(self.db, 'autocommit'): self.db.autocommit(1)

In sql.py: DbConn.close(): Record that the automatic transaction is now closed, replace¹:

        self._savepoint -= 1

        if not self.autocommit: self._savepoint -= 1

¹ r3689