Re:

Dave and Andre, thank for your responses!

The JDBC driver needs the Primary Key in Select query to identify the row.
I was mistaken thinking of  doing without it,

ResultSet makes updates in Row  executing the

java.sql.Connection.prepareStatement("UPDATE holidays SET  "g_name" = ?
WHERE "id" = ?")
and  executeUpdate()

when user makes call ResultSet.updateRow() and "id" - the Primary Key in
database's table.  It's logicaly for me now....

The same is going on whe users call ResultSet.insertRow().
The only question presents, why the JDBCDriver developers want to find
PrimaryKey or oid field inside method "moveToInsertRow()"?
I think it mustn't be JDBCDriver problem.
It is the Postrgre server trouble or developers who use JDBCDriver.

I'm going to do in way Andre has recommended and use id field in SELECT
query as Dave has advised.

Thank!