>Sergey,
>
>one last question (for now), in my openquery I want to do a test on a character field:
>select * from openquery(ls,'select * from table where field='CHAR'')
>How can I do this correctly ? SQL returns an error because of the double quotes.

You double single quotes iside the string literal.

select * from openquery(ls,
      'select * from table where field=''CHAR''')