o the Tcl interpreter immediately before the first
        execution of a PL/Tcl function in a database session.  (This
        happens separately for each Tcl interpreter, if more than one is
        used in a session; see <A
HREF="pltcl-global.html"
>Section 41.4</A
>.)
       </P
><P
>        While the <TT
CLASS="LITERAL"
>unknown</TT
> module could actually contain any
        initialization script you need, it normally defines a Tcl
        <CODE
CLASS="FUNCTION"
>unknown</CODE
> procedure that is invo