TT
CLASS="LITERAL"
>FROM</TT
> <TT
CLASS="REPLACEABLE"
><I
>old_version</I
></TT
> option, which causes it to not run the
     normal installation script for the target version, but instead the update
     script named
     <TT
CLASS="LITERAL"
><TT
CLASS="REPLACEABLE"
><I
>extension</I
></TT
>--<TT
CLASS="REPLACEABLE"
><I
>old_version</I
></TT
>--<TT
CLASS="REPLACEABLE"
><I
>target_version</I
></TT
>.sql</TT
>.
     The choice of the dummy version name to use as <TT
CLASS="REPLACEABLE"
><I
>old_version</I
>