ackaging modification
    scripts that adjust the definitions of the SQL objects contained in an
    extension.  For example, if version 1.1 of an extension adds one function
    and changes the body of another function compared to 1.0, the extension
    author can provide an <I
CLASS="FIRSTTERM"
>update script</I
> that makes just those
    two changes.  The <TT
CLASS="COMMAND"
>ALTER EXTENSION UPDATE</TT
> command can then
    be used to apply these changes and track which version of the extension
    is 