Re: [SPAM]Re: Questions about 9.0 release note

Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
> > Tom Lane wrote:
> >> Bruce Momjian <bruce@momjian.us> writes:
> >>> +     Exclusion constraints ensure that if any two rows are compared on
> >>> +     the specified columns or expressions using the specified operators,
> >>> +     at least one of these operator comparisons will be false. The syntax is:
> >>
> >> Isn't that phrasing outright incorrect?  Consider nulls.
>
> > Well, doesn't a comparison returning null really behave as false?
> > Should I reword it as "not true" or "false or null"?
>
> Either one.

I used "false or null".

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com
Index: doc/src/sgml/ddl.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/ddl.sgml,v
retrieving revision 1.91
diff -c -c -r1.91 ddl.sgml
*** doc/src/sgml/ddl.sgml    1 Apr 2010 01:18:17 -0000    1.91
--- doc/src/sgml/ddl.sgml    6 Apr 2010 02:13:57 -0000
***************
*** 861,867 ****
     <para>
      Exclusion constraints ensure that if any two rows are compared on
      the specified columns or expressions using the specified operators,
!     at least one of these operator comparisons will be false. The syntax is:
  <programlisting>
  CREATE TABLE circles (
      c circle,
--- 861,868 ----
     <para>
      Exclusion constraints ensure that if any two rows are compared on
      the specified columns or expressions using the specified operators,
!     at least one of these operator comparisons will return false or null.
!     The syntax is:
  <programlisting>
  CREATE TABLE circles (
      c circle,