Обсуждение: BUG #6016: Documentation makes inappropriate reference to boolean logic

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BUG #6016: Documentation makes inappropriate reference to boolean logic

От
""
Дата:
The following bug has been logged online:

Bug reference:      6016
Logged by:
Email address:      asuffield@acunu.com
PostgreSQL version: 9 (all)
Operating system:   documentation
Description:        Documentation makes inappropriate reference to boolean
logic
Details:

Documentation section 9.1 reads:

"SQL uses a three-valued Boolean logic..."

A "Boolean logic" is a specific thing, and all Boolean logics have 2^k
values; a 3-valued logic is not Boolean. Should read:

"The SQL Boolean type uses a three-valued logic..."

(Curiously, SQL99 appears to be an actual 4-valued Boolean logic)

Re: BUG #6016: Documentation makes inappropriate reference to boolean logic

От
Bruce Momjian
Дата:
asuffield@acunu.com wrote:
>
> The following bug has been logged online:
>
> Bug reference:      6016
> Logged by:
> Email address:      asuffield@acunu.com
> PostgreSQL version: 9 (all)
> Operating system:   documentation
> Description:        Documentation makes inappropriate reference to boolean
> logic
> Details:
>
> Documentation section 9.1 reads:
>
> "SQL uses a three-valued Boolean logic..."
>
> A "Boolean logic" is a specific thing, and all Boolean logics have 2^k
> values; a 3-valued logic is not Boolean. Should read:
>
> "The SQL Boolean type uses a three-valued logic..."
>
> (Curiously, SQL99 appears to be an actual 4-valued Boolean logic)

Attached patch applied to HEAD and 9.0.X.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
new file mode 100644
index 657835c..c1a34fb
*** a/doc/src/sgml/func.sgml
--- b/doc/src/sgml/func.sgml
***************
*** 82,89 ****
       <member><literal>NOT</></member>
      </simplelist>

!     <acronym>SQL</acronym> uses a three-valued Boolean logic where the null value represents
!     <quote>unknown</quote>.  Observe the following truth tables:

      <informaltable>
       <tgroup cols="4">
--- 82,90 ----
       <member><literal>NOT</></member>
      </simplelist>

!     <acronym>SQL</acronym> uses a three-valued logic system with true,
!     false, and <literal>null</>, which represents <quote>unknown</quote>.
!     Observe the following truth tables:

      <informaltable>
       <tgroup cols="4">