Thread: BUG #6016: Documentation makes inappropriate reference to boolean logic
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
From
Bruce Momjian
Date:
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">