diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/func.sgml | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index b3fe74fe502..978309d59ea 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.340 2006/09/22 16:20:00 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.341 2006/09/28 20:51:41 tgl Exp $ --> <chapter id="functions"> <title>Functions and Operators</title> @@ -338,6 +338,19 @@ </para> </tip> + <note> + <para> + If the <replaceable>expression</replaceable> is row-valued, then + <literal>IS NULL</> is true when the row expression itself is null + or when all the row's fields are null, while + <literal>IS NOT NULL</> is true when the row expression itself is non-null + and all the row's fields are non-null. + This definition conforms to the SQL standard, and is a change from the + inconsistent behavior exhibited by <productname>PostgreSQL</productname> + versions prior to 8.2. + </para> + </note> + <para> <indexterm> <primary>IS DISTINCT FROM</primary> |