diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7e1b488bae7..fb55b1bff72 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1,5 +1,5 @@
@@ -283,6 +283,18 @@ PostgreSQL documentation
+
+ IS NULL
+
+
+ IS NOT NULL
+
+
+ ISNULL
+
+
+ NOTNULL
+
To check whether a value is or is not null, use the constructs
expression IS NULL
@@ -305,6 +317,7 @@ PostgreSQL documentation
behavior conforms to the SQL standard.
+
Some applications may expect that
expression = NULL
@@ -318,8 +331,43 @@ PostgreSQL documentation
the default behavior in PostgreSQL
releases 6.5 through 7.1.
+
+
+ IS DISTINCT FROM
+
+ The ordinary comparison operators yield null (signifying unknown)
+ when either input is null. Another way to do comparisons is with the
+ IS DISTINCT FROM construct:
+
+expression IS DISTINCT FROM expression
+
+ For non-null inputs this is the same as the <> operator.
+ However, when both inputs are null it will return false, and when just
+ one input is null it will return true. Thus it effectively acts as though
+ null were a normal data value, rather than unknown.
+
+
+
+
+ IS TRUE
+
+
+ IS NOT TRUE
+
+
+ IS FALSE
+
+
+ IS NOT FALSE
+
+
+ IS UNKNOWN
+
+
+ IS NOT UNKNOWN
+
Boolean values can also be tested using the constructs
expression IS TRUE
@@ -329,9 +377,13 @@ PostgreSQL documentation
expression IS UNKNOWN
expression IS NOT UNKNOWN
- These are similar to IS NULL in that they will
- always return true or false, never a null value, even when the operand is null.
+ These will always return true or false, never a null value, even when the
+ operand is null.
A null input is treated as the logical value unknown.
+ Notice that IS UNKNOWN and IS NOT UNKNOWN are
+ effectively the same as IS NULL and
+ IS NOT NULL, respectively, except that the input
+ expression must be of Boolean type.
@@ -7344,7 +7396,7 @@ SELECT col1 FROM tab1
- <literal>NOT IN </literal>
+ <literal>NOT IN</literal>
expression NOT IN (subquery)
@@ -7538,9 +7590,9 @@ SELECT col1 FROM tab1
Row-wise Comparison
-
+
comparison
- of rows
+ subquery result row
@@ -7594,6 +7646,23 @@ SELECT col1 FROM tab1
SOME
+
+ comparison
+ row-wise
+
+
+
+ IS DISTINCT FROM
+
+
+
+ IS NULL
+
+
+
+ IS NOT NULL
+
+
This section describes several specialized constructs for making
multiple comparisons between groups of values. These forms are
diff --git a/doc/src/sgml/syntax.sgml b/doc/src/sgml/syntax.sgml
index 98deceb8957..99038b42692 100644
--- a/doc/src/sgml/syntax.sgml
+++ b/doc/src/sgml/syntax.sgml
@@ -1,5 +1,5 @@
@@ -1421,6 +1421,10 @@ SELECT name, (SELECT max(pop) FROM cities WHERE cities.state = states.name)
constructor
+
+ ARRAY
+
+
An array constructor is an expression that builds an
array value from values for its member elements. A simple array
@@ -1521,13 +1525,17 @@ SELECT ARRAY(SELECT oid FROM pg_proc WHERE proname LIKE 'bytea%');
constructor
+
+ ROW
+
+
A row constructor is an expression that builds a row value (also
called a composite value) from values
for its member fields. A row constructor consists of the key word
- ROW, a left parenthesis (, zero or more
+ ROW, a left parenthesis, zero or more
expressions (separated by commas) for the row field values, and finally
- a right parenthesis ). For example,
+ a right parenthesis. For example,
SELECT ROW(1,2.5,'this is a test');