Commit f72aad56 authored by Tom Lane's avatar Tom Lane

Update discussion of aggregate syntax to mention ALL.

parent a7f85783
...@@ -711,6 +711,7 @@ sqrt(emp.salary) ...@@ -711,6 +711,7 @@ sqrt(emp.salary)
<simplelist> <simplelist>
<member><replaceable>aggregate_name</replaceable> (<replaceable>expression</replaceable>)</member> <member><replaceable>aggregate_name</replaceable> (<replaceable>expression</replaceable>)</member>
<member><replaceable>aggregate_name</replaceable> (ALL <replaceable>expression</replaceable>)</member>
<member><replaceable>aggregate_name</replaceable> (DISTINCT <replaceable>expression</replaceable>)</member> <member><replaceable>aggregate_name</replaceable> (DISTINCT <replaceable>expression</replaceable>)</member>
<member><replaceable>aggregate_name</replaceable> ( * )</member> <member><replaceable>aggregate_name</replaceable> ( * )</member>
</simplelist> </simplelist>
...@@ -723,7 +724,8 @@ sqrt(emp.salary) ...@@ -723,7 +724,8 @@ sqrt(emp.salary)
<para> <para>
The first form of aggregate expression invokes the aggregate across all The first form of aggregate expression invokes the aggregate across all
input rows for which the given expression yields a non-null value. input rows for which the given expression yields a non-null value.
The second form invokes the aggregate for all distinct non-null values The second form is the same as the first, since ALL is the default.
The third form invokes the aggregate for all distinct non-null values
of the expression found in the input rows. The last form invokes the of the expression found in the input rows. The last form invokes the
aggregate once for each input row regardless of null or non-null values; aggregate once for each input row regardless of null or non-null values;
since no particular input value is specified, it is generally only useful since no particular input value is specified, it is generally only useful
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