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-rw-r--r--doc/src/sgml/xaggr.sgml12
1 files changed, 4 insertions, 8 deletions
diff --git a/doc/src/sgml/xaggr.sgml b/doc/src/sgml/xaggr.sgml
index 1175b3640d7..1c34957a166 100644
--- a/doc/src/sgml/xaggr.sgml
+++ b/doc/src/sgml/xaggr.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/xaggr.sgml,v 1.38 2009/06/20 18:45:28 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/xaggr.sgml,v 1.39 2010/02/08 20:39:51 tgl Exp $ -->
<sect1 id="xaggr">
<title>User-Defined Aggregates</title>
@@ -166,14 +166,10 @@ SELECT attrelid::regclass, array_accum(atttypid::regtype)
<para>
A function written in C can detect that it is being called as an
- aggregate transition or final function by seeing if it was passed
- an <structname>AggState</> or <structname>WindowAggState</> node
- as the function call <quote>context</>,
- for example by:
+ aggregate transition or final function by calling
+ <function>AggCheckCallContext</>, for example:
<programlisting>
- if (fcinfo-&gt;context &amp;&amp;
- (IsA(fcinfo-&gt;context, AggState) ||
- IsA(fcinfo-&gt;context, WindowAggState)))
+ if (AggCheckCallContext(fcinfo, NULL))
</programlisting>
One reason for checking this is that when it is true for a transition
function, the first input