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-rw-r--r--doc/src/sgml/plpgsql.sgml4
-rw-r--r--doc/src/sgml/xfunc.sgml23
2 files changed, 23 insertions, 4 deletions
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index 4da3f3c0405..998ed72089e 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -1,5 +1,5 @@
<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/plpgsql.sgml,v 1.5 2002/08/30 00:28:40 tgl Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/plpgsql.sgml,v 1.6 2002/09/01 16:28:05 tgl Exp $
-->
<chapter id="plpgsql">
@@ -538,8 +538,6 @@ END;
<para>
Note that <literal>RECORD</> is not a true data type, only a placeholder.
- Thus, for example, one cannot declare a function returning
- <literal>RECORD</>.
</para>
</sect2>
diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml
index 9a7b79f0ddd..3999bf81769 100644
--- a/doc/src/sgml/xfunc.sgml
+++ b/doc/src/sgml/xfunc.sgml
@@ -1,5 +1,5 @@
<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/xfunc.sgml,v 1.59 2002/08/30 00:28:40 tgl Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/xfunc.sgml,v 1.60 2002/09/01 16:28:05 tgl Exp $
-->
<chapter id="xfunc">
@@ -2119,6 +2119,27 @@ SELECT * FROM vw_getfoo;
</programlisting>
are all valid statements.
</para>
+
+ <para>
+ In some cases it is useful to define table functions that can return
+ different column sets depending on how they are invoked. To support this,
+ the table function can be declared as returning the pseudo-type
+ <type>record</>. When such a function is used in a query, the expected
+ row structure must be specified in the query itself, so that the system
+ can know how to parse and plan the query. Consider this example:
+<programlisting>
+SELECT *
+FROM dblink('dbname=template1', 'select proname, prosrc from pg_proc')
+ AS t1(proname name, prosrc text)
+WHERE proname LIKE 'bytea%';
+</programlisting>
+ The <literal>dblink</> function executes a remote query (see
+ <literal>contrib/dblink</>). It is declared to return <type>record</>
+ since it might be used for any kind of query. The actual column set
+ must be specified in the calling query so that the parser knows, for
+ example, what <literal>*</> should expand to.
+ </para>
+
</sect1>
<sect1 id="xfunc-plhandler">