From e1089e34eb7625332a4e594cc50186a5233dc2b3 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Wed, 15 Sep 2010 17:45:57 +0000
Subject: [PATCH] Add a compatibility note about plpgsql's treatment of SELECT
INTO rec.fld when fld is of composite type. Per discussion of bug #5644 from
Valentine Gogichashvili.
---
doc/src/sgml/release-9.0.sgml | 27 ++++++++++++++++++++++++++-
1 file changed, 26 insertions(+), 1 deletion(-)
diff --git a/doc/src/sgml/release-9.0.sgml b/doc/src/sgml/release-9.0.sgml
index 7bfdf1419b0..6d29ddd1e93 100644
--- a/doc/src/sgml/release-9.0.sgml
+++ b/doc/src/sgml/release-9.0.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/release-9.0.sgml,v 2.55 2010/09/01 15:14:42 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/release-9.0.sgml,v 2.56 2010/09/15 17:45:57 tgl Exp $ -->
<sect1 id="release-9-0">
<title>Release 9.0</title>
@@ -434,6 +434,31 @@
</para>
</listitem>
+ <listitem>
+ <para>
+ PL/pgSQL now treats selection into composite fields more consistently
+ (Tom Lane)
+ </para>
+
+ <para>
+ Formerly, a statement like
+ <literal>SELECT ... INTO <replaceable>rec</>.<replaceable>fld</> FROM ...</literal>
+ was treated as a scalar assignment even if the record field
+ <replaceable>fld</> was of composite type. Now it is treated as a
+ record assignment, the same as when the <literal>INTO</> target is a
+ regular variable of composite type. So the values to be assigned to the
+ field's subfields should be written as separate columns of the
+ <command>SELECT</> list, not as a <literal>ROW(...)</> construct as in
+ previous versions.
+ </para>
+
+ <para>
+ If you need to do this in a way that will work in both 9.0 and previous
+ releases, you can write something like
+ <literal><replaceable>rec</>.<replaceable>fld</> := ROW(...) FROM ...</literal>.
+ </para>
+ </listitem>
+
<listitem>
<para>
Remove PL/pgSQL's <literal>RENAME</> declaration (Tom Lane)
--
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