Initial SQL/XML support: xml data type and initial set of functions.

configure

@@ -894,6 +894,7 @@ Optional Packages:
   --with-openssl          build with OpenSSL support
   --without-readline      do not use GNU Readline nor BSD Libedit for editing
   --with-libedit-preferred  prefer BSD Libedit over GNU Readline
+  --with-libxml           build with XML support
   --without-zlib          do not use Zlib
   --with-gnu-ld           assume the C compiler uses GNU ld [default=no]
 
@@ -4160,6 +4161,42 @@ fi;
 
 
 
+#
+# XML
+#
+
+pgac_args="$pgac_args with_libxml"
+
+
+# Check whether --with-libxml or --without-libxml was given.
+if test "${with_libxml+set}" = set; then
+  withval="$with_libxml"
+
+  case $withval in
+    yes)
+
+cat >>confdefs.h <<\_ACEOF
+#define USE_LIBXML 1
+_ACEOF
+
+      ;;
+    no)
+      :
+      ;;
+    *)
+      { { echo "$as_me:$LINENO: error: no argument expected for --with-libxml option" >&5
+echo "$as_me: error: no argument expected for --with-libxml option" >&2;}
+   { (exit 1); exit 1; }; }
+      ;;
+  esac
+
+else
+  with_libxml=no
+
+fi;
+
+
+
 #
 # Zlib
 #
@@ -7268,6 +7305,87 @@ fi
 
 fi
 
+if test "$with_libxml" = yes ; then
+
+echo "$as_me:$LINENO: checking for xmlInitParser in -lxml2" >&5
+echo $ECHO_N "checking for xmlInitParser in -lxml2... $ECHO_C" >&6
+if test "${ac_cv_lib_xml2_xmlInitParser+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lxml2  $LIBS"
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+/* Override any gcc2 internal prototype to avoid an error.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+/* We use char because int might match the return type of a gcc2
+   builtin and then its argument prototype would still apply.  */
+char xmlInitParser ();
+int
+main ()
+{
+xmlInitParser ();
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_cv_lib_xml2_xmlInitParser=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_cv_lib_xml2_xmlInitParser=no
+fi
+rm -f conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+echo "$as_me:$LINENO: result: $ac_cv_lib_xml2_xmlInitParser" >&5
+echo "${ECHO_T}$ac_cv_lib_xml2_xmlInitParser" >&6
+if test $ac_cv_lib_xml2_xmlInitParser = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBXML2 1
+_ACEOF
+
+  LIBS="-lxml2 $LIBS"
+
+else
+  { { echo "$as_me:$LINENO: error: library 'xml2' is required for XML support" >&5
+echo "$as_me: error: library 'xml2' is required for XML support" >&2;}
+   { (exit 1); exit 1; }; }
+fi
+
+fi
+
 
 ##
 ## Header files
@@ -10359,6 +10477,155 @@ fi
 
 done
 
+fi
+
+if test "$with_libxml" = yes ; then
+  if test "${ac_cv_header_libxml_parser_h+set}" = set; then
+  echo "$as_me:$LINENO: checking for libxml/parser.h" >&5
+echo $ECHO_N "checking for libxml/parser.h... $ECHO_C" >&6
+if test "${ac_cv_header_libxml_parser_h+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+fi
+echo "$as_me:$LINENO: result: $ac_cv_header_libxml_parser_h" >&5
+echo "${ECHO_T}$ac_cv_header_libxml_parser_h" >&6
+else
+  # Is the header compilable?
+echo "$as_me:$LINENO: checking libxml/parser.h usability" >&5
+echo $ECHO_N "checking libxml/parser.h usability... $ECHO_C" >&6
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+$ac_includes_default
+#include <libxml/parser.h>
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_header_compiler=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_header_compiler=no
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+echo "$as_me:$LINENO: result: $ac_header_compiler" >&5
+echo "${ECHO_T}$ac_header_compiler" >&6
+
+# Is the header present?
+echo "$as_me:$LINENO: checking libxml/parser.h presence" >&5
+echo $ECHO_N "checking libxml/parser.h presence... $ECHO_C" >&6
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <libxml/parser.h>
+_ACEOF
+if { (eval echo "$as_me:$LINENO: \"$ac_cpp conftest.$ac_ext\"") >&5
+  (eval $ac_cpp conftest.$ac_ext) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } >/dev/null; then
+  if test -s conftest.err; then
+    ac_cpp_err=$ac_c_preproc_warn_flag
+    ac_cpp_err=$ac_cpp_err$ac_c_werror_flag
+  else
+    ac_cpp_err=
+  fi
+else
+  ac_cpp_err=yes
+fi
+if test -z "$ac_cpp_err"; then
+  ac_header_preproc=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+  ac_header_preproc=no
+fi
+rm -f conftest.err conftest.$ac_ext
+echo "$as_me:$LINENO: result: $ac_header_preproc" >&5
+echo "${ECHO_T}$ac_header_preproc" >&6
+
+# So?  What about this header?
+case $ac_header_compiler:$ac_header_preproc:$ac_c_preproc_warn_flag in
+  yes:no: )
+    { echo "$as_me:$LINENO: WARNING: libxml/parser.h: accepted by the compiler, rejected by the preprocessor!" >&5
+echo "$as_me: WARNING: libxml/parser.h: accepted by the compiler, rejected by the preprocessor!" >&2;}
+    { echo "$as_me:$LINENO: WARNING: libxml/parser.h: proceeding with the compiler's result" >&5
+echo "$as_me: WARNING: libxml/parser.h: proceeding with the compiler's result" >&2;}
+    ac_header_preproc=yes
+    ;;
+  no:yes:* )
+    { echo "$as_me:$LINENO: WARNING: libxml/parser.h: present but cannot be compiled" >&5
+echo "$as_me: WARNING: libxml/parser.h: present but cannot be compiled" >&2;}
+    { echo "$as_me:$LINENO: WARNING: libxml/parser.h:     check for missing prerequisite headers?" >&5
+echo "$as_me: WARNING: libxml/parser.h:     check for missing prerequisite headers?" >&2;}
+    { echo "$as_me:$LINENO: WARNING: libxml/parser.h: see the Autoconf documentation" >&5
+echo "$as_me: WARNING: libxml/parser.h: see the Autoconf documentation" >&2;}
+    { echo "$as_me:$LINENO: WARNING: libxml/parser.h:     section \"Present But Cannot Be Compiled\"" >&5
+echo "$as_me: WARNING: libxml/parser.h:     section \"Present But Cannot Be Compiled\"" >&2;}
+    { echo "$as_me:$LINENO: WARNING: libxml/parser.h: proceeding with the preprocessor's result" >&5
+echo "$as_me: WARNING: libxml/parser.h: proceeding with the preprocessor's result" >&2;}
+    { echo "$as_me:$LINENO: WARNING: libxml/parser.h: in the future, the compiler will take precedence" >&5
+echo "$as_me: WARNING: libxml/parser.h: in the future, the compiler will take precedence" >&2;}
+    (
+      cat <<\_ASBOX
+## ---------------------------------------- ##
+## Report this to pgsql-bugs@postgresql.org ##
+## ---------------------------------------- ##
+_ASBOX
+    ) |
+      sed "s/^/$as_me: WARNING:     /" >&2
+    ;;
+esac
+echo "$as_me:$LINENO: checking for libxml/parser.h" >&5
+echo $ECHO_N "checking for libxml/parser.h... $ECHO_C" >&6
+if test "${ac_cv_header_libxml_parser_h+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  ac_cv_header_libxml_parser_h=$ac_header_preproc
+fi
+echo "$as_me:$LINENO: result: $ac_cv_header_libxml_parser_h" >&5
+echo "${ECHO_T}$ac_cv_header_libxml_parser_h" >&6
+
+fi
+if test $ac_cv_header_libxml_parser_h = yes; then
+  :
+else
+  { { echo "$as_me:$LINENO: error: header file <libxml/parser.h> is required for XML support" >&5
+echo "$as_me: error: header file <libxml/parser.h> is required for XML support" >&2;}
+   { (exit 1); exit 1; }; }
+fi
+
+
 fi
 
 if test "$with_ldap" = yes ; then

configure.in

 dnl Process this file with autoconf to produce a configure script.
-dnl $PostgreSQL: pgsql/configure.in,v 1.492 2006/12/14 21:49:54 tgl Exp $
+dnl $PostgreSQL: pgsql/configure.in,v 1.493 2006/12/21 16:05:12 petere Exp $
 dnl
 dnl Developers, please strive to achieve this order:
 dnl
@@ -531,6 +531,13 @@ PGAC_ARG_BOOL(with, libedit-preferred, no,
               [  --with-libedit-preferred  prefer BSD Libedit over GNU Readline])
 
 
+#
+# XML
+#
+PGAC_ARG_BOOL(with, libxml, no, [  --with-libxml           build with XML support],
+              [AC_DEFINE([USE_LIBXML], 1, [Define to 1 to build with XML support. (--with-libxml)])])
+
+
 #
 # Zlib
 #
@@ -716,6 +723,10 @@ if test "$with_pam" = yes ; then
   AC_CHECK_LIB(pam,    pam_start, [], [AC_MSG_ERROR([library 'pam' is required for PAM])])
 fi
 
+if test "$with_libxml" = yes ; then
+  AC_CHECK_LIB(xml2, xmlInitParser, [], [AC_MSG_ERROR([library 'xml2' is required for XML support])])
+fi
+
 
 ##
 ## Header files
@@ -791,6 +802,10 @@ if test "$with_pam" = yes ; then
                                      [AC_MSG_ERROR([header file <security/pam_appl.h> or <pam/pam_appl.h> is required for PAM.])])])
 fi
 
+if test "$with_libxml" = yes ; then
+  AC_CHECK_HEADER(libxml/parser.h, [], [AC_MSG_ERROR([header file <libxml/parser.h> is required for XML support])])
+fi
+
 if test "$with_ldap" = yes ; then
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_HEADERS(ldap.h, [],

doc/src/sgml/datatype.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.181 2006/11/23 04:27:33 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.182 2006/12/21 16:05:12 petere Exp $ -->
 
  <chapter id="datatype">
   <title id="datatype-title">Data Types</title>
@@ -233,6 +233,12 @@
        <entry><type>timestamptz</type></entry>
        <entry>date and time, including time zone</entry>
       </row>
+
+      <row>
+       <entry><type>xml</type></entry>
+       <entry></entry>
+       <entry>XML data</entry>
+      </row>
      </tbody>
     </tgroup>
    </table>
@@ -248,7 +254,8 @@
     precision</type>, <type>integer</type>, <type>interval</type>,
     <type>numeric</type>, <type>decimal</type>, <type>real</type>,
     <type>smallint</type>, <type>time</type> (with or without time zone),
-    <type>timestamp</type> (with or without time zone).
+    <type>timestamp</type> (with or without time zone),
+    <type>xml</type>.
    </para>
   </note>
 
@@ -3358,12 +3365,21 @@ SELECT * FROM pg_attribute
   </sect1>
 
   <sect1 id="datatype-xml">
-   <title><acronym>XML</> Document Support</title>
+   <title><acronym>XML</> Type</title>
 
-   <indexterm zone="datatype">
-    <primary>xml</primary>
+   <indexterm zone="datatype-xml">
+    <primary>XML</primary>
    </indexterm>
 
+   <para>
+    The data type <type>xml</type> can be used to store XML data.  Its
+    advantage over storing XML data in, say, a text field is that it
+    checks the input values for well-formedness, and there are support
+    functions to perform type-safe operations on it; see <xref
+    linkend="functions-xml">.  Currently, there is no support for
+    validation against a specific <acronym>XML</> schema.
+   </para>
+
    <para>
     <acronym>XML</> (Extensible Markup Language) support is not one
     capability, but a variety of features supported by a database
@@ -3378,22 +3394,6 @@ SELECT * FROM pg_attribute
    </para>
 
    <variablelist>
-
-   <varlistentry>
-    <term>Storage</term>
-    <listitem>
-
-     <para>
-      PostgreSQL does not have a specialized <acronym>XML</> data type.
-      Users should store <acronym>XML</> documents in ordinary
-      <type>TEXT</> fields. If you need the document split apart into
-      its component parts so each element is stored separately, you must
-      use a middle-ware solution to do that, but once done, the data
-      becomes relational and has to be processed accordingly.
-     </para>
-    </listitem>
-   </varlistentry>
-
    <varlistentry>
     <term>Import/Export</term>
     <listitem>
@@ -3408,21 +3408,6 @@ SELECT * FROM pg_attribute
     </listitem>
    </varlistentry>
 
-   <varlistentry>
-    <term>Validation</term>
-    <listitem>
-
-     <para>
-      <filename>/contrib/xml2</> has a function called
-      <function>xml_is_well_formed()</> that can be used in a <literal>CHECK</>
-      constraint to enforce that a field contains well-formed <acronym>XML</>.
-      It does not support validation against a specific <acronym>XML</>
-      schema. A server-side language with <acronym>XML</> capabilities
-      could be used to do schema-specific <acronym>XML</> checks.
-     </para>
-    </listitem>
-   </varlistentry>
-
    <varlistentry>
     <term>Indexing</term>
     <listitem>
@@ -3438,20 +3423,6 @@ SELECT * FROM pg_attribute
     </listitem>
    </varlistentry>
 
-   <varlistentry>
-    <term>Modification</term>
-    <listitem>
-
-     <para>
-      If an <command>UPDATE</> does not modify an <acronym>XML</> field,
-      the <acronym>XML</> data is shared between the old and new rows.
-      However, if the <command>UPDATE</> modifies an <acronym>XML</>
-      field, a full modified copy of the <acronym>XML</> field must be
-      created internally.
-     </para>
-    </listitem>
-   </varlistentry>
-
    <varlistentry>
     <term>Searching</term>
     <listitem>
@@ -3487,19 +3458,6 @@ SELECT * FROM pg_attribute
      </para>
     </listitem>
    </varlistentry>
-
-   <varlistentry>
-    <term>Missing Features</term>
-    <listitem>
-
-     <para>
-      Missing features include XQuery, SQL/XML syntax (ISO/IEC
-      9075-14), and an <acronym>XML</> data type optimized for
-      <acronym>XML</> storage.
-     </para>
-    </listitem>
-   </varlistentry>
-
    </variablelist>
 
   </sect1>

doc/src/sgml/func.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.347 2006/11/25 00:38:53 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.348 2006/12/21 16:05:12 petere Exp $ -->
 
  <chapter id="functions">
   <title>Functions and Operators</title>
@@ -10741,4 +10741,113 @@ SELECT (pg_stat_file('filename')).modification;
    </para>
 
   </sect1>
+
+  <sect1 id="functions-xml">
+   <title>XML Functions</title>
+
+   <para>
+    The functions and function-like expressions described in this
+    section operate on values of type <type>xml</type>.
+   </para>
+
+   <sect2>
+    <title><literal>xmlcomment</literal></title>
+ 
+   <indexterm>
+    <primary>xmlcomment</primary>
+   </indexterm>
+ 
+ <synopsis>
+ <function>xmlcomment</function>(<replaceable>text</replaceable>)
+ </synopsis>
+ 
+    <para>
+     Creates an XML comment.
+    </para>
+    </sect2>
+ 
+   <sect2>
+    <title><literal>xmlconcat</literal></title>
+ 
+   <indexterm>
+    <primary>xmlconcat</primary>
+   </indexterm>
+ 
+ <synopsis>
+ <function>xmlconcat</function>(<replaceable>xml</replaceable><optional>, xml, ...</optional>)
+ </synopsis>
+ 
+    <para>
+     Combines a list of individual XML values to create a
+     single value containing an XML forest.
+    </para>
+    </sect2>
+ 
+   <sect2>
+    <title><literal>xmlelement</literal></title>
+ 
+   <indexterm>
+    <primary>xmlelement</primary>
+   </indexterm>
+ 
+ <synopsis>
+ <function>xmlelement</function>(name <replaceable>name</replaceable><optional>, xmlattribytes(<replaceable>value</replaceable> <optional>AS <replaceable>label</replaceable></optional><optional>, ... </optional>)</optional>
+ <optional><replaceable>, content, ...</replaceable></optional>)
+ </synopsis>
+ 
+    <para>
+     Creates an XML element, allowing the name to be specified.
+    </para>
+    </sect2>
+ 
+   <sect2>
+    <title><literal>xmlforest</literal></title>
+ 
+   <indexterm>
+    <primary>xmlforest</primary>
+   </indexterm>
+ 
+ <synopsis>
+ <function>xmlforest</function>(<replaceable>value</replaceable> <optional>AS <replaceable>label</replaceable></optional><optional>, ...</optional>)
+ </synopsis>
+ 
+    <para>
+     Creates XML elements from columns, using the name of each
+     column as the name of the corresponding element.
+    </para>
+    </sect2>
+ 
+   <sect2>
+    <title><literal>xmlpi</literal></title>
+ 
+   <indexterm>
+    <primary>xmlpi</primary>
+   </indexterm>
+ 
+ <synopsis>
+ <function>xmlpi</function>(name <replaceable>target</replaceable> <optional>, <replaceable>content</replaceable></optional>)
+ </synopsis>
+ 
+    <para>
+     Creates an XML processing instruction.
+    </para>
+    </sect2>
+ 
+   <sect2>
+    <title><literal>xmlroot</literal></title>
+ 
+   <indexterm>
+    <primary>xmlroot</primary>
+   </indexterm>
+ 
+ <synopsis>
+ <function>xmlroot</function>(<replaceable>xml</replaceable>, version <replaceable>text</replaceable> <optional>, standalone yes|no|no value</optional>)
+ </synopsis>
+ 
+    <para>
+     Creates the root node of an XML document.
+    </para>
+  </sect2>
+ 
+ </sect1>
 </chapter>

doc/src/sgml/installation.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/installation.sgml,v 1.268 2006/12/02 09:29:51 petere Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/installation.sgml,v 1.269 2006/12/21 16:05:13 petere Exp $ -->
 
 <chapter id="installation">
  <title><![%standalone-include[<productname>PostgreSQL</>]]>
@@ -905,6 +905,15 @@ su - postgres
        </listitem>
       </varlistentry>
 
+      <varlistentry>
+       <term><option>--with-libxml</option></term>
+       <listitem>
+        <para>
+         Build with libxml, required for SQL/XML support.
+        </para>
+       </listitem>
+      </varlistentry>
+
       <varlistentry>
        <term><option>--enable-integer-datetimes</option></term>
        <listitem>

src/backend/executor/execQual.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.199 2006/11/17 16:46:27 petere Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.200 2006/12/21 16:05:13 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -52,6 +52,7 @@
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
 #include "utils/typcache.h"
+#include "utils/xml.h"
 
 
 /* static function decls */
@@ -119,6 +120,8 @@ static Datum ExecEvalMinMax(MinMaxExprState *minmaxExpr,
 static Datum ExecEvalNullIf(FuncExprState *nullIfExpr,
 			   ExprContext *econtext,
 			   bool *isNull, ExprDoneCond *isDone);
+static Datum ExecEvalXml(XmlExprState *xmlExpr, ExprContext *econtext,
+						 bool *isNull, ExprDoneCond *isDone);
 static Datum ExecEvalNullTest(NullTestState *nstate,
 				 ExprContext *econtext,
 				 bool *isNull, ExprDoneCond *isDone);
@@ -2878,6 +2881,120 @@ ExecEvalBooleanTest(GenericExprState *bstate,
 	}
 }
 
+/* ----------------------------------------------------------------
+ *		ExecEvalXml
+ * ----------------------------------------------------------------
+ */
+ 
+static Datum
+ExecEvalXml(XmlExprState *xmlExpr, ExprContext *econtext,
+			bool *isNull, ExprDoneCond *isDone)
+{
+	StringInfoData 	buf;
+	bool 			isnull;
+	ListCell 	   *arg;
+	text 		   *result = NULL;
+	int 			len;
+
+	initStringInfo(&buf);
+
+	*isNull = false;
+
+	if (isDone)
+		*isDone = ExprSingleResult;
+
+	switch (xmlExpr->op)
+	{
+		case IS_XMLCONCAT:
+			*isNull = true;
+
+			foreach(arg, xmlExpr->args)
+			{
+				ExprState 	*e = (ExprState *) lfirst(arg);
+				Datum 		value = ExecEvalExpr(e, econtext, &isnull, NULL);
+
+				if (!isnull)
+				{
+					appendStringInfoString(&buf, DatumGetCString(OidFunctionCall1(xmlExpr->arg_typeout, value)));
+					*isNull = false;
+				}
+			}
+			break;
+
+		case IS_XMLELEMENT:
+			{
+				int state = 0, i = 0;
+				appendStringInfo(&buf, "<%s", xmlExpr->name);
+				foreach(arg, xmlExpr->named_args)
+				{
+					GenericExprState *gstate = (GenericExprState *) lfirst(arg);
+					Datum value = ExecEvalExpr(gstate->arg, econtext, &isnull, NULL);
+					if (!isnull)
+					{
+						char *outstr = DatumGetCString(OidFunctionCall1(xmlExpr->named_args_tcache[i], value));
+						appendStringInfo(&buf, " %s=\"%s\"", xmlExpr->named_args_ncache[i], outstr);
+						pfree(outstr);
+					}
+					i++;
+				}
+				if (xmlExpr->args)
+				{
+					ExprState 	*expr = linitial(xmlExpr->args);
+					Datum 		value = ExecEvalExpr(expr, econtext, &isnull, NULL);
+
+					if (!isnull)
+					{
+						char *outstr = DatumGetCString(OidFunctionCall1(xmlExpr->arg_typeout, value));
+						if (state == 0)
+						{
+							appendStringInfoChar(&buf, '>');
+							state = 1;
+						}
+						appendStringInfo(&buf, "%s", outstr);
+						pfree(outstr);
+					}
+			 	}
+
+				if (state == 0)
+					appendStringInfo(&buf, "/>");
+			 	else if (state == 1)
+					appendStringInfo(&buf, "</%s>", xmlExpr->name);		
+
+			}
+			break;
+
+		case IS_XMLFOREST:
+			{
+				/* only if all argumets are null returns null */
+				int i = 0; 
+				*isNull = true;
+				foreach(arg, xmlExpr->named_args)
+			 	{
+					GenericExprState *gstate = (GenericExprState *) lfirst(arg);
+					Datum value = ExecEvalExpr(gstate->arg, econtext, &isnull, NULL);
+					if (!isnull)
+					{
+						char *outstr = DatumGetCString(OidFunctionCall1(xmlExpr->named_args_tcache[i], value));
+						appendStringInfo(&buf, "<%s>%s</%s>", xmlExpr->named_args_ncache[i], outstr, xmlExpr->named_args_ncache[i]);
+						pfree(outstr);
+						*isNull = false;
+					}
+					i += 1;
+				}		
+			}
+			break;
+		default:
+			break;
+	}
+
+	len = buf.len + VARHDRSZ;
+	result = palloc(len);
+	VARATT_SIZEP(result) = len;
+	memcpy(VARDATA(result), buf.data, buf.len);
+	pfree(buf.data);
+	PG_RETURN_TEXT_P(result);
+}
+
 /*
  * ExecEvalCoerceToDomain
  *
@@ -3668,6 +3785,64 @@ ExecInitExpr(Expr *node, PlanState *parent)
 				state = (ExprState *) mstate;
 			}
 			break;
+		case T_XmlExpr:
+			{
+				List			*outlist; 
+				ListCell		*arg;
+				XmlExpr			*xexpr = (XmlExpr *) node;
+				XmlExprState	*xstate = makeNode(XmlExprState);
+				int				i = 0; 
+				Oid				typeout;
+		
+				xstate->name = xexpr->name;
+								
+				xstate->xprstate.evalfunc = (ExprStateEvalFunc) ExecEvalXml;
+				xstate->op = xexpr->op;
+				
+				outlist = NIL;
+				if (xexpr->named_args)
+				{
+					xstate->named_args_tcache = (Oid *) palloc(list_length(xexpr->named_args) * sizeof(int));
+					xstate->named_args_ncache = (char **) palloc(list_length(xexpr->named_args) * sizeof(char *));
+					
+					i = 0;
+					foreach(arg, xexpr->named_args)
+					{
+						bool		tpisvarlena;
+						Expr		*e = (Expr *) lfirst(arg);
+						ExprState	*estate = ExecInitExpr(e, parent);
+						TargetEntry	*tle;
+						outlist = lappend(outlist, estate);					
+						tle = (TargetEntry *) ((GenericExprState *) estate)->xprstate.expr;
+						getTypeOutputInfo(exprType((Node *)tle->expr), &typeout, &tpisvarlena);
+						xstate->named_args_ncache[i] = tle->resname;
+						xstate->named_args_tcache[i] = typeout;
+						i++;
+					}	
+				}
+				else
+				{
+					xstate->named_args_tcache = NULL;
+					xstate->named_args_ncache = NULL;
+				}
+				xstate->named_args = outlist;
+
+				outlist = NIL;				
+				foreach(arg, xexpr->args)
+				{
+					bool 		tpisvarlena;
+					ExprState 	*estate;
+					Expr 		*e = (Expr *) lfirst(arg);
+					getTypeOutputInfo(exprType((Node *)e), &typeout, &tpisvarlena);
+					estate = ExecInitExpr(e, parent);
+					outlist = lappend(outlist, estate);
+				}
+				xstate->arg_typeout = typeout;
+				xstate->args = outlist;
+				
+				state = (ExprState *) xstate;
+			}
+			break;
 		case T_NullIfExpr:
 			{
 				NullIfExpr *nullifexpr = (NullIfExpr *) node;

src/backend/nodes/copyfuncs.c

@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.354 2006/12/10 22:13:26 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.355 2006/12/21 16:05:13 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1136,6 +1136,22 @@ _copyBooleanTest(BooleanTest *from)
 	return newnode;
 }
 
+/*
+ * _copyXmlExpr
+ */
+static XmlExpr *
+_copyXmlExpr(XmlExpr *from)
+{
+	XmlExpr *newnode = makeNode(XmlExpr);
+
+	COPY_SCALAR_FIELD(op);
+	COPY_STRING_FIELD(name);
+	COPY_NODE_FIELD(named_args);
+	COPY_NODE_FIELD(args);
+
+	return newnode;
+}
+
 /*
  * _copyCoerceToDomain
  */
@@ -2966,6 +2982,9 @@ copyObject(void *from)
 		case T_BooleanTest:
 			retval = _copyBooleanTest(from);
 			break;
+		case T_XmlExpr:
+			retval = _copyXmlExpr(from);
+			break;
 		case T_CoerceToDomain:
 			retval = _copyCoerceToDomain(from);
 			break;

src/backend/nodes/equalfuncs.c

@@ -18,7 +18,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.288 2006/12/10 22:13:26 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.289 2006/12/21 16:05:13 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -495,6 +495,17 @@ _equalBooleanTest(BooleanTest *a, BooleanTest *b)
 	return true;
 }
 
+static bool
+_equalXmlExpr(XmlExpr *a, XmlExpr *b)
+{
+	COMPARE_SCALAR_FIELD(op);
+	COMPARE_STRING_FIELD(name);
+	COMPARE_NODE_FIELD(named_args);
+	COMPARE_NODE_FIELD(args);
+
+	return true;
+}
+
 static bool
 _equalCoerceToDomain(CoerceToDomain *a, CoerceToDomain *b)
 {
@@ -1968,6 +1979,9 @@ equal(void *a, void *b)
 		case T_BooleanTest:
 			retval = _equalBooleanTest(a, b);
 			break;
+		case T_XmlExpr:
+			retval = _equalXmlExpr(a, b);
+			break;
 		case T_CoerceToDomain:
 			retval = _equalCoerceToDomain(a, b);
 			break;

src/backend/nodes/outfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.286 2006/12/10 22:13:26 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.287 2006/12/21 16:05:13 petere Exp $
  *
  * NOTES
  *	  Every node type that can appear in stored rules' parsetrees *must*
@@ -920,6 +920,17 @@ _outBooleanTest(StringInfo str, BooleanTest *node)
 	WRITE_ENUM_FIELD(booltesttype, BoolTestType);
 }
 
+static void
+_outXmlExpr(StringInfo str, XmlExpr *node)
+{
+	WRITE_NODE_TYPE("XMLEXPR");
+	
+	WRITE_ENUM_FIELD(op, XmlExprOp);
+	WRITE_STRING_FIELD(name);
+	WRITE_NODE_FIELD(named_args);
+	WRITE_NODE_FIELD(args);
+}
+
 static void
 _outCoerceToDomain(StringInfo str, CoerceToDomain *node)
 {
@@ -2019,6 +2030,9 @@ _outNode(StringInfo str, void *obj)
 			case T_BooleanTest:
 				_outBooleanTest(str, obj);
 				break;
+			case T_XmlExpr:
+				_outXmlExpr(str, obj);
+				break;
 			case T_CoerceToDomain:
 				_outCoerceToDomain(str, obj);
 				break;

src/backend/nodes/readfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/readfuncs.c,v 1.196 2006/12/10 22:13:26 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/readfuncs.c,v 1.197 2006/12/21 16:05:13 petere Exp $
  *
  * NOTES
  *	  Path and Plan nodes do not have any readfuncs support, because we
@@ -764,6 +764,22 @@ _readBooleanTest(void)
 	READ_DONE();
 }
 
+/*
+ * _readXmlExpr
+ */
+static XmlExpr *
+_readXmlExpr(void)
+{
+	READ_LOCALS(XmlExpr);
+
+	READ_ENUM_FIELD(op, XmlExprOp);
+	READ_STRING_FIELD(name);
+	READ_NODE_FIELD(named_args);
+	READ_NODE_FIELD(args);
+
+	READ_DONE();
+}
+
 /*
  * _readCoerceToDomain
  */
@@ -1014,6 +1030,8 @@ parseNodeString(void)
 		return_value = _readNullTest();
 	else if (MATCH("BOOLEANTEST", 11))
 		return_value = _readBooleanTest();
+	else if (MATCH("XMLEXPR", 7))
+		return_value = _readXmlExpr();
 	else if (MATCH("COERCETODOMAIN", 14))
 		return_value = _readCoerceToDomain();
 	else if (MATCH("COERCETODOMAINVALUE", 19))

src/backend/optimizer/util/clauses.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.223 2006/10/25 22:11:32 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.224 2006/12/21 16:05:13 petere Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -559,6 +559,8 @@ expression_returns_set_walker(Node *node, void *context)
 		return false;
 	if (IsA(node, NullIfExpr))
 		return false;
+	if (IsA(node, XmlExpr))
+		return false;
 
 	return expression_tree_walker(node, expression_returns_set_walker,
 								  context);
@@ -876,6 +878,8 @@ contain_nonstrict_functions_walker(Node *node, void *context)
 		return true;
 	if (IsA(node, BooleanTest))
 		return true;
+	if (IsA(node, XmlExpr))
+		return true;
 	return expression_tree_walker(node, contain_nonstrict_functions_walker,
 								  context);
 }
@@ -3334,6 +3338,16 @@ expression_tree_walker(Node *node,
 			return walker(((NullTest *) node)->arg, context);
 		case T_BooleanTest:
 			return walker(((BooleanTest *) node)->arg, context);
+		case T_XmlExpr:
+			{
+				XmlExpr *xexpr = (XmlExpr *) node;
+				
+				if (walker(xexpr->named_args, context))
+					return true;
+				if (walker(xexpr->args, context))
+					return true;
+			}
+			break;
 		case T_CoerceToDomain:
 			return walker(((CoerceToDomain *) node)->arg, context);
 		case T_TargetEntry:
@@ -3857,6 +3871,17 @@ expression_tree_mutator(Node *node,
 				return (Node *) newnode;
 			}
 			break;
+		case T_XmlExpr:
+			{
+				XmlExpr *xexpr = (XmlExpr *) node;
+				XmlExpr *newnode;
+
+				FLATCOPY(newnode, xexpr, XmlExpr);
+				MUTATE(newnode->named_args, xexpr->named_args, List *);
+				MUTATE(newnode->args, xexpr->args, List *);
+				return (Node *) newnode;
+			}
+			break;
 		case T_NullIfExpr:
 			{
 				NullIfExpr *expr = (NullIfExpr *) node;

src/backend/parser/gram.y

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.568 2006/11/05 22:42:09 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.569 2006/12/21 16:05:14 petere Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -106,6 +106,7 @@ static void insertSelectOptions(SelectStmt *stmt,
 static Node *makeSetOp(SetOperation op, bool all, Node *larg, Node *rarg);
 static Node *doNegate(Node *n, int location);
 static void doNegateFloat(Value *v);
+static Node *makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args);
 
 %}
 
@@ -345,6 +346,11 @@ static void doNegateFloat(Value *v);
 %type <str>		OptTableSpace OptConsTableSpace OptTableSpaceOwner
 %type <list>	opt_check_option
 
+%type <target>	xml_attribute_el
+%type <list>	xml_attribute_list xml_attributes
+%type <node>	xml_root_version
+%type <ival>	opt_xml_root_standalone document_or_content xml_whitespace_option
+
 
 /*
  * If you make any token changes, update the keyword table in
@@ -365,13 +371,13 @@ static void doNegateFloat(Value *v);
 	CHARACTER CHARACTERISTICS CHECK CHECKPOINT CLASS CLOSE
 	CLUSTER COALESCE COLLATE COLUMN COMMENT COMMIT
 	COMMITTED CONCURRENTLY CONNECTION CONSTRAINT CONSTRAINTS
-	CONVERSION_P CONVERT COPY CREATE CREATEDB
+	CONTENT CONVERSION_P CONVERT COPY CREATE CREATEDB
 	CREATEROLE CREATEUSER CROSS CSV CURRENT_DATE CURRENT_ROLE CURRENT_TIME
 	CURRENT_TIMESTAMP CURRENT_USER CURSOR CYCLE
 
 	DATABASE DAY_P DEALLOCATE DEC DECIMAL_P DECLARE DEFAULT DEFAULTS
 	DEFERRABLE DEFERRED DEFINER DELETE_P DELIMITER DELIMITERS
-	DESC DISABLE_P DISTINCT DO DOMAIN_P DOUBLE_P DROP
+	DESC DISABLE_P DISTINCT DO DOCUMENT DOMAIN_P DOUBLE_P DROP
 
 	EACH ELSE ENABLE_P ENCODING ENCRYPTED END_P ESCAPE EXCEPT EXCLUDING
 	EXCLUSIVE EXECUTE EXISTS EXPLAIN EXTERNAL EXTRACT
@@ -398,7 +404,7 @@ static void doNegateFloat(Value *v);
 
 	MATCH MAXVALUE MINUTE_P MINVALUE MODE MONTH_P MOVE
 
-	NAMES NATIONAL NATURAL NCHAR NEW NEXT NO NOCREATEDB
+	NAME NAMES NATIONAL NATURAL NCHAR NEW NEXT NO NOCREATEDB
 	NOCREATEROLE NOCREATEUSER NOINHERIT NOLOGIN_P NONE NOSUPERUSER
 	NOT NOTHING NOTIFY NOTNULL NOWAIT NULL_P NULLIF NUMERIC
 
@@ -417,8 +423,8 @@ static void doNegateFloat(Value *v);
 
 	SAVEPOINT SCHEMA SCROLL SECOND_P SECURITY SELECT SEQUENCE
 	SERIALIZABLE SESSION SESSION_USER SET SETOF SHARE
-	SHOW SIMILAR SIMPLE SMALLINT SOME STABLE START STATEMENT
-	STATISTICS STDIN STDOUT STORAGE STRICT_P SUBSTRING SUPERUSER_P SYMMETRIC
+	SHOW SIMILAR SIMPLE SMALLINT SOME STABLE STANDALONE START STATEMENT
+	STATISTICS STDIN STDOUT STORAGE STRICT_P STRIP SUBSTRING SUPERUSER_P SYMMETRIC
 	SYSID SYSTEM_P
 
 	TABLE TABLESPACE TEMP TEMPLATE TEMPORARY THEN TIME TIMESTAMP
@@ -428,12 +434,15 @@ static void doNegateFloat(Value *v);
 	UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN UNLISTEN UNTIL
 	UPDATE USER USING
 
-	VACUUM VALID VALIDATOR VALUES VARCHAR VARYING
-	VERBOSE VIEW VOLATILE
+	VACUUM VALID VALIDATOR VALUE VALUES VARCHAR VARYING
+	VERBOSE VERSION VIEW VOLATILE
+
+	WHEN WHERE WHITESPACE WITH WITHOUT WORK WRITE
 
-	WHEN WHERE WITH WITHOUT WORK WRITE
+	XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLFOREST XMLPARSE
+	XMLPI XMLROOT XMLSERIALIZE
 
-	YEAR_P
+	YEAR_P YES
 
 	ZONE
 
@@ -484,6 +493,7 @@ static void doNegateFloat(Value *v);
  * left-associativity among the JOIN rules themselves.
  */
 %left		JOIN CROSS LEFT FULL RIGHT INNER_P NATURAL
+%right		PRESERVE STRIP
 %%
 
 /*
@@ -7868,6 +7878,146 @@ func_expr:	func_name '(' ')'
 					v->op = IS_LEAST;
 					$$ = (Node *)v;
 				}
+			| XMLCONCAT '(' expr_list ')'
+				{		
+					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NULL, $3);
+				}
+			| XMLELEMENT '(' NAME ColLabel ')'
+				{
+					$$ = makeXmlExpr(IS_XMLELEMENT, $4, NULL, NULL);
+				}
+			| XMLELEMENT '(' NAME ColLabel ',' xml_attributes ')'
+				{
+					$$ = makeXmlExpr(IS_XMLELEMENT, $4, $6, NULL);
+				}
+			| XMLELEMENT '(' NAME ColLabel ',' expr_list ')'
+				{
+					$$ = makeXmlExpr(IS_XMLELEMENT, $4, NULL, $6);
+				}
+			| XMLELEMENT '(' NAME ColLabel ',' xml_attributes ',' expr_list ')'
+				{
+					$$ = makeXmlExpr(IS_XMLELEMENT, $4, $6, $8);
+				}
+			| XMLFOREST '(' xml_attribute_list ')'
+				{
+					$$ = makeXmlExpr(IS_XMLFOREST, NULL, $3, NULL);
+				}
+			| XMLPARSE '(' document_or_content a_expr xml_whitespace_option ')'
+				{
+					FuncCall *n = makeNode(FuncCall);
+					n->funcname = SystemFuncName("xmlparse");
+					n->args = list_make3(makeBoolAConst($3 == DOCUMENT), $4, makeBoolAConst($5 == PRESERVE));
+					n->agg_star = FALSE;
+					n->agg_distinct = FALSE;
+					n->location = @1;
+					$$ = (Node *)n;
+				}
+			| XMLPI '(' NAME ColLabel ')'
+				{
+					FuncCall *n = makeNode(FuncCall);
+					n->funcname = SystemFuncName("xmlpi");
+					n->args = list_make1(makeStringConst($4, NULL));
+					n->agg_star = FALSE;
+					n->agg_distinct = FALSE;
+					n->location = @1;
+					$$ = (Node *)n;
+				}
+			| XMLPI '(' NAME ColLabel ',' a_expr ')'
+				{
+					FuncCall *n = makeNode(FuncCall);
+					n->funcname = SystemFuncName("xmlpi");
+					n->args = list_make2(makeStringConst($4, NULL), $6);
+					n->agg_star = FALSE;
+					n->agg_distinct = FALSE;
+					n->location = @1;
+					$$ = (Node *)n;
+				}
+			| XMLROOT '(' a_expr ',' xml_root_version opt_xml_root_standalone ')'
+				{
+					FuncCall *n = makeNode(FuncCall);
+					Node *ver;
+					A_Const *sa;
+
+					if ($5)
+						ver = $5;
+					else
+					{
+						A_Const *val;
+
+						val = makeNode(A_Const);
+						val->val.type = T_Null;
+						ver = (Node *) val;
+					}
+
+					if ($6)
+						sa = makeBoolAConst($6 == 1);
+					else
+					{
+						sa = makeNode(A_Const);
+						sa->val.type = T_Null;
+					}
+
+					n->funcname = SystemFuncName("xmlroot");
+					n->args = list_make3($3, ver, sa);
+					n->agg_star = FALSE;
+					n->agg_distinct = FALSE;
+					n->location = @1;
+					$$ = (Node *)n;
+				}
+			| XMLSERIALIZE '(' document_or_content a_expr AS Typename ')'
+				{
+					/*
+					 * FIXME: This should be made distinguishable from
+					 * CAST (for reverse compilation at least).
+					 */
+					$$ = makeTypeCast($4, $6);
+				}
+		;
+
+/*
+ * SQL/XML support
+ */
+xml_root_version: VERSION a_expr	{ $$ = $2; }
+			| VERSION NO VALUE		{ $$ = NULL; }
+		;
+
+opt_xml_root_standalone: ',' STANDALONE YES	{ $$ = 1; }
+			| ',' STANDALONE NO				{ $$ = -1; }
+			| ',' STANDALONE NO VALUE		{ $$ = 0; }
+			| /*EMPTY*/						{ $$ = 0; }
+		;
+
+xml_attributes: XMLATTRIBUTES '(' xml_attribute_list ')' { $$ = $3; }
+		;
+
+xml_attribute_list:	xml_attribute_el					{ $$ = list_make1($1); }
+			| xml_attribute_list ',' xml_attribute_el	{ $$ = lappend($1, $3); }
+		;
+
+xml_attribute_el: a_expr AS ColLabel
+				{
+					$$ = makeNode(ResTarget);
+					$$->name = $3;
+					$$->indirection = NULL;
+					$$->val = (Node *) $1;
+
+				}
+			| a_expr
+				{
+					$$ = makeNode(ResTarget);
+					$$->name = NULL;
+					$$->indirection = NULL;
+					$$->val = (Node *) $1;				
+				}
+		;
+
+document_or_content: DOCUMENT { $$ = DOCUMENT; }
+			| CONTENT { $$ = CONTENT; }
+		;
+
+xml_whitespace_option: PRESERVE WHITESPACE { $$ = PRESERVE; }
+			| STRIP WHITESPACE { $$ = STRIP; }
+			| /*EMPTY*/ { $$ = STRIP; }
 		;
 
 /*
@@ -8562,6 +8712,7 @@ unreserved_keyword:
 			| CONCURRENTLY
 			| CONNECTION
 			| CONSTRAINTS
+			| CONTENT
 			| CONVERSION_P
 			| COPY
 			| CREATEDB
@@ -8581,6 +8732,7 @@ unreserved_keyword:
 			| DELIMITER
 			| DELIMITERS
 			| DISABLE_P
+			| DOCUMENT
 			| DOMAIN_P
 			| DOUBLE_P
 			| DROP
@@ -8640,6 +8792,7 @@ unreserved_keyword:
 			| MODE
 			| MONTH_P
 			| MOVE
+			| NAME
 			| NAMES
 			| NEXT
 			| NO
@@ -8700,12 +8853,14 @@ unreserved_keyword:
 			| SHOW
 			| SIMPLE
 			| STABLE
+			| STANDALONE
 			| START
 			| STATEMENT
 			| STATISTICS
 			| STDIN
 			| STDOUT
 			| STORAGE
+			| STRIP
 			| SUPERUSER_P
 			| SYSID
 			| SYSTEM_P
@@ -8729,13 +8884,17 @@ unreserved_keyword:
 			| VALID
 			| VALIDATOR
 			| VARYING
+			| VERSION
 			| VIEW
+			| VALUE
 			| VOLATILE
+			| WHITESPACE
 			| WITH
 			| WITHOUT
 			| WORK
 			| WRITE
 			| YEAR_P
+			| YES
 			| ZONE
 		;
 
@@ -8788,6 +8947,14 @@ col_name_keyword:
 			| TRIM
 			| VALUES
 			| VARCHAR
+			| XMLATTRIBUTES
+			| XMLELEMENT
+			| XMLCONCAT
+			| XMLFOREST
+			| XMLPARSE
+			| XMLPI
+			| XMLROOT
+			| XMLSERIALIZE
 		;
 
 /* Function identifier --- keywords that can be function names.
@@ -9322,6 +9489,17 @@ doNegateFloat(Value *v)
 	}
 }
 
+static Node *
+makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args)
+{
+	XmlExpr *x = makeNode(XmlExpr);
+	x->op = op;
+	x->name = name;
+	x->named_args = named_args;
+	x->args = args;
+	return (Node *) x;
+}
+
 /*
  * Must undefine base_yylex before including scan.c, since we want it
  * to create the function base_yylex not filtered_base_yylex.

src/backend/parser/keywords.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/keywords.c,v 1.177 2006/10/07 21:51:02 petere Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/keywords.c,v 1.178 2006/12/21 16:05:14 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -89,6 +89,7 @@ static const ScanKeyword ScanKeywords[] = {
 	{"connection", CONNECTION},
 	{"constraint", CONSTRAINT},
 	{"constraints", CONSTRAINTS},
+	{"content", CONTENT},
 	{"conversion", CONVERSION_P},
 	{"convert", CONVERT},
 	{"copy", COPY},
@@ -123,6 +124,7 @@ static const ScanKeyword ScanKeywords[] = {
 	{"disable", DISABLE_P},
 	{"distinct", DISTINCT},
 	{"do", DO},
+	{"document", DOCUMENT},
 	{"domain", DOMAIN_P},
 	{"double", DOUBLE_P},
 	{"drop", DROP},
@@ -218,6 +220,7 @@ static const ScanKeyword ScanKeywords[] = {
 	{"mode", MODE},
 	{"month", MONTH_P},
 	{"move", MOVE},
+	{"name", NAME},
 	{"names", NAMES},
 	{"national", NATIONAL},
 	{"natural", NATURAL},
@@ -314,6 +317,7 @@ static const ScanKeyword ScanKeywords[] = {
 	{"smallint", SMALLINT},
 	{"some", SOME},
 	{"stable", STABLE},
+	{"standalone", STANDALONE},
 	{"start", START},
 	{"statement", STATEMENT},
 	{"statistics", STATISTICS},
@@ -321,6 +325,7 @@ static const ScanKeyword ScanKeywords[] = {
 	{"stdout", STDOUT},
 	{"storage", STORAGE},
 	{"strict", STRICT_P},
+	{"strip", STRIP},
 	{"substring", SUBSTRING},
 	{"superuser", SUPERUSER_P},
 	{"symmetric", SYMMETRIC},
@@ -357,19 +362,31 @@ static const ScanKeyword ScanKeywords[] = {
 	{"vacuum", VACUUM},
 	{"valid", VALID},
 	{"validator", VALIDATOR},
+	{"value", VALUE},
 	{"values", VALUES},
 	{"varchar", VARCHAR},
 	{"varying", VARYING},
 	{"verbose", VERBOSE},
+	{"version", VERSION},
 	{"view", VIEW},
 	{"volatile", VOLATILE},
 	{"when", WHEN},
 	{"where", WHERE},
+	{"whitespace", WHITESPACE},
 	{"with", WITH},
 	{"without", WITHOUT},
 	{"work", WORK},
 	{"write", WRITE},
+	{"xmlattributes", XMLATTRIBUTES},
+	{"xmlconcat", XMLCONCAT},
+	{"xmlelement", XMLELEMENT},
+	{"xmlforest", XMLFOREST},
+	{"xmlparse", XMLPARSE},
+	{"xmlpi", XMLPI},
+	{"xmlroot", XMLROOT},
+	{"xmlserialize", XMLSERIALIZE},
 	{"year", YEAR_P},
+	{"yes", YES},
 	{"zone", ZONE},
 };
 

src/backend/parser/parse_coerce.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_coerce.c,v 2.147 2006/12/10 22:13:26 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_coerce.c,v 2.148 2006/12/21 16:05:14 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -919,6 +919,46 @@ coerce_to_bigint(ParseState *pstate, Node *node,
 	return node;
 }
 
+/*
+ * coerce_to_xml()
+ *		Coerce an argument of a construct that requires xml input.
+ *		Also check that input is not a set.
+ *
+ * Returns the possibly-transformed node tree.
+ *
+ * As with coerce_type, pstate may be NULL if no special unknown-Param
+ * processing is wanted.
+ */
+Node *
+coerce_to_xml(ParseState *pstate, Node *node,
+				 const char *constructName)
+{
+	Oid			inputTypeId = exprType(node);
+
+	if (inputTypeId != XMLOID)
+	{
+		node = coerce_to_target_type(pstate, node, inputTypeId,
+									 XMLOID, -1,
+									 COERCION_ASSIGNMENT,
+									 COERCE_IMPLICIT_CAST);
+		if (node == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+			/* translator: first %s is name of a SQL construct, eg LIMIT */
+					 errmsg("argument of %s must be type xml, not type %s",
+							constructName, format_type_be(inputTypeId))));
+	}
+
+	if (expression_returns_set(node))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+		/* translator: %s is name of a SQL construct, eg LIMIT */
+				 errmsg("argument of %s must not return a set",
+						constructName)));
+
+	return node;
+}
+
 
 /* select_common_type()
  *		Determine the common supertype of a list of input expression types.

src/backend/parser/parse_expr.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.199 2006/12/10 22:13:26 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.200 2006/12/21 16:05:14 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -33,6 +33,7 @@
 #include "parser/parse_type.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
+#include "utils/xml.h"
 
 
 bool		Transform_null_equals = false;
@@ -55,6 +56,7 @@ static Node *transformArrayExpr(ParseState *pstate, ArrayExpr *a);
 static Node *transformRowExpr(ParseState *pstate, RowExpr *r);
 static Node *transformCoalesceExpr(ParseState *pstate, CoalesceExpr *c);
 static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
+static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformColumnRef(ParseState *pstate, ColumnRef *cref);
 static Node *transformWholeRowRef(ParseState *pstate, char *schemaname,
@@ -232,6 +234,10 @@ transformExpr(ParseState *pstate, Node *expr)
 			result = transformBooleanTest(pstate, (BooleanTest *) expr);
 			break;
 
+		case T_XmlExpr:
+			result = transformXmlExpr(pstate, (XmlExpr *) expr);
+			break;
+
 			/*********************************************
 			 * Quietly accept node types that may be presented when we are
 			 * called on an already-transformed tree.
@@ -1409,6 +1415,56 @@ transformBooleanTest(ParseState *pstate, BooleanTest *b)
 	return (Node *) b;
 }
 
+static Node *
+transformXmlExpr(ParseState *pstate, XmlExpr *x)
+{
+	ListCell	*lc;
+	XmlExpr *newx = makeNode(XmlExpr);
+
+	newx->op = x->op;
+	if (x->name)
+		newx->name = map_sql_identifier_to_xml_name(x->name, false);
+	else
+		newx->name = NULL;
+
+	foreach(lc, x->named_args)
+	{
+		ResTarget 	*r = (ResTarget *) lfirst(lc);
+		Node 		*expr = transformExpr(pstate, r->val);
+		char 		*argname = NULL;
+
+		if (r->name)
+			argname = map_sql_identifier_to_xml_name(r->name, false);
+		else if (IsA(r->val, ColumnRef))
+			argname = map_sql_identifier_to_xml_name(FigureColname(r->val), true);
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 x->op == IS_XMLELEMENT
+					 ? errmsg("unnamed attribute value must be a column reference")
+					 : errmsg("unnamed element value must be a column reference")));
+
+		newx->named_args = lappend(newx->named_args, 
+								   makeTargetEntry((Expr *) expr, 0, argname, false)); 
+	}
+
+	foreach(lc, x->args)
+	{
+		Node	   *e = (Node *) lfirst(lc);
+		Node	   *newe;
+
+		newe = coerce_to_xml(pstate, transformExpr(pstate, e),
+							 (x->op == IS_XMLCONCAT 
+							  ? "XMLCONCAT"
+							  : (x->op == IS_XMLELEMENT
+								 ? "XMLELEMENT"
+								 : "XMLFOREST")));
+		newx->args = lappend(newx->args, newe);
+	}
+		
+	return (Node *) newx;
+}
+
 /*
  * Construct a whole-row reference to represent the notation "relation.*".
  *
@@ -1668,6 +1724,9 @@ exprType(Node *expr)
 		case T_BooleanTest:
 			type = BOOLOID;
 			break;
+		case T_XmlExpr:
+			type = XMLOID;
+			break;
 		case T_CoerceToDomain:
 			type = ((CoerceToDomain *) expr)->resulttype;
 			break;

src/backend/parser/parse_target.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_target.c,v 1.149 2006/10/04 00:29:56 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_target.c,v 1.150 2006/12/21 16:05:14 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1315,6 +1315,21 @@ FigureColnameInternal(Node *node, char **name)
 					return 2;
 			}
 			break;
+		case T_XmlExpr:
+			/* make SQL/XML functions act like a regular function */
+			switch (((XmlExpr*) node)->op)
+			{		
+				case IS_XMLCONCAT:
+					*name = "xmlconcat";
+					return 2;
+				case IS_XMLELEMENT:
+					*name = "xmlelement";
+					return 2;
+				case IS_XMLFOREST:
+					*name = "xmlforest";
+					return 2;
+			} 
+			break;
 		default:
 			break;
 	}

src/backend/utils/adt/Makefile

 #
 # Makefile for utils/adt
 #
-# $PostgreSQL: pgsql/src/backend/utils/adt/Makefile,v 1.60 2006/04/05 22:11:55 tgl Exp $
+# $PostgreSQL: pgsql/src/backend/utils/adt/Makefile,v 1.61 2006/12/21 16:05:15 petere Exp $
 #
 
 subdir = src/backend/utils/adt
@@ -25,7 +25,7 @@ OBJS = acl.o arrayfuncs.o array_userfuncs.o arrayutils.o bool.o \
 	tid.o timestamp.o varbit.o varchar.o varlena.o version.o xid.o \
 	network.o mac.o inet_net_ntop.o inet_net_pton.o \
 	ri_triggers.o pg_lzcompress.o pg_locale.o formatting.o \
-	ascii.o quote.o pgstatfuncs.o encode.o dbsize.o genfile.o
+	ascii.o quote.o pgstatfuncs.o encode.o dbsize.o genfile.o xml.o
 
 like.o: like.c like_match.c
 

src/backend/utils/adt/ruleutils.c

@@ -2,7 +2,7 @@
  * ruleutils.c	- Functions to convert stored expressions/querytrees
  *				back to source text
  *
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.235 2006/11/10 22:59:29 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.236 2006/12/21 16:05:15 petere Exp $
  **********************************************************************/
 
 #include "postgres.h"
@@ -2988,6 +2988,7 @@ isSimpleNode(Node *node, Node *parentNode, int prettyFlags)
 		case T_CoalesceExpr:
 		case T_MinMaxExpr:
 		case T_NullIfExpr:
+		case T_XmlExpr:
 		case T_Aggref:
 		case T_FuncExpr:
 			/* function-like: name(..) or name[..] */
@@ -3096,6 +3097,7 @@ isSimpleNode(Node *node, Node *parentNode, int prettyFlags)
 				case T_CoalesceExpr:	/* own parentheses */
 				case T_MinMaxExpr:		/* own parentheses */
 				case T_NullIfExpr:		/* other separators */
+				case T_XmlExpr:			/* own parentheses */
 				case T_Aggref:	/* own parentheses */
 				case T_CaseExpr:		/* other separators */
 					return true;
@@ -3144,6 +3146,7 @@ isSimpleNode(Node *node, Node *parentNode, int prettyFlags)
 				case T_CoalesceExpr:	/* own parentheses */
 				case T_MinMaxExpr:		/* own parentheses */
 				case T_NullIfExpr:		/* other separators */
+				case T_XmlExpr:			/* own parentheses */
 				case T_Aggref:	/* own parentheses */
 				case T_CaseExpr:		/* other separators */
 					return true;
@@ -3845,6 +3848,28 @@ get_rule_expr(Node *node, deparse_context *context,
 			}
 			break;
 
+		case T_XmlExpr:
+			{
+				XmlExpr *xexpr = (XmlExpr *) node;
+
+				switch (xexpr->op)
+				{
+					case IS_XMLCONCAT:
+						appendStringInfo(buf, "XMLCONCAT(");
+						break;
+					case IS_XMLELEMENT:
+						appendStringInfo(buf, "XMLELEMENT(");
+						break;
+					case IS_XMLFOREST:
+						appendStringInfo(buf, "XMLFOREST(");
+						break;
+				}
+				get_rule_expr((Node *) xexpr->named_args, context, true);
+				get_rule_expr((Node *) xexpr->args, context, true);
+				appendStringInfoChar(buf, ')');
+			}
+			break;
+
 		case T_CoerceToDomain:
 			{
 				CoerceToDomain *ctest = (CoerceToDomain *) node;

src/backend/utils/mb/mbutils.c

@@ -4,7 +4,7 @@
  * (currently mule internal code (mic) is used)
  * Tatsuo Ishii
  *
- * $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.59 2006/10/04 00:30:02 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.60 2006/12/21 16:05:15 petere Exp $
  */
 #include "postgres.h"
 
@@ -599,7 +599,7 @@ void
 SetDatabaseEncoding(int encoding)
 {
 	if (!PG_VALID_BE_ENCODING(encoding))
-		elog(ERROR, "invalid database encoding");
+		elog(ERROR, "invalid database encoding: %d", encoding);
 
 	DatabaseEncoding = &pg_enc2name_tbl[encoding];
 	Assert(DatabaseEncoding->encoding == encoding);

src/include/catalog/pg_cast.h

@@ -10,7 +10,7 @@
  *
  * Copyright (c) 2002-2006, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_cast.h,v 1.26 2006/03/05 15:58:54 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_cast.h,v 1.27 2006/12/21 16:05:15 petere Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -300,6 +300,8 @@ DATA(insert ( 1266	 25  939 i ));
 DATA(insert (	25 1266  938 e ));
 DATA(insert ( 1700	 25 1688 i ));
 DATA(insert (	25 1700 1686 e ));
+DATA(insert (  142   25    0 e ));
+DATA(insert (   25  142	2896 e ));
 
 /*
  * Cross-category casts to and from VARCHAR
@@ -338,6 +340,8 @@ DATA(insert ( 1266 1043  939 a ));
 DATA(insert ( 1043 1266  938 e ));
 DATA(insert ( 1700 1043 1688 a ));
 DATA(insert ( 1043 1700 1686 e ));
+DATA(insert (  142 1043    0 e ));
+DATA(insert ( 1043  142 2896 e ));
 
 /*
  * Cross-category casts to and from BPCHAR
@@ -377,6 +381,7 @@ DATA(insert ( 1266 1042  939 a ));
 DATA(insert ( 1042 1266  938 e ));
 DATA(insert ( 1700 1042 1688 a ));
 DATA(insert ( 1042 1700 1686 e ));
+DATA(insert (  142 1042    0 e ));
 
 /*
  * Length-coercion functions

src/include/catalog/pg_proc.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.430 2006/12/06 18:06:47 neilc Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.431 2006/12/21 16:05:15 petere Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -3976,6 +3976,26 @@ DESCR("release shared advisory lock");
 DATA(insert OID = 2892 (  pg_advisory_unlock_all		PGNSP PGUID 12 f f t f v 0 2278 "" _null_ _null_ _null_ pg_advisory_unlock_all - _null_ ));
 DESCR("release all advisory locks");
 
+/* XML support */
+DATA(insert OID = 2893 (  xml_in		   PGNSP PGUID 12 f f t f i 1 142 "2275" _null_ _null_ _null_ xml_in - _null_ ));
+DESCR("I/O");
+DATA(insert OID = 2894 (  xml_out		   PGNSP PGUID 12 f f t f i 1 2275 "142" _null_ _null_ _null_ xml_out - _null_ ));
+DESCR("I/O");
+DATA(insert OID = 2895 (  xmlcomment	   PGNSP PGUID 12 f f t f i 1 142 "25" _null_ _null_ _null_ xmlcomment - _null_ ));
+DESCR("generate an XML comment");
+DATA(insert OID = 2896 (  xmlparse		   PGNSP PGUID 12 f f t f i 1 142 "25" _null_ _null_ _null_ xmlparse - _null_ ));
+DESCR("perform a non-validating parse of a character string to produce an XML value");
+DATA(insert OID = 2897 (  xmlparse		   PGNSP PGUID 12 f f t f i 3 142 "25 16 16" _null_ _null_ _null_ xmlparse - _null_ ));
+DESCR("perform a non-validating parse of a character string to produce an XML value");
+DATA(insert OID = 2898 (  xmlpi			   PGNSP PGUID 12 f f t f i 1 142 "19" _null_ _null_ _null_ xmlpi - _null_ ));
+DESCR("generate an XML processing instruction");
+DATA(insert OID = 2899 (  xmlpi			   PGNSP PGUID 12 f f t f i 2 142 "19 25" _null_ _null_ _null_ xmlpi - _null_ ));
+DESCR("generate an XML processing instruction");
+DATA(insert OID = 2900 (  xmlroot		   PGNSP PGUID 12 f f f f i 3 142 "142 25 16" _null_ _null_ _null_ xmlroot - _null_ ));
+DESCR("create an XML value by modifying the properties of the XML root information item of another XML value");
+DATA(insert OID = 2901 (  xmlvalidate 	   PGNSP PGUID 12 f f t f i 2 16 "142 25" _null_ _null_ _null_ xmlvalidate - _null_ ));
+DESCR("validate an XML value");
+
 /*
  * Symbolic values for provolatile column: these indicate whether the result
  * of a function is dependent *only* on the values of its explicit arguments,

src/include/catalog/pg_type.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_type.h,v 1.172 2006/10/04 00:30:08 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_type.h,v 1.173 2006/12/21 16:05:15 petere Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -316,6 +316,10 @@ DATA(insert OID = 83 (	pg_class		PGNSP PGUID -1 f c t \054 1259 0 record_in reco
 #define PG_CLASS_RELTYPE_OID 83
 
 /* OIDS 100 - 199 */
+DATA(insert OID = 142 ( xml		   PGNSP PGUID -1 f b t \054 0 0 xml_in xml_out - - - i x f 0 -1 0 _null_ _null_ ));
+DESCR("XML content");
+#define XMLOID 142
+DATA(insert OID = 143 ( _xml	   PGNSP PGUID -1 f b t \054 0 142 array_in array_out array_recv array_send - i x f 0 -1 0 _null_ _null_ ));
 
 /* OIDS 200 - 299 */
 

src/include/nodes/execnodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.162 2006/12/04 02:06:55 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.163 2006/12/21 16:05:16 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -723,6 +723,22 @@ typedef struct NullTestState
 	TupleDesc	argdesc;		/* tupdesc for most recent input */
 } NullTestState;
 
+/* ----------------
+ *		XmlExprState node
+ * ----------------
+ */
+typedef struct XmlExprState
+{
+	ExprState	xprstate;
+	XmlExprOp	op;
+	char	   *name;
+	List	   *named_args;
+	List	   *args;
+	Oid		   *named_args_tcache;
+	char	  **named_args_ncache;
+	Oid			arg_typeout;
+} XmlExprState;
+
 /* ----------------
  *		CoerceToDomainState node
  * ----------------

src/include/nodes/nodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.188 2006/09/28 20:51:42 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.189 2006/12/21 16:05:16 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -140,6 +140,7 @@ typedef enum NodeTag
 	T_RangeTblRef,
 	T_JoinExpr,
 	T_FromExpr,
+	T_XmlExpr,
 
 	/*
 	 * TAGS FOR EXPRESSION STATE NODES (execnodes.h)
@@ -168,6 +169,7 @@ typedef enum NodeTag
 	T_NullTestState,
 	T_CoerceToDomainState,
 	T_DomainConstraintState,
+	T_XmlExprState,
 
 	/*
 	 * TAGS FOR PLANNER NODES (relation.h)

src/include/nodes/primnodes.h

@@ -10,7 +10,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/primnodes.h,v 1.118 2006/12/10 22:13:27 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/primnodes.h,v 1.119 2006/12/21 16:05:16 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -765,6 +765,26 @@ typedef struct BooleanTest
 	BoolTestType booltesttype;	/* test type */
 } BooleanTest;
 
+/*
+ * XmlExpr - holder for SQL/XML functions XMLCONCAT,
+ * XMLELEMENT, XMLFOREST
+ */
+typedef enum XmlExprOp
+{
+	IS_XMLCONCAT,
+	IS_XMLELEMENT,
+	IS_XMLFOREST,
+} XmlExprOp;
+
+typedef struct XmlExpr
+{
+	Expr		xpr;
+	XmlExprOp	op;				/* xml expression type */
+	char	   *name;			/* element name */
+	List	   *named_args;
+	List	   *args;
+} XmlExpr;
+
 /*
  * CoerceToDomain
  *

src/include/parser/parse_coerce.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/parser/parse_coerce.h,v 1.66 2006/10/04 00:30:09 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/parser/parse_coerce.h,v 1.67 2006/12/21 16:05:16 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -59,6 +59,8 @@ extern Node *coerce_to_integer(ParseState *pstate, Node *node,
 				  const char *constructName);
 extern Node *coerce_to_bigint(ParseState *pstate, Node *node,
 				 const char *constructName);
+extern Node *coerce_to_xml(ParseState *pstate, Node *node,
+				 const char *constructName);
 
 extern Oid	select_common_type(List *typeids, const char *context);
 extern Node *coerce_to_common_type(ParseState *pstate, Node *node,

src/include/pg_config.h.in

@@ -251,6 +251,9 @@
 /* Define to 1 if you have the `wldap32' library (-lwldap32). */
 #undef HAVE_LIBWLDAP32
 
+/* Define to 1 if you have the `xml2' library (-lxml2). */
+#undef HAVE_LIBXML2
+
 /* Define to 1 if you have the `z' library (-lz). */
 #undef HAVE_LIBZ
 
@@ -627,6 +630,9 @@
 /* Define to 1 to build with LDAP support. (--with-ldap) */
 #undef USE_LDAP
 
+/* Define to 1 to build with XML support. (--with-libxml) */
+#undef USE_LIBXML
+
 /* Define to select named POSIX semaphores. */
 #undef USE_NAMED_POSIX_SEMAPHORES
 

src/include/utils/errcodes.h

@@ -11,7 +11,7 @@
  *
  * Copyright (c) 2003-2006, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.20 2006/06/16 23:29:26 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.21 2006/12/21 16:05:16 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -148,6 +148,10 @@
 #define ERRCODE_INVALID_BINARY_REPRESENTATION	MAKE_SQLSTATE('2','2', 'P','0','3')
 #define ERRCODE_BAD_COPY_FILE_FORMAT		MAKE_SQLSTATE('2','2', 'P','0','4')
 #define ERRCODE_UNTRANSLATABLE_CHARACTER	MAKE_SQLSTATE('2','2', 'P','0','5')
+#define ERRCODE_INVALID_XML_DOCUMENT			MAKE_SQLSTATE('2', '2', '0', '0', 'M')
+#define ERRCODE_INVALID_XML_CONTENT			MAKE_SQLSTATE('2', '2', '0', '0', 'N')
+#define ERRCODE_INVALID_XML_COMMENT			MAKE_SQLSTATE('2', '2', '0', '0', 'S')
+#define ERRCODE_INVALID_XML_PROCESSING_INSTRUCTION	MAKE_SQLSTATE('2', '2', '0', '0', 'T')
 
 /* Class 23 - Integrity Constraint Violation */
 #define ERRCODE_INTEGRITY_CONSTRAINT_VIOLATION		MAKE_SQLSTATE('2','3', '0','0','0')

src/include/utils/xml.h

+/*-------------------------------------------------------------------------
+ *
+ * xml.h
+ *	  Declarations for XML data type support.
+ *
+ *
+ * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * $PostgreSQL: pgsql/src/include/utils/xml.h,v 1.1 2006/12/21 16:05:16 petere Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef XML_H
+#define XML_H
+
+#include "fmgr.h"
+
+typedef struct varlena xmltype;
+
+#define DatumGetXmlP(X)		((xmltype *) PG_DETOAST_DATUM(X))
+
+#define PG_GETARG_XML_P(n)	DatumGetXmlP(PG_GETARG_DATUM(n))
+#define PG_RETURN_XML_P(x)	PG_RETURN_POINTER(x)
+
+extern Datum xml_in(PG_FUNCTION_ARGS);
+extern Datum xml_out(PG_FUNCTION_ARGS);
+extern Datum xmlcomment(PG_FUNCTION_ARGS);
+extern Datum xmlparse(PG_FUNCTION_ARGS);
+extern Datum xmlpi(PG_FUNCTION_ARGS);
+extern Datum xmlroot(PG_FUNCTION_ARGS);
+extern Datum xmlvalidate(PG_FUNCTION_ARGS);
+
+extern char *map_sql_identifier_to_xml_name(unsigned char *ident, bool fully_escaped);
+
+#endif /* XML_H */

src/test/regress/expected/opr_sanity.out

@@ -73,7 +73,7 @@ WHERE p1.oid != p2.oid AND
 SELECT p1.oid, p1.proname, p2.oid, p2.proname
 FROM pg_proc AS p1, pg_proc AS p2
 WHERE p1.oid < p2.oid AND
-    p1.prosrc = p2.prosrc AND
+    p1.prosrc = p2.prosrc AND p1.prosrc NOT IN ('xmlparse', 'xmlpi') AND
     p1.prolang = 12 AND p2.prolang = 12 AND
     (p1.proisagg = false OR p2.proisagg = false) AND
     (p1.prolang != p2.prolang OR
@@ -285,6 +285,8 @@ WHERE c.castfunc = p.oid AND
 -- those are binary-compatible while the reverse way goes through rtrim().
 -- As of 8.2, this finds the cast from cidr to inet, because that is a
 -- trivial binary coercion while the other way goes through inet_to_cidr().
+-- As of 8.3, this finds casts from xml to text, varchar, and bpchar,
+-- because the other direction has to go through xmlparse().
 SELECT *
 FROM pg_cast c
 WHERE c.castfunc = 0 AND
@@ -297,7 +299,10 @@ WHERE c.castfunc = 0 AND
          25 |       1042 |        0 | i
        1043 |       1042 |        0 | i
         650 |        869 |        0 | i
-(3 rows)
+        142 |         25 |        0 | e
+        142 |       1043 |        0 | e
+        142 |       1042 |        0 | e
+(6 rows)
 
 -- **************** pg_operator ****************
 -- Look for illegal values in pg_operator fields.

src/test/regress/expected/prepare.out

@@ -160,7 +160,7 @@ SELECT name, statement, parameter_types FROM pg_prepared_statements
       : \x09ten = $3::bigint OR true = $4 OR oid = $5 OR odd = $6::int);   
  q5   | PREPARE q5(int, text) AS                                         | {integer,text}
       : \x09SELECT * FROM tenk1 WHERE unique1 = $1 OR stringu1 = $2;       
- q6   | PREPARE q6 AS                                                    | {integer,name}
+ q6   | PREPARE q6 AS                                                    | {integer,"\"name\""}
       :     SELECT * FROM tenk1 WHERE unique1 = $1 AND stringu1 = $2;      
  q7   | PREPARE q7(unknown) AS                                           | {path}
       :     SELECT * FROM road WHERE thepath = $1;                         

src/test/regress/expected/xml.out

+CREATE TABLE xmltest (
+    id int,
+    data xml
+);
+INSERT INTO xmltest VALUES (1, '<value>one</value>');
+INSERT INTO xmltest VALUES (2, '<value>two</value>');
+INSERT INTO xmltest VALUES (3, '<wrong');
+ERROR:  could not parse XML data
+DETAIL:  Expected '>'
+SELECT * FROM xmltest;
+ id |        data        
+----+--------------------
+  1 | <value>one</value>
+  2 | <value>two</value>
+(2 rows)
+
+SELECT xmlcomment('test');
+ xmlcomment  
+-------------
+ <!--test-->
+(1 row)
+
+SELECT xmlcomment('-test');
+  xmlcomment  
+--------------
+ <!---test-->
+(1 row)
+
+SELECT xmlcomment('test-');
+ERROR:  invalid XML comment
+SELECT xmlcomment('--test');
+ERROR:  invalid XML comment
+SELECT xmlcomment('te st');
+  xmlcomment  
+--------------
+ <!--te st-->
+(1 row)
+
+SELECT xmlconcat(xmlcomment('hello'),
+                 xmlelement(NAME qux, 'foo'),
+                 xmlcomment('world'));
+               xmlconcat                
+----------------------------------------
+ <!--hello--><qux>foo</qux><!--world-->
+(1 row)
+
+SELECT xmlconcat('hello', 'you');
+ xmlconcat 
+-----------
+ helloyou
+(1 row)
+
+SELECT xmlconcat(1, 2);
+ERROR:  argument of XMLCONCAT must be type xml, not type integer
+SELECT xmlconcat('bad', '<syntax');
+ERROR:  could not parse XML data
+DETAIL:  Expected '>'
+SELECT xmlelement(name element,
+                  xmlattributes (1 as one, 'deuce' as two),
+                  'content');
+                   xmlelement                   
+------------------------------------------------
+ <element one="1" two="deuce">content</element>
+(1 row)
+
+SELECT xmlelement(name element,
+                  xmlattributes ('unnamed and wrong'));
+ERROR:  unnamed attribute value must be a column reference
+SELECT xmlelement(name element, xmlelement(name nested, 'stuff'));
+                xmlelement                 
+-------------------------------------------
+ <element><nested>stuff</nested></element>
+(1 row)
+
+SELECT xmlelement(name employee, xmlforest(name, age, salary as pay)) FROM emp;
+                              xmlelement                              
+----------------------------------------------------------------------
+ <employee><name>sharon</name><age>25</age><pay>1000</pay></employee>
+ <employee><name>sam</name><age>30</age><pay>2000</pay></employee>
+ <employee><name>bill</name><age>20</age><pay>1000</pay></employee>
+ <employee><name>jeff</name><age>23</age><pay>600</pay></employee>
+ <employee><name>cim</name><age>30</age><pay>400</pay></employee>
+ <employee><name>linda</name><age>19</age><pay>100</pay></employee>
+(6 rows)
+
+SELECT xmlelement(name wrong, 37);
+ERROR:  argument of XMLELEMENT must be type xml, not type integer
+SELECT xmlpi(name foo);
+  xmlpi  
+---------
+ <?foo?>
+(1 row)
+
+SELECT xmlpi(name xmlstuff);
+ERROR:  invalid XML processing instruction
+DETAIL:  XML processing instruction target name cannot start with "xml".
+SELECT xmlpi(name foo, 'bar');
+    xmlpi    
+-------------
+ <?foo bar?>
+(1 row)
+
+SELECT xmlpi(name foo, 'in?>valid');
+ERROR:  invalid XML processing instruction
+DETAIL:  XML processing instruction cannot contain "?>".
+SELECT xmlroot (
+  xmlelement (
+    name gazonk,
+    xmlattributes (
+      'val' AS name,
+      1 + 1 AS num
+    ),
+    xmlelement (
+      NAME qux,
+      'foo'
+    )
+  ),
+  version '1.0',
+  standalone yes
+);
+                                         xmlroot                                          
+------------------------------------------------------------------------------------------
+ <?xml version="1.0" standalone="yes"?><gazonk name="val" num="2"><qux>foo</qux></gazonk>
+(1 row)
+
+SELECT xmlserialize(content data as character varying) FROM xmltest;
+        data        
+--------------------
+ <value>one</value>
+ <value>two</value>
+(2 rows)
+
+-- Check mapping SQL identifier to XML name
+SELECT xmlpi(name ":::_xml_abc135.%-&_");
+                      xmlpi                      
+-------------------------------------------------
+ <?_x003A_::_x005F_xml_abc135._x0025_-_x0026__?>
+(1 row)
+
+SELECT xmlpi(name "123");
+     xmlpi     
+---------------
+ <?_x0031_23?>
+(1 row)
+

src/test/regress/expected/xml_1.out

+CREATE TABLE xmltest (
+    id int,
+    data xml
+);
+INSERT INTO xmltest VALUES (1, '<value>one</value>');
+ERROR:  no XML support in this installation
+INSERT INTO xmltest VALUES (2, '<value>two</value>');
+ERROR:  no XML support in this installation
+INSERT INTO xmltest VALUES (3, '<wrong');
+ERROR:  no XML support in this installation
+SELECT * FROM xmltest;
+ id | data 
+----+------
+(0 rows)
+
+SELECT xmlcomment('test');
+ERROR:  no XML support in this installation
+SELECT xmlcomment('-test');
+ERROR:  no XML support in this installation
+SELECT xmlcomment('test-');
+ERROR:  no XML support in this installation
+SELECT xmlcomment('--test');
+ERROR:  no XML support in this installation
+SELECT xmlcomment('te st');
+ERROR:  no XML support in this installation
+SELECT xmlconcat(xmlcomment('hello'),
+                 xmlelement(NAME qux, 'foo'),
+                 xmlcomment('world'));
+ERROR:  no XML support in this installation
+SELECT xmlconcat('hello', 'you');
+ERROR:  no XML support in this installation
+SELECT xmlconcat(1, 2);
+ERROR:  argument of XMLCONCAT must be type xml, not type integer
+SELECT xmlconcat('bad', '<syntax');
+ERROR:  no XML support in this installation
+SELECT xmlelement(name element,
+                  xmlattributes (1 as one, 'deuce' as two),
+                  'content');
+ERROR:  no XML support in this installation
+SELECT xmlelement(name element,
+                  xmlattributes ('unnamed and wrong'));
+ERROR:  no XML support in this installation
+SELECT xmlelement(name element, xmlelement(name nested, 'stuff'));
+ERROR:  no XML support in this installation
+SELECT xmlelement(name employee, xmlforest(name, age, salary as pay)) FROM emp;
+ERROR:  no XML support in this installation
+SELECT xmlelement(name wrong, 37);
+ERROR:  no XML support in this installation
+SELECT xmlpi(name foo);
+ERROR:  no XML support in this installation
+SELECT xmlpi(name xmlstuff);
+ERROR:  no XML support in this installation
+SELECT xmlpi(name foo, 'bar');
+ERROR:  no XML support in this installation
+SELECT xmlpi(name foo, 'in?>valid');
+ERROR:  no XML support in this installation
+SELECT xmlroot (
+  xmlelement (
+    name gazonk,
+    xmlattributes (
+      'val' AS name,
+      1 + 1 AS num
+    ),
+    xmlelement (
+      NAME qux,
+      'foo'
+    )
+  ),
+  version '1.0',
+  standalone yes
+);
+ERROR:  no XML support in this installation
+-- Check mapping SQL identifier to XML name
+SELECT xmlpi(name ":::_xml_abc135.%-&_");
+ERROR:  no XML support in this installation
+SELECT xmlpi(name "123");
+ERROR:  no XML support in this installation

src/test/regress/parallel_schedule

 # ----------
 # The first group of parallel test
-# $PostgreSQL: pgsql/src/test/regress/parallel_schedule,v 1.35 2006/08/30 23:34:22 tgl Exp $
+# $PostgreSQL: pgsql/src/test/regress/parallel_schedule,v 1.36 2006/12/21 16:05:16 petere Exp $
 # ----------
 test: boolean char name varchar text int2 int4 int8 oid float4 float8 bit numeric
 
@@ -75,7 +75,7 @@ test: select_views portals_p2 rules foreign_key cluster dependency guc
 # The sixth group of parallel test
 # ----------
 # "plpgsql" cannot run concurrently with "rules"
-test: limit plpgsql copy2 temp domain rangefuncs prepare without_oid conversion truncate alter_table sequence polymorphism rowtypes returning
+test: limit plpgsql copy2 temp domain rangefuncs prepare without_oid conversion truncate alter_table sequence polymorphism rowtypes returning xml
 
 # run stats by itself because its delay may be insufficient under heavy load
 test: stats

src/test/regress/serial_schedule

-# $PostgreSQL: pgsql/src/test/regress/serial_schedule,v 1.33 2006/08/30 23:34:22 tgl Exp $
+# $PostgreSQL: pgsql/src/test/regress/serial_schedule,v 1.34 2006/12/21 16:05:16 petere Exp $
 # This should probably be in an order similar to parallel_schedule.
 test: boolean
 test: char
@@ -102,5 +102,6 @@ test: sequence
 test: polymorphism
 test: rowtypes
 test: returning
+test: xml
 test: stats
 test: tablespace

src/test/regress/sql/opr_sanity.sql

@@ -76,7 +76,7 @@ WHERE p1.oid != p2.oid AND
 SELECT p1.oid, p1.proname, p2.oid, p2.proname
 FROM pg_proc AS p1, pg_proc AS p2
 WHERE p1.oid < p2.oid AND
-    p1.prosrc = p2.prosrc AND
+    p1.prosrc = p2.prosrc AND p1.prosrc NOT IN ('xmlparse', 'xmlpi') AND
     p1.prolang = 12 AND p2.prolang = 12 AND
     (p1.proisagg = false OR p2.proisagg = false) AND
     (p1.prolang != p2.prolang OR
@@ -235,6 +235,9 @@ WHERE c.castfunc = p.oid AND
 -- As of 8.2, this finds the cast from cidr to inet, because that is a
 -- trivial binary coercion while the other way goes through inet_to_cidr().
 
+-- As of 8.3, this finds casts from xml to text, varchar, and bpchar,
+-- because the other direction has to go through xmlparse().
+
 SELECT *
 FROM pg_cast c
 WHERE c.castfunc = 0 AND

src/test/regress/sql/xml.sql

+CREATE TABLE xmltest (
+    id int,
+    data xml
+);
+
+INSERT INTO xmltest VALUES (1, '<value>one</value>');
+INSERT INTO xmltest VALUES (2, '<value>two</value>');
+INSERT INTO xmltest VALUES (3, '<wrong');
+
+SELECT * FROM xmltest;
+
+
+SELECT xmlcomment('test');
+SELECT xmlcomment('-test');
+SELECT xmlcomment('test-');
+SELECT xmlcomment('--test');
+SELECT xmlcomment('te st');
+
+
+SELECT xmlconcat(xmlcomment('hello'),
+                 xmlelement(NAME qux, 'foo'),
+                 xmlcomment('world'));
+
+SELECT xmlconcat('hello', 'you');
+SELECT xmlconcat(1, 2);
+SELECT xmlconcat('bad', '<syntax');
+
+
+SELECT xmlelement(name element,
+                  xmlattributes (1 as one, 'deuce' as two),
+                  'content');
+
+SELECT xmlelement(name element,
+                  xmlattributes ('unnamed and wrong'));
+
+SELECT xmlelement(name element, xmlelement(name nested, 'stuff'));
+
+SELECT xmlelement(name employee, xmlforest(name, age, salary as pay)) FROM emp;
+
+SELECT xmlelement(name wrong, 37);
+
+
+SELECT xmlpi(name foo);
+SELECT xmlpi(name xmlstuff);
+SELECT xmlpi(name foo, 'bar');
+SELECT xmlpi(name foo, 'in?>valid');
+
+
+SELECT xmlroot (
+  xmlelement (
+    name gazonk,
+    xmlattributes (
+      'val' AS name,
+      1 + 1 AS num
+    ),
+    xmlelement (
+      NAME qux,
+      'foo'
+    )
+  ),
+  version '1.0',
+  standalone yes
+);
+
+
+SELECT xmlserialize(content data as character varying) FROM xmltest;
+
+
+-- Check mapping SQL identifier to XML name
+
+SELECT xmlpi(name ":::_xml_abc135.%-&_");
+SELECT xmlpi(name "123");