diff --git a/.gitignore b/.gitignore
index cbc9f02..9714a91 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,4 @@ Makefile.in
 *.lo
 *.o
 *.la
+config.ini
diff --git a/Makefile.am b/Makefile.am
index 964b79e..21f0092 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,5 +1,5 @@
 
 ACLOCAL_AMFLAGS = -I build/m4
 
-SUBDIRS = src
+SUBDIRS = proxy-auth udfs
 
diff --git a/Makefile.decl b/Makefile.decl
index f9a7be6..2818033 100644
--- a/Makefile.decl
+++ b/Makefile.decl
@@ -3,13 +3,30 @@ mysql_LIBS = `mysql_config --libs`
 mysql_CFLAGS = `mysql_config --cflags`
 
 vn_mysql_libdir = /usr/lib/mysql/plugin
+
+if MYSQL8
+
+MYSQLD_SOURCE = /var/mysql/mysql-8.0.15
+vn_mysql_CFLAGS = \
+	-Wall -O3 \
+	-DMYSQL8=1 \
+	-I$(MYSQLD_SOURCE)/include \
+	-I$(MYSQLD_SOURCE) \
+	-I$(MYSQLD_SOURCE)/bld/include \
+	-I$(MYSQLD_SOURCE)libbinlogevents/export \
+	$(mysql_CFLAGS)
+
+else
+
 vn_mysql_CFLAGS = \
 	-Wall -O3 \
 	$(mysql_CFLAGS)
+
+endif
+
 vn_mysql_LDFLAGS = \
 	-no-undefined \
 	-module \
 	-avoid-version \
 	-export-dynamic \
-	$(mysql_LIBS)
-
+	$(mysql_LIBS)
\ No newline at end of file
diff --git a/README b/README
index e69de29..77301a6 100644
--- a/README
+++ b/README
@@ -0,0 +1 @@
+Take a look at README.md
\ No newline at end of file
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..d2900f1
--- /dev/null
+++ b/README.md
@@ -0,0 +1,63 @@
+# MySQL extensions
+
+This project contains an authentication plugin and functions to extend MySQL
+functionality.
+
+## Compiling
+
+Install basic tools for compiling.
+```
+$ apt-get install build-essential devscripts dh-autoreconf
+```
+
+Install MySQL and GLib development libraries.
+```
+$ apt-get install libmysqld-dev libglib2.0-dev
+```
+
+Compile and generate Debian package for MySQL 5.
+```
+$ debuild -uc -us -b
+```
+
+Compile and generate Debian package for MySQL 8.
+```
+$ debuild --set-envvar MYSQL8=TRUE -uc -us -b
+```
+
+## Installing
+
+Install Debian package.
+```
+$ dpkg -i vn-mysql_[version]_[arch].deb
+```
+
+Register plugin and functions into MySQL.
+```
+INSTALL PLUGIN proxy_auth SONAME 'proxy_auth.so';
+CREATE AGGREGATE FUNCTION minacum RETURNS INT SONAME 'minacum.so';
+CREATE AGGREGATE FUNCTION multimax RETURNS INT SONAME 'multimax.so';
+CREATE FUNCTION sql_printf RETURNS STRING SONAME 'sql_printf.so';
+```
+
+## Uninstalling
+
+Deregister plugin and functions from MySQL.
+```
+UNINSTALL PLUGIN proxy_auth;
+DROP FUNCTION IF EXISTS minacum;
+DROP FUNCTION IF EXISTS multimax;
+DROP FUNCTION IF EXISTS sql_printf;
+```
+
+## Built with
+
+ * [MySQL](https://dev.mysql.com/doc/refman/8.0/en/extending-mysql.html)
+ * [GLib](https://developer.gnome.org/glib/)
+
+## Documentation
+
+ * [Writing plugins](https://dev.mysql.com/doc/refman/8.0/en/writing-plugins.html)
+ * [Authentication plugins](https://dev.mysql.com/doc/refman/8.0/en/writing-authentication-plugins.html)
+ * [Adding UDF](https://dev.mysql.com/doc/refman/8.0/en/adding-udf.html)
+ * [GLib API reference](https://developer.gnome.org/glib/)
diff --git a/clean.sh b/clean.sh
index 95f28ab..3686253 100755
--- a/clean.sh
+++ b/clean.sh
@@ -8,6 +8,7 @@ then
 	exit 2
 fi
 
+$dir/debian/rules clean
 rm -rf $dir/build
 rm -rf $dir/configure
 rm -rf $dir/gtk-doc.make
diff --git a/configure.ac b/configure.ac
index c84600e..7d0e995 100644
--- a/configure.ac
+++ b/configure.ac
@@ -9,14 +9,15 @@ AM_INIT_AUTOMAKE()
 AM_SILENT_RULES([yes])
 
 # Check for program dependencies
-AC_PROG_CC
 AC_PROG_CXX
+AC_PROG_CC
 PKG_CHECK_MODULES([glib], [glib-2.0])
 
+AM_CONDITIONAL([MYSQL8], [test ! -z "$MYSQL8"])
+
 AC_CONFIG_FILES([
 	Makefile
-	src/Makefile
-	src/proxy-auth/Makefile
-	src/functions/Makefile
+	proxy-auth/Makefile
+	udfs/Makefile
 ])
 AC_OUTPUT
diff --git a/debian/changelog b/debian/changelog
index 690a8e9..8c40c49 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,4 +1,4 @@
-vn-mysql (1.5.0) unstable; urgency=low
+vn-mysql (1.6.0) unstable; urgency=low
 
   * Initial Release.
 
diff --git a/debian/control b/debian/control
index fe3cc5f..744f3e3 100644
--- a/debian/control
+++ b/debian/control
@@ -2,13 +2,13 @@ Source: vn-mysql
 Section: misc
 Priority: extra
 Maintainer: Alejandro T. Colombini Gómez <atcolombini@verdnatura.es>
-Build-Depends: build-essential, dh-autoreconf, devscripts, libglib2.0-dev, libmysqld-dev
+Build-Depends: build-essential, dh-autoreconf, devscripts, libglib2.0-dev
 Standards-Version: 3.9.4
 Homepage: http://www.verdnatura.es
 
 Package: vn-mysql
 Architecture: any
-Depends: ${misc:Depends}, ${shlibs:Depends}, mysql-server (>= 5.5.27) | mariadb-galera-server (>= 5.5.27) | mariadb-server (>= 5.5.27), libglib2.0-0
+Depends: mysql-server (>= 5.5.27) | mariadb-server (>= 5.5.27), libglib2.0-0, ${misc:Depends}, ${shlibs:Depends}
 Description: MySQL plugins
  This package contains some useful MySQL plugins
  developed by Verdnatura.
diff --git a/doc/install.sql b/doc/install.sql
deleted file mode 100644
index e6603f2..0000000
--- a/doc/install.sql
+++ /dev/null
@@ -1,7 +0,0 @@
-
-INSTALL PLUGIN proxy_auth SONAME 'proxy_auth.so';
-
-CREATE AGGREGATE FUNCTION minacum RETURNS INT SONAME 'minacum.so';
-CREATE AGGREGATE FUNCTION multimax RETURNS INT SONAME 'multimax.so';
-CREATE FUNCTION sql_printf RETURNS STRING SONAME 'sql_printf.so';
-
diff --git a/doc/uninstall.sql b/doc/uninstall.sql
deleted file mode 100644
index 3416aab..0000000
--- a/doc/uninstall.sql
+++ /dev/null
@@ -1,7 +0,0 @@
-
-UNINSTALL PLUGIN proxy_auth;
-
-DROP FUNCTION IF EXISTS minacum;
-DROP FUNCTION IF EXISTS multimax;
-DROP FUNCTION IF EXISTS sql_printf;
-
diff --git a/src/proxy-auth/Makefile.am b/proxy-auth/Makefile.am
similarity index 94%
rename from src/proxy-auth/Makefile.am
rename to proxy-auth/Makefile.am
index c34ccbc..13f5f41 100644
--- a/src/proxy-auth/Makefile.am
+++ b/proxy-auth/Makefile.am
@@ -7,7 +7,7 @@ proxy_auth_data_DATA = \
 	proxy-auth.ini
 
 proxy_auth_LTLIBRARIES = proxy_auth.la
-proxy_auth_la_SOURCES = proxy-auth.c
+proxy_auth_la_SOURCES = proxy-auth.cc
 proxy_auth_la_LIBADD = \
 	$(glib_LIBS) \
 	$(vn_mysql_LIBS)
diff --git a/src/proxy-auth/proxy-auth.c b/proxy-auth/proxy-auth.cc
similarity index 84%
rename from src/proxy-auth/proxy-auth.c
rename to proxy-auth/proxy-auth.cc
index 7cedc37..d74cdf5 100644
--- a/src/proxy-auth/proxy-auth.c
+++ b/proxy-auth/proxy-auth.cc
@@ -1,10 +1,10 @@
 /*
- * Copyright (C) 2013 - Alejandro T. Colombini
+ * Copyright(C) 2013 - Alejandro T. Colombini
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
+ *(at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -15,21 +15,29 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#define MYSQL_ABI_CHECK
-
+#include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <glib-unix.h>
+
+#ifndef MYSQL8
+#define MYSQL_ABI_CHECK
+#endif
+
+//#include <stdbool.h>
 #include <mysql.h>
 #include <mysql/errmsg.h>
 #include <mysql/plugin_auth.h>
 
-#include <glib-unix.h>
+#ifdef MYSQL8
+#include <ctype.h>
+#include <mysql/plugin.h>
+#endif
 
 #define CONFIG_FILE			_CONFIG_DIR"/proxy-auth.ini"
 #define SQL_FILE			_SQL_DIR"/proxy-auth.sql"
 
-typedef struct
-{
+typedef struct {
 	gboolean initialized;
 	gchar * socket;
 	gchar * host;
@@ -49,8 +57,7 @@ typedef struct
 }
 ProxyAuth;
 
-typedef struct
-{
+typedef struct {
 	MYSQL * conn;
 	gchar * user;
 	gulong user_len;
@@ -60,8 +67,7 @@ typedef struct
 RegexData;
 
 ProxyAuth *
-proxy_auth_new()
-{
+proxy_auth_new() {
 	ProxyAuth * self = g_new(ProxyAuth, 1);
 	self->initialized = FALSE;
 	g_mutex_init(&self->mutex);
@@ -69,8 +75,7 @@ proxy_auth_new()
 }
 
 void
-proxy_auth_deinit(ProxyAuth * self)
-{
+proxy_auth_deinit(ProxyAuth * self) {
 	if (!self->initialized)
 		return;
 
@@ -92,8 +97,7 @@ proxy_auth_deinit(ProxyAuth * self)
 }
 
 void
-proxy_auth_free(ProxyAuth * self)
-{
+proxy_auth_free(ProxyAuth * self) {
 	g_return_if_fail(self != NULL);
 
 	proxy_auth_deinit(self);
@@ -102,8 +106,7 @@ proxy_auth_free(ProxyAuth * self)
 }
 
 gboolean
-proxy_auth_init(ProxyAuth * self)
-{
+proxy_auth_init(ProxyAuth * self) {
 	g_return_val_if_fail(self != NULL, FALSE);
 
 	gboolean res = FALSE;
@@ -129,8 +132,7 @@ proxy_auth_init(ProxyAuth * self)
 
 	GKeyFile * key_file = g_key_file_new();
 
-	if (!g_key_file_load_from_file(key_file, CONFIG_FILE, G_KEY_FILE_NONE, &error))
-	{
+	if (!g_key_file_load_from_file(key_file, CONFIG_FILE, G_KEY_FILE_NONE, &error)) {
 		g_warning("ProxyAuth: Can't open configuration file: %s", error->message);
 		goto end;
 	}
@@ -150,8 +152,7 @@ proxy_auth_init(ProxyAuth * self)
 
 	// Reading the query template
 
-	if (!g_file_get_contents(SQL_FILE, &self->queryt, &self->queryt_len, &error))
-	{
+	if (!g_file_get_contents(SQL_FILE, &self->queryt, &self->queryt_len, &error)) {
 		g_warning("ProxyAuth: Can't read the query template: %s", error->message);
 		goto end;
 	}
@@ -159,10 +160,9 @@ proxy_auth_init(ProxyAuth * self)
 	// Creates the regular expression
 
 	self->regex = g_regex_new("#\\w+",
-		G_REGEX_OPTIMIZE | G_REGEX_MULTILINE, 0, &error);
+		(GRegexCompileFlags)(G_REGEX_OPTIMIZE | G_REGEX_MULTILINE),(GRegexMatchFlags) 0, &error);
 
-	if (error)
-	{
+	if (error) {
 		g_warning("ProxyAuth: Can't create the regex: %s", error->message);
 		goto end;
 	}
@@ -184,27 +184,22 @@ end:
 }
 
 static gboolean
-proxy_auth_regex_func(const GMatchInfo * info, GString * res, gpointer data)
-{
+proxy_auth_regex_func(const GMatchInfo * info, GString * res, gpointer data) {
 	RegexData * regex_data = (RegexData *) data;
 	gchar * match = g_match_info_fetch(info, 0);
 
 	gchar * str = NULL;
 	gulong str_len;
 
-	if (!g_strcmp0(match, "#user"))
-	{
+	if (!g_strcmp0(match, "#user")) {
 		str = regex_data->user;
 		str_len = regex_data->user_len;
-	}
-	else if (!g_strcmp0(match, "#pass"))
-	{
+	} else if (!g_strcmp0(match, "#pass")) {
 		str = regex_data->pass;
 		str_len = regex_data->pass_len;
 	}
 
-	if (str)
-	{
+	if (str) {
 		unsigned long scaped_len;
 		char escaped_str[str_len * 2 + 1];
 
@@ -216,8 +211,7 @@ proxy_auth_regex_func(const GMatchInfo * info, GString * res, gpointer data)
 				
 		g_string_append_len(res, escaped_str,(gssize) scaped_len);
 		g_string_append_c(res, '\'');
-	}
-	else
+	} else
 		g_string_append(res, match);
 
 	g_free(match);
@@ -225,8 +219,7 @@ proxy_auth_regex_func(const GMatchInfo * info, GString * res, gpointer data)
 }
 
 static gboolean
-proxy_auth_reconnect(ProxyAuth * self, MYSQL * conn)
-{
+proxy_auth_reconnect(ProxyAuth * self, MYSQL * conn) {
 	g_return_val_if_fail(self != NULL, FALSE);
 
 	gboolean connected = mysql_real_connect(conn,
@@ -240,11 +233,10 @@ proxy_auth_reconnect(ProxyAuth * self, MYSQL * conn)
 
 	self->last_error = conn_error;
 	return connected;
-}	
+}
 
 int
-proxy_auth_authenticate(ProxyAuth * self, MYSQL_PLUGIN_VIO * vio, MYSQL_SERVER_AUTH_INFO * info)
-{
+proxy_auth_authenticate(ProxyAuth * self, MYSQL_PLUGIN_VIO * vio, MYSQL_SERVER_AUTH_INFO * info) {
 	g_return_val_if_fail(self != NULL, CR_ERROR);
 
 	int res = CR_ERROR;
@@ -257,7 +249,7 @@ proxy_auth_authenticate(ProxyAuth * self, MYSQL_PLUGIN_VIO * vio, MYSQL_SERVER_A
 	int user_len = info->user_name_length;
 
 	if (info->user_name == NULL
-	&&(user_len = vio->read_packet(vio, &pkt)) < 0)
+	&& (user_len = vio->read_packet(vio, &pkt)) < 0)
 		return CR_ERROR;
 
 	if (user_len > MYSQL_USERNAME_LENGTH)
@@ -270,8 +262,7 @@ proxy_auth_authenticate(ProxyAuth * self, MYSQL_PLUGIN_VIO * vio, MYSQL_SERVER_A
 	if (pass_len < 0)
 		return CR_ERROR;
 
-	if (!pass_len || *pkt == '\0')
-	{
+	if (!pass_len || *pkt == '\0') {
 		info->password_used = PASSWORD_USED_NO;
 		return CR_ERROR;
 	}
@@ -286,19 +277,16 @@ proxy_auth_authenticate(ProxyAuth * self, MYSQL_PLUGIN_VIO * vio, MYSQL_SERVER_A
 
 	MYSQL * conn = (MYSQL *) g_async_queue_try_pop(self->conn_pool);
 	
-	if (!conn)
-	{
+	if (!conn) {
 		g_mutex_lock(&self->mutex);
 		
-		if (self->pool_size < self->max_connections)
-		{
+		if (self->pool_size < self->max_connections) {
 			self->pool_size++;
 			g_mutex_unlock(&self->mutex);
 
 			conn = mysql_init(NULL);
 
-			if (!proxy_auth_reconnect(self, conn))
-			{
+			if (!proxy_auth_reconnect(self, conn)) {
 				g_mutex_lock(&self->mutex);
 				self->pool_size--;
 				g_mutex_unlock(&self->mutex);
@@ -307,16 +295,13 @@ proxy_auth_authenticate(ProxyAuth * self, MYSQL_PLUGIN_VIO * vio, MYSQL_SERVER_A
 				conn = NULL;
 				goto end;
 			}
-		}
-		else
-		{
+		} else {
 			g_mutex_unlock(&self->mutex);
 			conn = (MYSQL *) g_async_queue_pop(self->conn_pool);
 		}
 	}
 
-	switch (mysql_errno(conn))
-	{
+	switch (mysql_errno(conn)) {
 		case CR_SERVER_LOST:
 		case CR_SERVER_GONE_ERROR:
 			if (!proxy_auth_reconnect(self, conn))
@@ -333,10 +318,9 @@ proxy_auth_authenticate(ProxyAuth * self, MYSQL_PLUGIN_VIO * vio, MYSQL_SERVER_A
 	regex_data.pass_len = pass_len;
 	
 	query = g_regex_replace_eval(self->regex,
-		self->queryt, self->queryt_len, 0, 0, proxy_auth_regex_func, &regex_data, &error);
+		self->queryt, self->queryt_len, 0,(GRegexMatchFlags) 0, proxy_auth_regex_func, &regex_data, &error);
 
-	if (error)
-	{
+	if (error) {
 		g_warning("ProxyAuth: Can't evaluate regex: %s", error->message);
 		goto end;
 	}
@@ -349,16 +333,13 @@ proxy_auth_authenticate(ProxyAuth * self, MYSQL_PLUGIN_VIO * vio, MYSQL_SERVER_A
 	MYSQL_RES * result;
 
 	if (!mysql_query(conn, query)
-	&&(result = mysql_store_result(conn)))
-	{
+	&& (result = mysql_store_result(conn))) {
 		MYSQL_ROW row = mysql_fetch_row(result);
 
-		if (row && row[0])
-		{
+		if (row && row[0]) {
 			unsigned long row_len = mysql_fetch_lengths(result)[0];
 
-			if (row_len > 0 && row_len <= MYSQL_USERNAME_LENGTH)
-			{
+			if (row_len > 0 && row_len <= MYSQL_USERNAME_LENGTH) {
 				strcpy(info->external_user, info->user_name);
 				strncpy(info->authenticated_as, row[0], row_len);
 				info->authenticated_as[row_len] = '\0';
@@ -370,8 +351,7 @@ proxy_auth_authenticate(ProxyAuth * self, MYSQL_PLUGIN_VIO * vio, MYSQL_SERVER_A
 		}
 
 		mysql_free_result(result);
-	}
-	else
+	} else
 		g_warning("ProxyAuth: Error executing query: %s", mysql_error(conn));
 end:
 	if (conn)
@@ -385,21 +365,18 @@ end:
 ProxyAuth * pauth = NULL;
 
 static int
-proxy_auth_plugin_main(MYSQL_PLUGIN_VIO * vio, MYSQL_SERVER_AUTH_INFO * info)
-{
+proxy_auth_plugin_main(MYSQL_PLUGIN_VIO * vio, MYSQL_SERVER_AUTH_INFO * info) {
 	return proxy_auth_authenticate(pauth, vio, info);
 }
 
 static int
-proxy_auth_plugin_init()
-{
+proxy_auth_plugin_init(MYSQL_PLUGIN plugin_info) {
 	pauth = proxy_auth_new();
 	return proxy_auth_init(pauth) ? 0 : 1;
 }
 
 static int
-proxy_auth_plugin_deinit()
-{
+proxy_auth_plugin_deinit(MYSQL_PLUGIN plugin_info) {
 	proxy_auth_free(pauth);
 	return 0;
 }
@@ -408,8 +385,7 @@ int
 generate_auth_string_hash(
 	char *outbuf, unsigned int *buflen,
 	const char *inbuf,
-	unsigned int inbuflen)
-{
+	unsigned int inbuflen) {
 	if (*buflen < inbuflen)
 		return 1;
 
@@ -421,8 +397,7 @@ generate_auth_string_hash(
 int
 validate_auth_string_hash(
 	char* const inbuf  __attribute__((unused)),
-	unsigned int buflen  __attribute__((unused)))
-{
+	unsigned int buflen  __attribute__((unused))) {
 	return 0;
 }
 
@@ -431,26 +406,26 @@ set_salt(
 	const char* password __attribute__((unused)),
 	unsigned int password_len __attribute__((unused)),
 	unsigned char* salt __attribute__((unused)),
-	unsigned char* salt_len)
-{
+	unsigned char* salt_len) {
 	*salt_len = 0;
 	return 0;
 }
 
 static struct st_mysql_auth
-proxy_auth_handler =
-{
+proxy_auth_handler = {
 	MYSQL_AUTHENTICATION_INTERFACE_VERSION,
 	"mysql_clear_password", // Cleartext plugin required in the client
 	proxy_auth_plugin_main,
 	generate_auth_string_hash,
 	validate_auth_string_hash,
 	set_salt,
-	AUTH_FLAG_PRIVILEGED_USER_FOR_PASSWORD_CHANGE
+	AUTH_FLAG_PRIVILEGED_USER_FOR_PASSWORD_CHANGE,
+#ifdef MYSQL8
+	NULL
+#endif
 };
 
-mysql_declare_plugin(proxy_auth)
-{
+mysql_declare_plugin(proxy_auth) {
 	MYSQL_AUTHENTICATION_PLUGIN,
 	&proxy_auth_handler,
 	"proxy_auth",
@@ -458,6 +433,9 @@ mysql_declare_plugin(proxy_auth)
 	"Proxy user authentication server-side plugin",
 	PLUGIN_LICENSE_GPL,
 	proxy_auth_plugin_init,
+#ifdef MYSQL8
+	NULL,
+#endif
 	proxy_auth_plugin_deinit,
 	0x0100, // version 1.0,
 	NULL,
diff --git a/src/proxy-auth/proxy-auth.ini b/proxy-auth/proxy-auth.ini
similarity index 100%
rename from src/proxy-auth/proxy-auth.ini
rename to proxy-auth/proxy-auth.ini
diff --git a/src/proxy-auth/proxy-auth.pstmt.c b/proxy-auth/proxy-auth.pstmt.c
similarity index 100%
rename from src/proxy-auth/proxy-auth.pstmt.c
rename to proxy-auth/proxy-auth.pstmt.c
diff --git a/src/proxy-auth/proxy-auth.sql b/proxy-auth/proxy-auth.sql
similarity index 100%
rename from src/proxy-auth/proxy-auth.sql
rename to proxy-auth/proxy-auth.sql
diff --git a/proxy-auth/test/command.sh b/proxy-auth/test/command.sh
new file mode 100755
index 0000000..52ef3da
--- /dev/null
+++ b/proxy-auth/test/command.sh
@@ -0,0 +1,4 @@
+#!/bin/bash
+
+mysql --defaults-file=config.ini --skip-column-names --enable-cleartext-plugin < query.sql
+
diff --git a/proxy-test/connect.sh b/proxy-auth/test/connect.sh
similarity index 100%
rename from proxy-test/connect.sh
rename to proxy-auth/test/connect.sh
diff --git a/proxy-test/proxy-test.sh b/proxy-auth/test/proxy-test.sh
similarity index 77%
rename from proxy-test/proxy-test.sh
rename to proxy-auth/test/proxy-test.sh
index 8ef39cd..c2da908 100755
--- a/proxy-test/proxy-test.sh
+++ b/proxy-auth/test/proxy-test.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 
-CONCURRENCY=400
-NATTEMPS=40
+CONCURRENCY=50
+NATTEMPS=500
 
 I=0
 
diff --git a/proxy-test/query.sql b/proxy-auth/test/query.sql
similarity index 100%
rename from proxy-test/query.sql
rename to proxy-auth/test/query.sql
diff --git a/proxy-test/test.sql b/proxy-auth/test/test.sql
similarity index 100%
rename from proxy-test/test.sql
rename to proxy-auth/test/test.sql
diff --git a/proxy-test/command.sh b/proxy-test/command.sh
deleted file mode 100755
index e837846..0000000
--- a/proxy-test/command.sh
+++ /dev/null
@@ -1,4 +0,0 @@
-#!/bin/bash
-
-mysql --enable-cleartext-plugin -u test-user --password=1234 < query.sql
-
diff --git a/src/Makefile.am b/src/Makefile.am
deleted file mode 100644
index dc5ef9e..0000000
--- a/src/Makefile.am
+++ /dev/null
@@ -1,4 +0,0 @@
-
-SUBDIRS = \
-	proxy-auth \
-	functions
diff --git a/src/functions/minacum.c b/src/functions/minacum.c
deleted file mode 100644
index 108228a..0000000
--- a/src/functions/minacum.c
+++ /dev/null
@@ -1,84 +0,0 @@
-#include <stdlib.h>
-#include <string.h>
-#include <mysql/mysql.h>
-
-/*
-	DROP FUNCTION minacum;
-	CREATE AGGREGATE FUNCTION minacum RETURNS INT SONAME 'minacum.so';
-*/
-
-#define GET_ARG(n) (!args->args[n]) ? 0 : *((long long*) args->args[n])
-
-typedef struct _Interval Interval;
-struct _Interval {
-	long long num;
-	long long sum;
-	Interval* next;
-};
-
-long long minacum (UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error) {
-	Interval* ival = (Interval*) initid->ptr;
-	long long num = GET_ARG(2);
-	long long min = (ival->num != num) ? 0 : 9999999;
-	long long acum = 0;
-	while (ival != NULL) {
-		acum += ival->sum;
-		if (acum < min)
-			min = acum;
-		ival = ival->next;
-	}
-	return min;
-}
-
-void minacum_add (UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error) {
-	long long num = GET_ARG(0);
-	long long amount = GET_ARG(1);	
-	Interval* ival = (Interval*) initid->ptr;
-	Interval* prev = ival;
-	while (ival != NULL && ival->num < num) {
-		prev = ival;
-		ival = ival->next;
-	}
-	if (ival == NULL || ival->num > num) {
-		Interval* new;
-		if ((new = (Interval*) malloc (sizeof (Interval)))) {
-			new->num = num;
-			new->sum = amount;
-			new->next = ival;
-			if (prev != ival)
-				prev->next = new;
-			else
-				initid->ptr = (char *) new;
-		}
-	} else
-		ival->sum += amount;
-}
-
-void minacum_clear (UDF_INIT *initid, char *is_null, char *error) {
-	Interval* ival = (Interval*) initid->ptr;
-	Interval* cur;
-	while (ival != NULL) {
-		cur = ival;
-		ival = ival->next;
-		free (cur);
-	}
-	initid->ptr = NULL;
-}
-
-my_bool minacum_init (UDF_INIT *initid, UDF_ARGS *args, char *message) {
-	if (args->arg_count == 3) {
-		args->arg_type[0] = INT_RESULT;
-		args->arg_type[1] = INT_RESULT;
-		args->arg_type[2] = INT_RESULT;
-		initid->maybe_null = 0;
-		initid->const_item = 0;
-		initid->ptr = NULL;
-		return 0;
-	} else {
-		strcpy(message, "minacum must have 3 parameters");
-		return 1;
-	}
-}
-
-void minacum_deinit (UDF_INIT *initid) {}
-
diff --git a/src/functions/multimax.c b/src/functions/multimax.c
deleted file mode 100644
index 06aaabb..0000000
--- a/src/functions/multimax.c
+++ /dev/null
@@ -1,103 +0,0 @@
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <mysql/mysql.h>
-
-#define NAME	"multimax"
-#define PARAMC	2
-
-#define DATA(ptr)	((void **) ptr)
-#define INT(ptr)	(*((long long *) ptr))
-#define DOUBLE(ptr)	(*((double *) ptr))
-
-long long multimax (UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error)
-{
-	return INT (DATA (initid->ptr)[1]);
-}
-
-void multimax_add (UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error)
-{
-	size_t set;
-	void ** data = DATA (initid->ptr);
-
-	if (args->args[0] && data[0])
-	{
-		switch (args->arg_type[0])
-		{
-			case INT_RESULT:
-				set = INT (args->args[0]) > INT (data[0]);
-				break;
-			case REAL_RESULT:
-				set = DOUBLE (args->args[0]) > DOUBLE (data[0]);
-				break;
-			default: // STRING
-				set = strcmp (args->args[0], data[0]) > 0;
-		}
-	}
-	else
-		set = data[0] == NULL;		
-	
-	if (set)
-	{
-		int n;
-
-		for (n = 0; n < PARAMC; n++)
-		{
-			free (data[n]);
-
-			switch (args->arg_type[0])
-			{
-				case INT_RESULT:
-					set = sizeof (long long);
-					data[n] = malloc (set);
-					break;
-				case REAL_RESULT:
-					set = sizeof (double);
-					data[n] = malloc (set);
-					break;
-				default: // STRING
-					set = args->lengths[0];
-					data[n] = malloc (set + 1);
-					((char *) data[n])[set] = '\0';
-			}
-
-			memcpy (data[n], args->args[n], set);
-		}		
-	}
-}
-
-void multimax_clear (UDF_INIT *initid, char *is_null, char *error)
-{
-	void ** data = DATA (initid->ptr);
-	free (data[0]);
-	free (data[1]);
-	data[0] = NULL;
-	data[1] = NULL;
-}
-
-my_bool multimax_init (UDF_INIT *initid, UDF_ARGS *args, char *message)
-{
-	if (args->arg_count == PARAMC)
-	{
-		void ** data = malloc (sizeof (void *) * 2);
-		data[0] = NULL;
-		data[1] = NULL;
-
-		args->arg_type[1] = INT_RESULT;
-		initid->ptr = (void *) data;
-		initid->maybe_null = 0;
-		initid->const_item = 0;
-		return 0;
-	}
-	else
-	{
-		sprintf (message, "%s must have %d parameters", NAME, PARAMC);
-		return 1;
-	}
-}
-
-void multimax_deinit (UDF_INIT *initid)
-{
-	free (initid->ptr);
-}
-
diff --git a/src/functions/sql_printf.c b/src/functions/sql_printf.c
deleted file mode 100644
index d3bcf27..0000000
--- a/src/functions/sql_printf.c
+++ /dev/null
@@ -1,146 +0,0 @@
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <mysql/mysql.h>
-
-#define NAME		"multimax"
-#define NPARAMS		1
-#define BLOCK_SIZE	1024
-
-typedef struct
-{
-	int * org_type;
-	char * data;
-	unsigned long len;
-	unsigned long alloc;
-}
-Buffer;
-
-static void buffer_append (Buffer *buffer, char *string, unsigned long len)
-{
-	if (!string)
-		return;
-		
-	unsigned long new_len = buffer->len + len;
-
-	if (new_len > buffer->alloc)
-	{
-		buffer->alloc = new_len + BLOCK_SIZE - (new_len % BLOCK_SIZE);
-		buffer->data = realloc (buffer->data, sizeof (char) * buffer->alloc);
-	}
-
-	strncpy (&buffer->data[buffer->len], string, len);
-	buffer->len = new_len;
-}
-
-char * sql_printf (UDF_INIT *initid, UDF_ARGS *args, char *result, unsigned long *length, char *is_null, char *error)
-{
-	int i = 1;
-	unsigned long j = 0;
-	Buffer *buffer = (Buffer *) initid->ptr;
-	char *format = args->args[0];
-	
-	if (!format)
-	{
-		*is_null = 1;
-		return NULL;
-	}
-
-	while (1)
-	{
-		char *delimiter = NULL;
-		unsigned long aux = j;
-
-		while (j < args->lengths[0] && format[j] != '%')
-			j++;
-
-		buffer_append (buffer, &format[aux], j - aux);
-
-		if (j == args->lengths[0])
-			break;
-			
-		char c = format[j+1];
-		j += 2;
-	
-		switch (c)
-		{
-			case 't':
-				delimiter = "`";
-				break;
-			case 'v':
-				if (buffer->org_type[i] == STRING_RESULT)
-					delimiter = "'";
-				break;
-			case 's':
-				break;
-			case '%':
-				buffer_append (buffer, "%", 1);
-				continue;
-			default:
-				*error = 1;
-				return NULL;
-		}
-		
-		if (i >= args->arg_count)
-		{
-			*error = 1;
-			return NULL;
-		}
-
-		char *arg = args->args[i];
-		unsigned long len = args->lengths[i];
-
-		if (!arg)
-		{
-			arg = "NULL";
-			len = strlen (arg);
-			delimiter = NULL;
-		}
-
-		buffer_append (buffer, delimiter, 1);
-		buffer_append (buffer, arg, len);
-		buffer_append (buffer, delimiter, 1);
-		i++;
-	}
-
-	*length = buffer->len;
-	return buffer->data;
-}
-
-my_bool sql_printf_init (UDF_INIT *initid, UDF_ARGS *args, char *message)
-{
-	if (args->arg_count >= NPARAMS)
-	{
-		int i;
-		Buffer *buffer = malloc (sizeof (Buffer));
-		buffer->org_type = malloc (sizeof (int) * args->arg_count);
-		buffer->alloc = BLOCK_SIZE;
-		buffer->data = malloc (sizeof (char) * buffer->alloc);
-		buffer->len = 0;
-		
-		for (i = 0; i < args->arg_count; i++)
-		{
-			buffer->org_type[i] = args->arg_type[i];
-			args->arg_type[i] = STRING_RESULT;
-		}
-
-		initid->ptr = (void *) buffer;
-		initid->maybe_null = 1;
-		initid->const_item = 0;
-		return 0;
-	}
-	else
-	{
-		sprintf (message, "%s must have at least %d parameters", NAME, NPARAMS);
-		return 1;
-	}
-}
-
-void sql_printf_deinit (UDF_INIT *initid) 
-{
-	Buffer *buffer = (Buffer *) initid->ptr;
-	free (buffer->org_type);
-	free (buffer->data);
-	free (buffer);
-}
-
diff --git a/src/functions/Makefile.am b/udfs/Makefile.am
similarity index 81%
rename from src/functions/Makefile.am
rename to udfs/Makefile.am
index 0c680d9..b63cbbd 100644
--- a/src/functions/Makefile.am
+++ b/udfs/Makefile.am
@@ -4,8 +4,9 @@ include $(top_srcdir)/Makefile.decl
 # minacum
 
 minacum_LTLIBRARIES = minacum.la
-minacum_la_SOURCES = minacum.c
+minacum_la_SOURCES = minacum.cc
 minacum_la_LIBADD = $(vn_mysql_LIBS)
+minacum_la_CPPFLAGS = $(vn_mysql_CFLAGS)
 minacum_la_CFLAGS = $(vn_mysql_CFLAGS)
 minacum_la_LDFLAGS = $(vn_mysql_LDFLAGS)
 minacumdir = $(vn_mysql_libdir)
@@ -13,18 +14,20 @@ minacumdir = $(vn_mysql_libdir)
 # sql_printf
 
 sql_printf_LTLIBRARIES = sql_printf.la
-sql_printf_la_SOURCES = sql_printf.c
+sql_printf_la_SOURCES = sql_printf.cc
 sql_printf_la_LIBADD = $(vn_mysql_LIBS)
 sql_printf_la_CFLAGS = $(vn_mysql_CFLAGS)
+sql_printf_la_CPPFLAGS = $(vn_mysql_CFLAGS)
 sql_printf_la_LDFLAGS = $(vn_mysql_LDFLAGS)
 sql_printfdir = $(vn_mysql_libdir)
 
 # multimax
 
 multimax_LTLIBRARIES = multimax.la
-multimax_la_SOURCES = multimax.c
+multimax_la_SOURCES = multimax.cc
 multimax_la_LIBADD = $(vn_mysql_LIBS)
 multimax_la_CFLAGS = $(vn_mysql_CFLAGS)
+multimax_la_CPPFLAGS = $(vn_mysql_CFLAGS)
 multimax_la_LDFLAGS = $(vn_mysql_LDFLAGS)
 multimaxdir = $(vn_mysql_libdir)
 
@@ -40,4 +43,3 @@ install-data-hook:
 	
 #$(FILE): $(SRC)
 #	gcc -shared -o $@ $< -fPIC
-
diff --git a/udfs/minacum.cc b/udfs/minacum.cc
new file mode 100644
index 0000000..b84b971
--- /dev/null
+++ b/udfs/minacum.cc
@@ -0,0 +1,108 @@
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <mysql/mysql.h>
+
+#define NAME        "minacum"
+#define N_ARGS      3
+
+#define ARG_IVAL    0
+#define ARG_NUM     1
+#define ARG_BASE    2
+
+#define INTERVAL(ptr)   ((Interval *) ptr)
+#define GET_ARG(n)      (args->args[n] == NULL ? 0 : *((long long*) args->args[n]))
+
+extern "C" {
+
+typedef struct _Interval Interval;
+struct _Interval {
+	long long num;
+	long long sum;
+	Interval* next;
+};
+
+void free_data(UDF_INIT *initid) {
+	Interval* ival = INTERVAL(initid->ptr);
+	Interval* cur;
+	while (ival != NULL) {
+		cur = ival;
+		ival = ival->next;
+		free(cur);
+	}
+	initid->ptr = NULL;
+}
+
+long long minacum(UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error) {
+	Interval* ival = INTERVAL(initid->ptr);
+	if (ival == NULL) return 0;
+
+	long long min;
+	long long base = GET_ARG(ARG_BASE);
+
+	if (ival->num == base) {
+		min = ival->sum;
+		ival = ival->next;
+	} else
+		min = 0;
+
+	long long acum = min;
+
+	while (ival != NULL) {
+		acum += ival->sum;
+		if (acum < min) min = acum;
+		ival = ival->next;
+	}
+
+	return min;
+}
+
+void minacum_add(UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error) {
+	long long num = GET_ARG(ARG_IVAL);
+	long long amount = GET_ARG(ARG_NUM);
+
+	Interval* ival = INTERVAL(initid->ptr);
+	Interval* prev = ival;
+
+	while (ival != NULL && ival->num < num) {
+		prev = ival;
+		ival = ival->next;
+	}
+
+	if (ival == NULL || ival->num > num) {
+		Interval* new_ival = INTERVAL(malloc(sizeof(Interval)));
+		new_ival->num = num;
+		new_ival->sum = amount;
+		new_ival->next = ival;
+		if (prev != ival)
+			prev->next = new_ival;
+		else
+			initid->ptr = (char *) new_ival;
+	} else
+		ival->sum += amount;
+}
+
+void minacum_clear(UDF_INIT *initid, char *is_null, char *error) {
+	free_data(initid);
+}
+
+bool minacum_init(UDF_INIT *initid, UDF_ARGS *args, char *message) {
+	if (args->arg_count == N_ARGS) {
+		args->arg_type[ARG_IVAL] = INT_RESULT;
+		args->arg_type[ARG_NUM] = INT_RESULT;
+		args->arg_type[ARG_BASE] = INT_RESULT;
+		initid->maybe_null = 0;
+		initid->const_item = 0;
+		initid->ptr = NULL;
+		return 0;
+	} else {
+		sprintf(message, "%s must have %d parameters", NAME, N_ARGS);
+		return 1;
+	}
+}
+
+void minacum_deinit(UDF_INIT *initid) {
+	free_data(initid);
+}
+
+}
diff --git a/udfs/multimax.cc b/udfs/multimax.cc
new file mode 100644
index 0000000..97bcbdb
--- /dev/null
+++ b/udfs/multimax.cc
@@ -0,0 +1,76 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <mysql/mysql.h>
+
+#define NAME        "multimax"
+#define N_ARGS      2
+
+#define ARG_MAX     0
+#define ARG_VALUE   1
+
+#define DATA(ptr)   ((Data *) ptr)
+
+extern "C" {
+
+#include "value.cc"
+
+typedef struct {
+	Value max;
+	Value value;
+}
+Data;
+
+void free_data(UDF_INIT *initid) {
+	Data* data = (Data *) initid->ptr;
+	value_set_null(&data->max);
+	value_set_null(&data->value);
+}
+
+long long multimax(UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error) {
+	Value * value = &DATA(initid->ptr)->value;
+	if (value->is_null) {
+		*is_null = 1;
+		return 0;
+	}
+	return value->val.i;
+}
+
+void multimax_add(UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error) {
+	Data *data = (Data *) initid->ptr;
+	Value max;
+	value_from_arg(&max, args, ARG_MAX);
+
+	if (value_compare(&max, &data->max) > 0) {
+		value_copy_arg(&data->max, args, ARG_MAX);
+		value_copy_arg(&data->value, args, ARG_VALUE);
+	}
+}
+
+void multimax_clear(UDF_INIT *initid, char *is_null, char *error) {
+	free_data(initid);
+}
+
+bool multimax_init(UDF_INIT *initid, UDF_ARGS *args, char *message) {
+	if (args->arg_count == N_ARGS) {
+		Data *data = DATA(malloc(sizeof(Data)));
+		value_init(&data->max);
+		value_init(&data->value);
+
+		args->arg_type[ARG_VALUE] = INT_RESULT;
+		initid->ptr = (char *) data;
+		initid->maybe_null = 1;
+		initid->const_item = 0;
+		return 0;
+	} else {
+		sprintf(message, "%s must have %d parameters", NAME, N_ARGS);
+		return 1;
+	}
+}
+
+void multimax_deinit(UDF_INIT *initid) {
+	free_data(initid);
+	free(initid->ptr);
+}
+
+}
diff --git a/udfs/sql_printf.cc b/udfs/sql_printf.cc
new file mode 100644
index 0000000..6df97d7
--- /dev/null
+++ b/udfs/sql_printf.cc
@@ -0,0 +1,135 @@
+
+#include <stdio.h>
+#include <string.h>
+#include <mysql/mysql.h>
+
+#define NAME        "sql_printf"
+#define N_ARGS      1
+#define BLOCK_SIZE  1024
+
+extern "C" {
+
+typedef struct {
+	int * org_type;
+	char * data;
+	unsigned long len;
+	unsigned long alloc;
+}
+Buffer;
+
+static void buffer_append_len(Buffer *buffer, const char *string, unsigned long len) {
+	if (!string) return;
+	unsigned long new_len = buffer->len + len;
+
+	if (new_len > buffer->alloc) {
+		buffer->alloc = new_len + BLOCK_SIZE - (new_len % BLOCK_SIZE);
+		buffer->data = (char *) realloc(buffer->data, sizeof(char) * buffer->alloc);
+	}
+
+	strncpy(&buffer->data[buffer->len], string, len);
+	buffer->len = new_len;
+}
+
+static void buffer_append(Buffer *buffer, const char *string) {
+	if (!string) return;
+	buffer_append_len(buffer, string, strlen(string));
+}
+
+char * sql_printf(UDF_INIT *initid, UDF_ARGS *args, char *result, unsigned long *length, char *is_null, char *error) {
+	unsigned int i = 1;
+	unsigned long j = 0;
+	Buffer *buffer = (Buffer *) initid->ptr;
+	char *format = args->args[0];
+	
+	if (!format) {
+		*is_null = 1;
+		return NULL;
+	}
+
+	while (1) {
+		const char *delimiter = NULL;
+		unsigned long aux = j;
+
+		while (j < args->lengths[0] && format[j] != '%')
+			j++;
+
+		buffer_append_len(buffer, &format[aux], j - aux);
+
+		if (j == args->lengths[0])
+			break;
+			
+		char c = format[j+1];
+		j += 2;
+	
+		switch (c) {
+			case 't':
+				delimiter = "`";
+				break;
+			case 'v':
+				if (buffer->org_type[i] == STRING_RESULT)
+					delimiter = "'";
+				break;
+			case 's':
+				break;
+			case '%':
+				buffer_append(buffer, "%");
+				continue;
+			default:
+				*error = 1;
+				return NULL;
+		}
+		
+		if (i >= args->arg_count) {
+			*error = 1;
+			return NULL;
+		}
+
+		char *arg = args->args[i];
+		unsigned long len = args->lengths[i];
+
+		if (arg) {
+			buffer_append(buffer, delimiter);
+			buffer_append_len(buffer, arg, len);
+			buffer_append(buffer, delimiter);
+		} else
+			buffer_append(buffer, "NULL");
+
+		i++;
+	}
+
+	*length = buffer->len;
+	return buffer->data;
+}
+
+bool sql_printf_init(UDF_INIT *initid, UDF_ARGS *args, char *message) {
+	if (args->arg_count >= N_ARGS) {
+		unsigned int i;
+		Buffer *buffer = (Buffer *) malloc(sizeof(Buffer));
+		buffer->org_type = (int *) malloc(sizeof(int) * args->arg_count);
+		buffer->alloc = BLOCK_SIZE;
+		buffer->data = (char *) malloc(sizeof(char) * buffer->alloc);
+		buffer->len = 0;
+		
+		for (i = 0; i < args->arg_count; i++) {
+			buffer->org_type[i] = args->arg_type[i];
+			args->arg_type[i] = STRING_RESULT;
+		}
+
+		initid->ptr = (char *) buffer;
+		initid->maybe_null = 1;
+		initid->const_item = 0;
+		return 0;
+	} else {
+		sprintf(message, "%s must have at least %d parameters", NAME, N_ARGS);
+		return 1;
+	}
+}
+
+void sql_printf_deinit(UDF_INIT *initid) {
+	Buffer *buffer = (Buffer *) initid->ptr;
+	free(buffer->org_type);
+	free(buffer->data);
+	free(buffer);
+}
+
+}
diff --git a/udfs/value.cc b/udfs/value.cc
new file mode 100644
index 0000000..131a8bc
--- /dev/null
+++ b/udfs/value.cc
@@ -0,0 +1,97 @@
+
+// Value handling functions
+
+#define INT(ptr)    (*((long long *) ptr))
+#define DOUBLE(ptr) (*((double *) ptr))
+#define min(a,b)    (a < b ? a : b)
+
+typedef union {
+	long long i;
+	double d;
+	char * s;
+} Val;
+
+typedef struct {
+	Val val;
+	int is_null;
+	Item_result type;
+	unsigned long len;
+	int free;
+} Value;
+
+#define value_ptr(value)    (value->is_null ? NULL : (char *) &value->val)
+
+void value_init(Value * value) {
+	value->is_null = 1;
+	value->free = 0;
+}
+
+void value_free_val(Value *value) {
+	if (value->free) free(value->val.s);
+}
+
+void value_set_null(Value *value) {
+	value_free_val(value);
+	value->is_null = 1;
+}
+
+void value_set(Value * value, UDF_ARGS *args, int arg_index, int copy) {
+	char * arg = args->args[arg_index];
+	value->free = 0;
+
+	if (arg != NULL) {
+		value->is_null = 0;
+		value->type = args->arg_type[arg_index];
+
+		switch (value->type) {
+		case INT_RESULT:
+			value->val.i = INT(arg);
+			break;
+		case REAL_RESULT:
+			value->val.d = DOUBLE(arg);
+			break;
+		default:
+			value->free = copy;
+			value->len = args->lengths[arg_index];
+			if (copy) {
+				value->val.s = (char *) malloc(value->len);
+				memcpy(value->val.s, arg, value->len);
+			} else
+				value->val.s = arg;
+		}
+	} else
+		value->is_null = 1;
+}
+
+void value_from_arg(Value * value, UDF_ARGS *args, int arg_index) {
+	value_set(value, args, arg_index, 0);
+}
+
+void value_copy_arg(Value * value, UDF_ARGS *args, int arg_index) {
+	value_free_val(value);
+	value_set(value, args, arg_index, 1);
+}
+
+int value_compare(Value *a, Value *b) {
+	int cmp;
+	double real_cmp;
+
+	if (!a->is_null && !b->is_null && a->type == b->type) {
+		switch (a->type) {
+		case INT_RESULT:
+			cmp = a->val.i - b->val.i;
+			break;
+		case REAL_RESULT: {
+			real_cmp = a->val.d - b->val.d;
+			cmp = real_cmp == 0.0 ? 0 : (real_cmp > 0.0 ? 1 : -1);
+			break;
+		}
+		default: // STRING_RESULT & DECIMAL_RESULT
+			cmp = strncmp(a->val.s, b->val.s, min(a->len, b->len));
+			if (cmp == 0) cmp = a->len - b->len;
+		}
+	} else
+		cmp = b->is_null;
+
+	return cmp;
+}