<?xml version="1.0" encoding="ISO-8859-1"?>
<slide>
	<title>Denormalization</title>
	<subtitle>Update Problems</subtitle>

	<image filename="denormalization2.png"/>
	<blurb>&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;</blurb>
	<blurb>If some airport changes name, you need to run multiple updates:</blurb>
<break/>
  <example><![CDATA[UPDATE airport_code
	SET airfield_name = 'Montreal Pierre Trudeau'
	WHERE code = 'YUL';

UPDATE flight_denorm
	SET from_airfield_name = 'Montreal Pierre Trudeau'
	WHERE from_airport = 'YUL';

UPDATE flight_denorm
	SET to_airfield_name = 'Montreal Pierre Trudeau'
	WHERE to_airport = 'YUL';]]></example>

</slide>

