2006/5/11, Jeff Eaton &lt;<a href="mailto:jeff@viapositiva.net">jeff@viapositiva.net</a>&gt;:<div><span class="gmail_quote"></span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
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<div><font face="Verdana" size="2"><span>The're useful when 
the structure of a table evolves over time -- for example, version 1.45 of 
module foo adds an index for better performance. YOu can change the original 
definition, but you'll need these additional functions to write the update_x() 
function.</span></font></div></div><div><span class="sg">
<div><font face="Verdana" size="2"><span></span></font></div></span></div></div></blockquote></div><br>Probably a 'diff' can be made to determine the difference between the current tables (if they are present) and the updated definition. The install/update system would then process the differences.
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