21.22. Audit table partitioning example
<div class="paragraph">
In order to determine a suitable column for the 'increasing level of relevancy',
consider a simplified example of a salary registration for an unnamed agency.
</div>
<div class="paragraph">
Currently, the salary table contains the following rows for a certain person X:
</div>
<table class="tableblock frame-all grid-all spread">
<caption class="title">Table 11. Salaries table</caption>
<colgroup>
<col style="width: 50%;">
<col style="width: 50%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top">Year</th>
<th class="tableblock halign-left valign-top">Salary (USD)</th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top">
2006
</td>
<td class="tableblock halign-left valign-top">
3300
</td>
</tr>
<tr>
<td class="tableblock halign-left valign-top">
2007
</td>
<td class="tableblock halign-left valign-top">
3500
</td>
</tr>
<tr>
<td class="tableblock halign-left valign-top">
2008
</td>
<td class="tableblock halign-left valign-top">
4000
</td>
</tr>
<tr>
<td class="tableblock halign-left valign-top">
2009
</td>
<td class="tableblock halign-left valign-top">
4500
</td>
</tr>
</tbody>
</table>
<div class="paragraph">
The salary for the current fiscal year (2010) is unknown.
The agency requires that all changes in registered salaries for a fiscal year are recorded (i.e. an audit trail).
The rationale behind this is that decisions made at a certain date are based on the registered salary at that time.
And at any time it must be possible reproduce the reason why a certain decision was made at a certain date.
</div>
<div class="paragraph">
The following audit information is available, sorted on in order of occurrence:
</div>
<table class="tableblock frame-all grid-all spread">
<caption class="title">Table 12. Salaries - audit table</caption>
<colgroup>
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 20%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top">Year</th>
<th class="tableblock halign-left valign-top">Revision type</th>
<th class="tableblock halign-left valign-top">Revision timestamp</th>
<th class="tableblock halign-left valign-top">Salary (USD)</th>
<th class="tableblock halign-left valign-top">End revision timestamp</th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top">
2006
</td>
<td class="tableblock halign-left valign-top">
ADD
</td>
<td class="tableblock halign-left valign-top">
2007-04-01
</td>
<td class="tableblock halign-left valign-top">
3300
</td>
<td class="tableblock halign-left valign-top">
null
</td>
</tr>
<tr>
<td class="tableblock halign-left valign-top">
2007
</td>
<td class="tableblock halign-left valign-top">
ADD
</td>
<td class="tableblock halign-left valign-top">
2008-04-01
</td>
<td class="tableblock halign-left valign-top">
35
</td>
<td class="tableblock halign-left valign-top">
2008-04-02
</td>
</tr>
<tr>
<td class="tableblock halign-left valign-top">
2007
</td>
<td class="tableblock halign-left valign-top">
MOD
</td>
<td class="tableblock halign-left valign-top">
2008-04-02
</td>
<td class="tableblock halign-left valign-top">
3500
</td>
<td class="tableblock halign-left valign-top">
null
</td>
</tr>
<tr>
<td class="tableblock halign-left valign-top">
2008
</td>
<td class="tableblock halign-left valign-top">
ADD
</td>
<td class="tableblock halign-left valign-top">
2009-04-01
</td>
<td class="tableblock halign-left valign-top">
3700
</td>
<td class="tableblock halign-left valign-top">
2009-07-01
</td>
</tr>
<tr>
<td class="tableblock halign-left valign-top">
2008
</td>
<td class="tableblock halign-left valign-top">
MOD
</td>
<td class="tableblock halign-left valign-top">
2009-07-01
</td>
<td class="tableblock halign-left valign-top">
4100
</td>
<td class="tableblock halign-left valign-top">
2010-02-01
</td>
</tr>
<tr>
<td class="tableblock halign-left valign-top">
2008
</td>
<td class="tableblock halign-left valign-top">
MOD
</td>
<td class="tableblock halign-left valign-top">
2010-02-01
</td>
<td class="tableblock halign-left valign-top">
4000
</td>
<td class="tableblock halign-left valign-top">
null
</td>
</tr>
<tr>
<td class="tableblock halign-left valign-top">
2009
</td>
<td class="tableblock halign-left valign-top">
ADD
</td>
<td class="tableblock halign-left valign-top">
2010-04-01
</td>
<td class="tableblock halign-left valign-top">
4500
</td>
<td class="tableblock halign-left valign-top">
null
</td>
</tr>
</tbody>
</table>
</div>
<div class="sect2">