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<p class="MsoNormal">Hi All,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Gloat mode engaged….<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I had a table which was very big, it had more than the maximum integer4 (2+billion) rows and had to be partitioned 32 ways just to store the data.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">It looked like this:<o:p></o:p></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">Run_id integer4<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">Pid integer4<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">Gid integer2<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">Status integer1<o:p></o:p></span></p>
<p class="MsoNormal">For any run_id there may be as many as (and typically are as many as) 500,000 rows.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Then I got told, ’What? You’re storing that stuff! We don’t need it.’ … but after examining the code for a while I found that they did need it during a particular operational phase and then not until another process which occurs once every
6months.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">So I couldn’t remove the data. But the good news was that those processes accessed the data by run_id only.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">So I made an archive table which looked like this:<o:p></o:p></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">Run_id integer4<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">All_data long varchar<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">Tinsert ingresdate</span><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The all_data field was composed of all the old rows pid,gid,status data separated by commas and each of the original rows data separated by colons.<o:p></o:p></p>
<p class="MsoNormal">Eg. 1000780,-1,0:1000800,-1,0:1000889,-1,0:1000959,-1,0…<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">So how to extract the data when actually needed it? Enter a table procedure and the similar to regular expression pattern matching.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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