Fragmentation rotation

Release: 7.30uc2 Platform: AIX 4.3.2 Preface: I seem to recall this topic being discussed but could not find any references in the iiug archive. I have a table which is fragmented by time. I am keeping 122-123 weeks of history, one week per fragment. As time goes on I am dropping the oldest fragment and adding a new one. My understanding of fragmentation is as follows. When I insert into a fragmented table, the system goes through the dbspaces in the order of which they exist in the fragmentatoin expression. So, when adding the most recent week, the fastest insert response would occur when the most recent week was the first dbspace. When adding a fragment, the system must check all data after the fragment you are adding. This takes a long time, and I am better off just putting the fragment at the end and putting up with a slower load My fragment expressions are all mutually exclusive with no remainder being put anywhere. So I know the data in the other fragments does not have to be checked Is there somthing I am missing which will allow me to put this dbspace at the front with out the checking of all other data? Is there any release which will notice that all fragmentation expressions are mutually exclusive (in my case each has a week) week=1 in dbspace1 week=2 in dbspace2 week=3 in dbspace3 ... Will Rice ------------------------------------------------------------ This e-mail has been sent to you courtesy of OperaMail, as a free service from Opera Software, makers of the award-winning Web Browser, Opera. Visit us at http://www.opera.com/ or our portal at: http://www.myopera.com/ Your free e-mail account is waiting at: http://www.operamail.com/ ------------------------------------------------------------

William Rice wrote: > > Release: 7.30uc2 > Platform: AIX 4.3.2 > > Preface: I seem to recall this topic being discussed but could not find > any references in the iiug archive. > > I have a table which is fragmented by time. I am keeping 122-123 > weeks of history, one week per fragment. As time goes on I am dropping > the oldest fragment and adding a new one. > > My understanding of fragmentation is as follows. When I insert into > a fragmented table, the system goes through the dbspaces in the order > of which they exist in the fragmentatoin expression. So, when adding > the most recent week, the fastest insert response would occur when > the most recent week was the first dbspace. > > When adding a fragment, the system must check all data after the > fragment you are adding. This takes a long time, and I am better > off just putting the fragment at the end and putting up with a slower load > > My fragment expressions are all mutually exclusive with no remainder being > put anywhere. So I know the data in the other fragments does not have > to be checked > > Is there somthing I am missing which will allow me to put this dbspace > at the front with out the checking of all other data? > Is there any release which will notice that all fragmentation > expressions are mutually exclusive (in my case each has a week) AHH, now there is the REAL question because the answer should be yes! Version 7.31 and IDS.2000 both include new code for adding and detaching fragments that will allow you to do what you need to do with minimal overhead. > week=1 in dbspace1 > week=2 in dbspace2 > week=3 in dbspace3 > ... Art S. Kagel