Comments on: Year-to-date alternatives

By: Peter Scott

Peter Scott — Fri, 16 Mar 2007 22:48:18 +0000

Sorry, that is not the sort of thing I would do.
I would think about using inbuilt timezone functionality within Oracle or the operating system to work this sort of thing out. You have to trust the vendor to get it right though.

By: rahman

rahman — Wed, 14 Mar 2007 05:33:23 +0000

Calculate a specific date of a year from a given date of any year and precisely find the data for daylight savings

eg. 03/11/07 is the daylight savings date for 2007 so what is the date for next year daylight savings date which is 03/09/07. Thank you

By: Peter Scott

Peter Scott — Fri, 09 Feb 2007 13:47:12 +0000

Rahman
Can you give me an example of what you mean by calculate a specific date of the year?

By: rahman

rahman — Fri, 09 Feb 2007 07:57:42 +0000

How do I calculate a specific date of the year? Is there a formula or equation to calculate it?

By: David Aldridge

David Aldridge — Thu, 23 Nov 2006 01:56:23 +0000

Michael,

the tricky parts would probably be that the optimizer would be unsure of the cardinality of the subquery, and that it might interfere with effective partition pruning.

By: Michael Smith

Michael Smith — Wed, 22 Nov 2006 13:33:09 +0000

Instead of the table of date function, how about a with clause that generates the table of dates via a connect-by query and then join that to your main query?

By: Paul James

Paul James — Fri, 18 Aug 2006 07:44:28 +0000

“What happens if I wanted to run a YDT to the 31-Jul some time in Agust?
and if I wanted to look at YTD for a date last year.”

All good points, and shows that my users don’t really use data warehousing to it’s potential.
Mainly because I wouldn’t know how to present YTD at “some point in time” via Business Objects.
We do have a (month*100)+day column so this could be used for these types of queries.

And yes the flag it does get reset at the start of every year.

By: Pete_S

Pete_S — Thu, 17 Aug 2006 18:00:33 +0000

I like these functions for stuff that is very tricky to calculate for some reason, but for simple data sets like this they have the major failing (IMHO) of obscuring the cardinality of the result set from the optimizer.
Which is of course what it does – see my next post :-)

By: David Aldridge

David Aldridge — Thu, 17 Aug 2006 17:53:20 +0000

Which suddenly gives me an idea … back in a moment …

By: Pete_S

Pete_S — Thu, 17 Aug 2006 12:09:54 +0000

Paul – sounds a nice idea but I see a few problems – true they can be worked around. Do you clear that flag at the start of a new year?

What happens if I wanted to run a YDT to the 31-Jul some time in Agust?
and if I wanted to look at YTD for a date last year.