Dr. MetaData

Thursday, October 30, 2008

Time Series Functions

BI EE has the time series functions Ago() and ToDate(). Have you ever wondered how these work? The best way to find out is to examine the SQL that is generated when a query includes these functions. The structure of the SQL is determined by the database features supported by the target database. This presentation displays what happens in the case of Oracle 10gR2 (and 11g), which are "best case" databases for these functions: How Time Series Functions Work.

posted by Kurt Wolff at 7:35 AM

2 Comments:

  • Hi Kurt,

    Sounds like an interesting presentation. I think you need to grant public access to it though, I just tried to read it and I've had to submit a read request.

    Hope the new role is working out well for you

    best regards,

    Mark

    By Anonymous Anonymous, at Oct 30, 2008, 8:30:00 AM  

  • We're trying to get the TODATE() functions to generate efficient SQL on TeraData. It seems that there are several ROW_NUMBER() OVER (PARTION By...) clauses being used, which TD does not like according to the TD guys on site. These clauses are unnecessary given that we've already told OBI which are the sequential keys to use - de-duping is redundant. Is there some way to prevent this from happening? Without the ROWNUMBER feature, the SQL is pure garbage - it brings transactions back non-aggregated. Any thoughts?
    Jeff

    By Anonymous Anonymous, at Nov 20, 2008, 10:14:00 AM  

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