OBIEE - Last/First function (Point in Time measure)

About

Function that selects the first/last returned value of the expression argument.

Syntax:

FIRST (expression)
LAST (expression)

where expression is any expression.

Limitations

You cannot use it in Logical SQL statements. It must be used in the repository.

Implementation

By default, the FIRST/LAST function operates at the most detailed level specified of all dimension.

For example, if you have:

  • a time dimension defined with hierarchy levels year, month, day
  • a geographic store dimension defined with hierarchy levels county, state, zip, store

the FIRST/LAST function returns the first/last value for the combination day/store on each level. (i.e. even if the report asks a month summary for instance).

To limit the FIRST/LAST function, you must define an dimension-specific aggregation rules in the repository.

Support

Bad Performance

You should not use the FIRST/LAST function as the first dimension-specific aggregate rule. It might cause queries to occurs on large numbers of rows.

Documentation / Reference


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