LAST Function in OBIEE
This function selects the last returned value of the expression. For example, the LAST function can calculate the value of the last day of the year.
The FIRST function is limited to defining dimension-specific aggregation rules in a repository. You cannot use it in SQL statements.
The LAST function operates at the most detailed level specified in your explicitly defined dimension. For example, if you have a time dimension defined with hierarchy levels day, month, and year, the LAST function returns the last day in each level.
You should not use the LAST function as the first dimension-specific aggregate rule. It might cause queries to bring back large numbers of rows for processing in the Oracle BI Server, causing poor performance.
When a measure is based on dimensions, and data is dense, the Oracle BI Server optimizes the SQL statements sent to the database to improve performance.
Note that you cannot nest PERIODROLLING, FIRST, and LAST functions.
expr is any expression that references at least one measure column.