Specially prepared information
maps provide a metadata layer between the nontechnical business user
and the complexities of database structure and query languages. Information
maps are created by a data source administrator in a centrally managed
location so that you can easily define a report. Authorized users
who might be more advanced can access tables and cubes directly. All
data sources contain data items, which can refer to calculations or
physical data (tables or cubes). Data items in information maps are
described in common business terms that enable both casual and professional
report authors to easily build queries that return consistent results.
Reports can include query results from more than one data source.
Each information map
includes one or more data items. For example, an information map named
Order
Information might include standard data items such
as
Order ID,
Product
ID,
Unit Cost,
Order
Date, and
Order Amount.
You decide which data items to use. You can select all of the data
items in the data source or a subset of data items.
You can also create
two types of custom data items:
-
You can calculate a new measure
that is based on one or more existing measures.
-
If the data source includes a time
hierarchy from a multidimensional data source, then you can create
one or more custom data items that are based on relative time.
In addition to explaining
how to use both standard and custom data items, this chapter explains
how to modify the query in these ways:
-
by changing the format used for
one or more data items
-
by using detail data instead of
grouped and aggregated data
-
by changing the aggregation method
used for one or more measures