Analyzing Your Requirements And Source Data; Preprocessing Your Data - IBM Cognos User Manual

Analyzing Your Requirements and Source Data

To ensure that you develop an effective business intelligence model, we
recommend that you begin by carefully analyzing your users, the OLAP reports
they require, and your source data.
Use the following questions to analyze your users' OLAP reporting needs:
v What reports do users currently use? Which reports do they use most
v Does each group require different reports? Are there some reports that are
v Do users need higher-level (summary) reports, detailed drill-through reports, or
v How frequently are the measures in the report updated? How frequently do the
v How often are reports required? Can you trade off frequency to ensure
Analyze your source data, using questions such as the following:
v Does the data come from one source or many? What format is it in: flat files,
v Can you optimize existing queries by building new Cognos Transformer queries
v How many records are there? By how much do you expect the volume of data
v How much of the data is static and how much changes gradually over time?
v How much data preparation is required?
v Are linked measures from different data sources updated at the same time?
v Must you create additional data sources to accurately model your organization?
When you have answered these questions, you are ready to begin preparing your
source data for import and designing your prototype.

Preprocessing Your Data

Presort, clean, or consolidate your data to maximize reporting flexibility and
performance.
Preprocess data to achieve the following benefits:
v Presorted records are processed more quickly in Cognos Transformer.
v When you streamline your source data to contain only the information needed
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IBM Cognos Transformer Version 10.1.1: User Guide
frequently? Which reports do they use only rarely?
required by all user groups?
both?
reports themselves change? Does the frequency vary from group to group?
accuracy? For example, if your users ask for monthly reports and the data
source is refreshed weekly, the data will always be current. However, if your
users want daily reports, the data will only be up to date on the first day of the
weekly cycle.
spreadsheets, or databases? Does it need to be converted to a supported data
source type before it is imported?
using the metadata modeled in IBM Cognos packages or reports?
to increase?
Can you create different data sources for static and non-static data to support
incremental updates (an option that shortens cube creation time by appending
new data to a cube instead of recreating it)?
Ensure that the source values that feed the categories are unique and, if feasible,
that you aggregate or otherwise preprocess your data before importing it. For
more information, see "Preprocessing Your Data."
for the model, read times are faster in Cognos Transformer.