Facts
What is fact
extension?
You can use level
extensions to change a fact level, which is a set of attributes that represent
the lowest level of detail at which the fact exists in the warehouse.
Level
extensions define how facts can be extended, lowered, or disallowed to other
facts across the schema.
What is fact
degradation?
When facts exist at
a higher level than the report display level, you must specify how the Engine
degrades the data to the lower level. When you lower the level at which a fact
is reported, you are using degradation.
Types of facts
Simple facts
A simple fact is made
up of one or more fact expressions. With a simple fact definition, you can
define a fact as a column, constant, or simple expression.
Implicit
facts
An implicit fact is a virtual or
constant fact that does not physically exist in the database because it is
created at the application level.
Derived facts
A derived fact has its value
determined by an expression that combines two or more columns in a database to
create a new column.
Metrics
What are different
types of metrics?
Simple : Simple metrics combine
aggregate operators with fact columns or attributes.
Nested: Metrics that perform multiple
aggregations by placing one calculation formula inside another
Compound : A compound metric is a
combination of expressions that, through the use of functions, are themselves
metrics.
Derived
What is Base
Formula?
Use a simple expression as a
base formula to facilitate the creation of more complex metrics.
What is smart
metrics?
Compound metrics are the ones that
are derived by some specific expression involving the different simple metrics.
Eg, Total( profit/units Sold). Smart metrics is when the compound metric is
calculated with the help of subtotal calculations for every element inside the
compound metric. For the above example the smart metric computation can be
Total(profit)/Total(Sold).
What is level
metric?
Level metrics are advanced metrics
which are set to be evaluated at a specified attribute level. These are
required when in the same report you need to roll up a metric at two different
levels side by side. Example is comparison of “Revenue from a Region” to
“Revenue from a Country”. Here Region and Country are the two different
levels.
The level of a metric, also referred
to as dimensionality, allows you to determine the attribute level at which the
metric is calculated.
Default – Report Level
The elements needed to specify
a level for a metric
Target
- Attribute level at which the metric
Grouping - Determines the
metric aggregation.
Filtering - governs
the relationship between the
report filter and the calculation of
the metric.
What is
purpose of having conditionality in metrics?
Conditionality associates a filter to
the metric calculation. This is an optional component.
What are the
different components of metrics?
The formula defines the data to be
used and the calculations to be performed on the data. The outermost formula
must be a group function.
The level, or dimensionality,
determines the level at which to perform the metric calculation. For example,
you can choose to calculate at the month level or year level.
Conditionality associates a filter to
the metric calculation. This is an optional component.
The transformation applies offset
values, such as “four months ago,” to the selected attributes. This is also an
optional component.
What is the
purpose of transformation in Metrics? Types of transformation.
It encapsulates a business rule used
to compare results of different time periods.Transformations are used in the
definition of a metric to alter the behavior of the metrics.
Expression - based
transformations – You implement these transformations
using a mathematical formula
in Microstrategy Architect.
Table - based
transformations – These
transformations are based on a transformation – or relate –table in the
warehouse.
What is dynamic
Aggregation?
Rollup metric values that occurs when
an attribute is moved from the report grid to the report objects.
For Eg: The report grid has Quarter
and Customer City, Revenue. If we remove Quarter into the report objects then
revenue should automatically roll up to Customer City.
How to ensure that
a particular fact table will be chosen for a metric
The MSTR operates in such a way that
the incoming queries and data retrievals are done from the table which has the
least logical size. Thus if we prefer a specific table to be the center of
activity then we should try to reduce the logical size of that specific table
so that it becomes considerably lesser than the other tables.
In Microstrategy,
how can you direct the sql generated to use a specifc table?
Using the Level parameter in the Metric level options
Assuming you have OLAP licence,the easiest way to direct to a particular table is to create a dummy fact on the table,include the fact in metric and put the metric in report objects.
How to hide a
particular metric in a report for a specific user?
Using Object level security
What is Metric
Formula Join Type? How it is different with Metric Join Type?
Metric Formula Join Type is used for
Compound Metrics and determines how the different tables used in metric formula
are joined.
Whereas the Metric Join Type
determines how the metrics are joined to other metrics.
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