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.
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.
Filters
What is filter?
Filter is used to
restrict data in a report
What is report as filter?
In the
MicroStrategy when the same filter conditions must be applied to multiple
passes, the same where clause appears in each of those passes. This redundant
where clause can be expensive if the filter conditions are complicated and thus
involve many tables and joins. Ideally, an intermediate table populated with
entries could be created to satisfy the complicated filter conditions so that
the rest of the SQL statements can use that intermediate table. In that case,
the where clause would be executed only once instead of multiple times and SQL
performance would be improved. In this case to populate the temporary table we
can use report as a filter
What is view filter?
View Filters: View Filters are the conditions
that come into play before a specific result is presented to the user. Thus the
view filters are not part of the SQL statements like report definitions, rather
they are the filters applied after the execution of the SQL statements, after
the data is retrieved from the data warehouse.
What is filtered prompt?
We can restrict the
number of elements in a prompt using a filter.
Difference between report and view filter?
Report filters: report filters are the conditions
that accompany the report generating SQL statements. The report definitions
have the filters as part of their definition.
View Filters: View Filters are the conditions
that come into play before a specific result is presented to the user. Thus the
view filters are not part of the SQL statements like report definitions, rather
they are the filters applied after the execution of the SQL statements, after
the data is retrieved from the data warehouse.
Difference between Report Limit and Report filter?
A report limit
specifies a set of criteria used to restrict the data returned in the report
data set after the report metrics are calculated.
Report Filter
applies the where condition to the query sent to warehouse to extract the
results.
What is the difference between Absolute filtering and standard
filtering?
When we use the
absolute filtering in definition of level metric whatever data we obtain
from the filter is goingto be reported as such and the the report filter will
be overridden by the absolute filter settings. The standard filtering the
report filter interacts with the metric filter in the normal way and what we
obtain will be formatted according to the report filter settings.
What is a Joint Element List Filter?
Helps
to choose combination of attribute elements from different attributes to filter
a report
Enables to create filters with attribute pairs
as well as triplets, quadruplets and so on.
This is available in the advanced qualification
section of the filters
What is a Security filter?
Security filter is
used to apply security at the database data level.Whenevera users associated
with security filter runs a report, a WHERE clause is always included in the
report sql with the condition defined in the Security Filter.
What is a Attribute to Attribute Filtering?
This is used to
compare values of 2 attributes using their forms.
Eg: Ship
Date<Day(ID)+2
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