Settings for Outer Join between metrics in MicroStrategy
MicroStrategy adopts multi-pass logic to determine the execution plan for a report. This means that every metric is evaluated in separate SQL passes.
Outer Joins come into play when MicroStrategy Engine merges the results from all SQL passes into one report. For a multi-pass report, different Outer Join behaviors can give the user completely different results.
In addition, report metrics can be of different types which can, in some cases, influence the result of the outer join.
In MicroStrategy, there are two settings that users can access to control Outer Join behavior: Formula Join Type and Metric Join Type.
Metric Join Type:
- VLDB Setting at Database Instance Level
- Report and Template Levels
- Report Editor > Data > Report Data Options
- Metric Level
- Metric editor > Tools > Metric Join Type
- Control Join between Metrics
Formula Join Type:
Only at Compound/Split Metrics Level
- Metric editor > Tools > Advanced > Formula Join Type
- Control Join between Component Metrics Inside Compound Metrics and Split Metrics
- Currently, metric join type for compound/split metrics can override formula join type.
C- Metrics Join Type Hierarchy
The following schema shows which setting takes precedence when set at different levels.
For example, setting Metric Join type to "Outer" at the report level (Metric editor > Tool > Metric Join Type) overwrites the Metric Join Type set at the Database Instance Level:
The subject of Outer Joins is a very broad one, however, as a continuation of the topics covered in this article, users might find it useful to refer to the following MicroStrategy Knowledge Base document:
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