JOINS in SAP HANA
To address some specific business cases and have improved execution, SAP HANA introduces some additional JOINS on top of existing SQL JOINS. These SAP HANA specific JOINS are as follows:
- Referential JOIN
- Text JOIN
- Temporal JOIN
- Star JOIN
- Spatial JOIN
Let's see the scenarios when we should consider using these SAP HANA specific JOINS :
|
Type |
Scenario / use case |
Remarks |
|---|---|---|
|
Referential JOIN |
Facts with matching dimensions only where referential integrity is ensured. |
It's the default join type in SAP HANA. Facts returned are dependent on queried attributes. |
|
Text JOIN |
Multi language table. |
Needs a language column. Behaves as the left outer join. |
|
Temporal JOIN |
A key date within a validity period. |
Acts as a referential join. |
|
Star JOIN |
Star schema scenarios. |
Needs data organized in a star schema. All attributes and hierarchies are included. |
|
Spatial join |
Geospatial data. |
Only available in calculation views. |
