The below image shows the different engines available in HANA Database to process models execution. They are,
- Join Engine
- OLAP Engine
- Calculation Engine
- ROW Engine
- SQL Engines
1)JOIN Engine:
This engine is used when we execute any Attribute View in HANA or run native SQL on more than one table with join condition
If there are any calculations involved either in Attribute View or in native SQL then Join Engine will use Calculation Engine for calculations and fetches the result.
2)OLAP Engine:
This engine will be called in the backend whenever we run any queries on Analytic Views in SAP HANA.
If there are no additional calculations performed like calculated columns, restricted measures and counters, then everything will be processed in OLAP Engine.
OLAP Engine acts as join engine for those Attribute Views used in Analytic Views, without any calculated columns
All the join engine work will be converted into ‘BwPopJoin’ which is part of OLAP Engine.
If there are any calculations present, to be performed then Calculation engine will be used along with OLAP Engine.
3) CALCULATION Engine:
This engine is used to process complex calculation that cannot be processed by JOIN and OLAP Engine.
