What is the difference between a column view and external SAP HANA view?

[former_member612336]

Hello experts,

We have BW on HANA 7.5 system. We use column views (0BW:BIA:xxx:) generated from DSO in HANA studio in some case for reporting by creating projection nodes and semantics. We also use external SAP HANA view (generated from DSO or ADSO) which results in analytic view or calculation view in HANA studio, and also use them for reporting.

My question is, what is the difference between using these column views vs. using these external SAP HANA views? Why did SAP give a separate setting in DSO or ADSO to generate these external SAP HANA views? Can we not use the column views itself for reporting creating projections, etc. in HANA studio? Why did SAP have to give a separate setting to use these external HANA views? Is there any advantage of using these external SAP HANA views vs. using column views for reporting?

[former_member302041]

Hi,

Column views (0BW:BIA...) are SAP internal artifacts and not, so-called, "public interface".

Although we see them and can use them it is not supported by SAP - see note 2317197 Q22.

You may want to use generated external HANA views only (no column views, no active tables of DSO etc. - although we can use it and it is not blocked)

[john_hawk · Accepted solution]

Hi Ajay,

I'm going to give you short answers with enough keys words to research on your own.

1) At column view is based on a column store (based table as its central fact table. This is contrasted with a row store table. Research column store and row store tables in SAP HANA.

2) The External view switch creates a view which expose the table to external products. The views also make connections to master data attributes and text which would not be provided by a direct connection to the table. If the underlying DSO is a column store HANA table, the external view will also be a column view.

3) Research analytic vs calculation views. Calculation views may include functions optimized for execution on the HANA data base. Analytic views are simpler, used for simple "slice and dice" analysis.

4) SAP wanted to make BW InfoProviders more easily accessible to 3rd party BI tools and BusinessObjects. This the reason for the external view switch.

5) Yes, you may always create your own column views based on the underlying tables. Be careful getting the joins right. External views provide many of the joins for you.

John Hawk