SID Generation check while creating DSO

Hi

I have new learnt SAP BI BW and started working on it. Thus I have one query regarding to Standard DSO. There is a check box for SID Generation under Setting.

1. What is the practical use of this. However I have found some useful docs regarding this. in docs, it was mentioned that SIDs are created for master data during activation (If this is checked) or reporting (If this is checked). If the SID is not available, then SAP BW creates SID for them. It is therefore used for Query.
2. What is the advantage of selecting this option or disadvantages of not selecting it.
3. How it impact it queries (if I select it or If I don't select it)

Thanks, you input will be highly appreciated.

Regards,

David