What is the precise execution process of an SSRS report with Oracle query?

Hi all,

Just curious about some of the details about how the query embedded in an SSRS report actually GETS to the Oracle database.

In particular, is the oracle query ACTUALLY executed as some sort of t-sql wrapped openquery? or is the execution a more direct sort of thing, not having any mssql/tsql execution of the oracle query at all?

thanks,

sff