Dan Todor wrote: > Thank you for your kind answer, I partially understood now. I > still have one > question : why the index on primary key is actually used ( or at least > that's my understanding of explain plan output), while a > regular index isn't > ? Or indexes aren't used in both cases ? NB, resultsets are > exactly same > size for both queries, so I assume same amount of data is analysed.
In SAP DB the primary key is no separate structure or index. The data in SAP DB is stored in B* trees and the primary key is the key in this tree. So the usage of any primary key range doesn't result in additional I/O. For more information about data structure have a look into http://www.sapdb.org/7.4/htmhelp/7e/90973b7889a326e10000000a114084/frameset.htm Best regards, Holger SAP Labs Berlin _______________________________________________ sapdb.general mailing list [EMAIL PROTECTED] http://listserv.sap.com/mailman/listinfo/sapdb.general
