The FI-GL table BSEG, which is one of our biggest PR1 tables, is an example of a clustered table. At the database-level, there is no table called BSEG, but instead RFBLG is being used for the BSEG data. Most of the fields known in BSEG are not known in the database table RFBLG, but are compressed in a VARDATA field of RFBLG. So tests in the WHERE clause of SELECTs agains BSEG are not used by the database (e.g. lifnr = vendor account number, hkont = G/L account, kostl = cost center). As a consequence, these tests are done after the facts similar to using the CHECK statement, and as already said in tip 1, CHECK statements are worse than tests in the WHERE-clause.
Check this link also.
https://forums.sdn.sap.com/thread.jspa?forumID=50&threadID=38572&messageID=373481#373481
1) select with header information from bkpf
2) use secondary index tables
http://forums.sdn.sap.com/jive3/thread.jspa?forumID=50&threadID=14280&messageID=105504#105504
1.BSAK Accounting: Secondary Index for Vendors
2.BSAS Accounting: Secondary Index for G/L Accounts
3.BSIK Accounting: Secondary Index for Vendors
4.BSID Accounting: Secondary Index for Customers
5.BSIM Secondary Index, Documents for Material
6.BSAD Accounting: Secondary index for customers
7.BSIS Accounting: Secondary Index for G/L Accounts
3) use logical data base e.g.: BRF
