Rebuild index after deleting data for Sybase and Oracle

Hi, I'm doing a porting from sybase to Oracle. After deleting a bunch of data from a table, the original program use "update statistics" to update index in this table, then it call a store procedure named "sp_recompile", which appling to a table to rebuild all store procedure and trigger used this table.(for more infomation http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.help.ase_15.0.sprocs/html/sprocs/sprocs181.htm) Here is my question: In Oracle, after update index using "alter index indexname rebuild", do I need to something corresponding to the "sp_recompile" in sybase? If so, how to do it? somebody told me to use "execute DBMS_STATS.GATHER_DATABASE_STATS", is that correct?

no need to rebuild index, DBMS_STATS.GATHER_DATABASE_STATS maybe turn query faster in future. Suggest disabling index and trigger while deleting.