Performance issue-Inconsistent

12.1.0.2 ,RHEL 6  -Turned off adaptive features

Hello Gurus,

One of our application is driving us nuts with the frequent plan changes ,i know we could provide plan stability with SPM .My client doesn't want to listen anymore about plan changing be the reason for the slowness. How can i make sure it doesn't happend and what could be the reason for it, should i lock statistics?

Can't seem to find any reason for it in v$sql_shared_cursor most of the time find no rows for the sql_id ,Why doesn't  v$sql_shared_cursor has an entry for some of the SQL's . Does SQL's need to have all bind variables or even mix of bind vriables and literals in the predicate where clauses should have an entry.