I am a newbie to Oracle and I know that oracle uses two AWR snapshots to create an AWR report. What are three basic requirements that determine whether an AWR snapshot is usable? Or in other words a snapshot can be used for generating an AWR report.
I also have another question. Out of the AWR tables (not the DBA_HIST views) which is the main snapshot table. I want to know which is the most important AWR table for snapshots.
Any help will be greatly appreciated.