Describe the Oracle Wait Interface

The Oracle Wait Interface refers to Oracle's data dictionary for managing wait events. Selecting from tables such as v$system_event and v$session_event give you event totals through the life of the database (or session). The former are totals for the whole system, and latter on a per session basis. The event db_file_sequential_read refers to single block reads, and table accesses by rowid. db_file_scattered_read conversely refers to full table scans. It is so named because the blocks are read, and scattered into the buffer cache.