• Application: locks waits caused by row level locking or explicit lock commands
• Commit: waits for redo log write confirmation after a commit
• Idle: wait events that signify the session is inactive, such as SQL*Net message from client
• Network: waits for data to be sent over the network
• User I/O: wait for blocks to be read off a disk
The V$SYSTEM_EVENT view shows wait event statistics for the foreground activities of a database instance and the wait event statistics for the database instance.
