V$CIRCUIT contains information about virtual circuits, which are user connections to the database through dispatchers and servers.
| Column | Datatype | Description | 
|---|---|---|
| CIRCUIT | RAW(4 | 8) | Circuit address | 
| DISPATCHER | RAW(4 | 8) | Current dispatcher process address | 
| SERVER | RAW(4 | 8) | Current server process address | 
| WAITER | RAW(4 | 8) | Address of the server process that is waiting for the (currently busy) circuit to become available | 
| SADDR | RAW(4 | 8) | Address of the session bound to the circuit | 
| STATUS | VARCHAR2(16) | Status of the circuit: 
 | 
| QUEUE | VARCHAR2(16) | Queue the circuit is currently on: 
 | 
| MESSAGE0 | NUMBER | Size in bytes of the messages in the first message buffer | 
| MESSAGE1 | NUMBER | Size in bytes of the messages in the second message buffer | 
| MESSAGE2 | NUMBER | Size in bytes of the messages in the third message buffer | 
| MESSAGE3 | NUMBER | Size in bytes of the messages in the fourth message buffer | 
| MESSAGES | NUMBER | Total number of messages that have gone through this circuit | 
| BYTES | NUMBER | Total number of bytes that have gone through this circuit | 
| BREAKS | NUMBER | Total number of breaks (interruptions) for this circuit | 
| PRESENTATION | VARCHAR2(257) | Presentation protocol used by the client and server | 
| PCIRCUIT | RAW(4 | 8) | Address of the parent circuit |