7.127 V$CIRCUIT

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:

  • BREAK - currently interrupted

  • EOF - about to be removed

  • OUTBOUND - an outward link to a remote database

  • NORMAL - normal circuit into the local database

QUEUE

VARCHAR2(16)

Queue the circuit is currently on:

  • COMMON - on the common queue, waiting to be picked up by a server process

  • DISPATCHER - waiting for the dispatcher

  • SERVER - currently being serviced

  • NONE - idle circuit

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

BOUND_TIMEFoot 1

NUMBER

Time that a circuit and shared server have been bound (in centiseconds)

BOUND_REASONFoot 1

VARCHAR2(32)

Provides a reason (a short explanation) for why a shared server and circuit could not be unbound.

This column is empty when a circuit is not bound to a server.

When the server starts serving a circuit, BOUND_REASON is empty and remains empty unless the server tries unsuccessfully to unbind the circuit (after it finishes serving the current request).

When this column is not empty, it will be cleared once the server and circuit are unbound (that is, once the resources preventing the session migration to another shared server are released).

CON_ID

NUMBER

The ID of the container to which the data pertains. Possible values include:

  • 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.

  • 1: This value is used for rows containing data that pertain to only the root

  • n: Where n is the applicable container ID for the rows containing data

Footnote 1 This column is available starting with Oracle Database release 19c, version 19.1.