Monitors external sessions.

Monitors external sessions. Use this table to perform the following tasks:

  • Identify users who are running lengthy queries.

  • Identify users who hold locks because of an idle but uncommitted transaction.

  • Determine the details of the database security used for a particular session, either Secure Socket Layer (SSL) or client authentication.

  • Identify client-specific information, such as client version.

Column Name Data Type Description
NODE_NAME VARCHAR The node name for which information is listed.
USER_NAME VARCHAR The name used to log in to the database or NULL if the session is internal.
CLIENT_OS_HOSTNAME VARCHAR The hostname of the client as reported by their operating system.

The IP address and port of the TCP socket from which the client connection was made; NULL if the session is internal.

Vertica accepts either IPv4 or IPv6 connections from a client machine. If the client machine contains mappings for both IPv4 and IPv6, the server randomly chooses one IP address family to make a connection. This can cause the CLIENT_HOSTNAME column to display either IPv4 or IPv6 values, based on which address family the server chooses.

CLIENT_PID INTEGER The process identifier of the client process that issued this connection. Remember that the client process could be on a different machine than the server.
LOGIN_TIMESTAMP TIMESTAMP The date and time the user logged into the database or when the internal session was created. This field can help you identify sessions that have been left open for a period of time and could be idle.
SESSION_ID VARCHAR The identifier required to close or interrupt a session. This identifier is unique within the cluster at any point in time but can be reused when the session closes.
IDLE_SESSION_TIMEOUT VARCHAR Specifies how long this session can remain idle before timing out, set by SET SESSION IDLESESSIONTIMEOUT.
GRACE_PERIOD VARCHAR Specifies how long a session socket remains blocked while awaiting client input or output for a given query, set by SET SESSION GRACEPERIOD. If the socket is blocked for a continuous period that exceeds the grace period setting, the server shuts down the socket and throws a fatal error. The session is then terminated.
CLIENT_LABEL VARCHAR A user-specified label for the client connection that can be set when using ODBC. See Label in ODBC DSN connection properties. An MC output value means there are is a client connection to an MC-managed database for that USER_NAME
TRANSACTION_START DATE The date/time the current transaction started or NULL if no transaction is running.
TRANSACTION_ID INTEGER A string containing the hexadecimal representation of the transaction ID, if any; otherwise, NULL.
TRANSACTION _DESCRIPTION VARCHAR Description of the current transaction.
STATEMENT_START TIMESTAMP The timestamp the current statement started execution, or NULL if no statement is running.

A unique numeric ID assigned by the Vertica catalog, which identifies the currently-executing statement.

A value of NULL indicates that no statement is currently being processed.

LAST_STATEMENT_DURATION_US INTEGER The duration of the last completed statement in microseconds.
RUNTIME_PRIORITY VARCHAR Specifies how many run-time resources (CPU, I/O bandwidth) are allocated to queries that are running in the resource pool.
CURRENT_STATEMENT VARCHAR The currently executing statement, if any. NULL indicates that no statement is currently being processed.
LAST_STATEMENT VARCHAR NULL if the user has just logged in; otherwise the currently running statement or the most recently completed statement.

Indicates if Vertica used Secure Socket Layer (SSL) for a particular session. Possible values are:

  • None—Vertica did not use SSL.

  • Server—Server authentication was used, so the client could authenticate the server.

  • Mutual—Both the server and the client authenticated one another through mutual authentication.

See Security and authentication and TLS protocol.


The type of client authentication used for a particular session, if known. Possible values are:

  • Unknown

  • Trust

  • Reject

  • Hash

  • Ident

  • LDAP

  • GSS

  • TLS

See Security and authentication and Configuring client authentication.


The type of client from which the connection was made. Possible client type values:

  • ADO.NET Driver

  • ODBC Driver

  • JDBC Driver

  • vsql

CLIENT_OS VARCHAR Client operating system.
CLIENT_OS_USER _NAME VARCHAR The name of the user that logged into, or attempted to log into, the database. This is logged even when the login attempt is unsuccessful.
CLIENT_AUTHENTICATION_NAME VARCHAR User-assigned name of the authentication method.
CLIENT_ AUTHENTICATION INTEGER Object identifier of the client authentication method.
REQUESTED_PROTOCOL INTEGER The requested Vertica client server protocol to be used when connecting.
EFFECTIVE_PROTOCOL INTEGER The requested Vertica client server protocol used when connecting.
EXTERNAL_MEMORY_KB INTEGER Amount of memory consumed by the Java Virtual Machines associated with the session.


A superuser has unrestricted access to all session information. Users can view information only about their own, current sessions.

See also