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.
Note: During session initialization and termination, you might see sessions running only on nodes other than the node on which you ran the virtual table query. This is a temporary situation that corrects itself when session initialization and termination complete.
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_HOSTNAME
|
VARCHAR
|
The host name 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 |
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. |
STATEMENT_ID
|
INTEGER
|
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. |
|
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. |
SSL_STATE
|
VARCHAR
|
Indicates if Vertica used Secure Socket Layer (SSL) for a particular session. Possible values are:
See Security and Authentication and TLS/SSL Server Authentication. |
AUTHENTICATION_
METHOD
|
VARCHAR
|
The type of client authentication used for a particular session, if known. Possible values are:
See Security and Authentication and Implementing Client Authentication. |
CLIENT_TYPE
|
VARCHAR
|
The type of client from which the connection was made. Possible client type values:
|
CLIENT_VERSION
|
VARCHAR
|
Client version. |
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 protocol to be used when connecting. |
EFFECTIVE_PROTOCOL
|
INTEGER
|
The protocol used when connecting. |
EXTERNAL_MEMORY_KB
|
INTEGER
|
Amount of memory consumed by the Java Virtual Machines associated with the session. |
Privileges
A superuser has unrestricted access to all session information. Users can view information only about their own, current sessions.