IBM PureData System for Analytics, Version 7.1

The nzsession command

Use the nzsession command to view and manage sessions.

Syntax

The nzsession command uses the following syntax:

nzsession subcmd [subcmd options]

Inputs

The nzsession command takes the following inputs:

Table 1. The nzsession input options
Input	Description
nzsession abort `options`	Abort a running user session.
nzsession abortTxn `options`	Abort a user transaction.
nzsession listSessionTypes	Lists the session types, which include the following types: sql = database SQL session sql-odbc = database SQL session through ODBC sql-jdbc = database SQL session through JDBC load = data load session (nzload) client = client UI or CLI session bnr = Backup and restore session reclaim = database reclaim session (nzreclaim) loadsvr = data load session (deprecated loader)
nzsession priority `options`	Changes priority of the current and all subsequent jobs of this session.
nzsession show `options`	Displays the list of current user sessions.

Options

The nzsession command takes the following options:

Table 2. The nzsession options
Command	Option	Description
All nzsession commands	-u `user`	Specifies the database user name [NZ_USER].
	-pw `password`	Specifies the user password [NZ_PASSWORD].
	-host `name`	Specifies host name or IP address [NZ_HOST]. Except listSessionTypes.
	-caCertFile `path`	Specifies the path name of the root CA certificate file on the client system. This argument is used by IBM® Netezza® clients who use peer authentication to verify the Netezza host system. The default value is NULL, which skips the peer authentication process.
	-securityLevel `level`	Specifies the security level that you want to use for the session. The argument has four values: preferredUnSecured This value is the default value. Specify this option when you would prefer an unsecured connection, but you accept a secured connection if the Netezza system requires one. preferredSecured Specify this option when you want a secured connection to the Netezza system, but you accept an unsecured connection if the Netezza system is configured to use only unsecured connections. onlyUnSecured Specify this option when you want an unsecured connection to the Netezza system. If the Netezza system requires a secured connection, the connection is rejected. onlySecured Specify this option when you want a secured connection to the Netezza system. If the Netezza system accepts only unsecured connections, or if you are attempting to connect to a Netezza system that is running a release before 4.5, the connection is rejected.
	-timeout `secs`	Specifies the time to wait in seconds for the command to complete. The default is 300.
nzsession abort, and abortTxn	-id `num`	Specifies the session ID.
nzsession abort, and abortTxn	-force	Does not prompt for confirmation.
nzsession priority	-id `num`	Specifies the session ID.
	-high	Changes the session priority to high.
	-normal	Changes the session priority to normal.
	-low	Changes the session priority to low.
	-critical	Changes the session priority to critical.
nzsession show	-activeTxn	Displays the active transactions for the system.
nzsession show	-maxColW `chars`	Specifies the maximum number of characters to print in a column. The default is 24.

Description

The nzsession command does the following:

Privileges required: The admin user has full privileges to display all session information, to abort sessions and transactions, and to change the priority of a session. Other database user accounts require no special privileges to use the nzsession show command to see all the sessions that are currently active on the system. However, non-admin users see asterisks instead of the user name, client process Id (PID), database, and SQL command unless they have List privilege on User (to see details about the user, client PID, and SQL command) and List privilege on Database (to see the database name). Users must have the Manage System privilege to change the priority of sessions, and Abort privilege to abort sessions, transactions, or both.
Common tasks: Use the nzsession command to manage sessions. You cannot use a Release 5.0 nzsession client command to manage sessions on a Netezza system that is running a release before 5.0.

How the command handles abort processing

When you run the nzsession abort command, the client manager uses the session ID to abort the process.

For example, to abort an nzload session ID 2001, the system does the following:

The system sends the nzsession abort command to the client manager.
The client manager identifies which nzload session to abort.
The loadmgr sends the abort signal to the loadsvr and starts the timer.
The loadmgr waits the specified timeout value for the loadsvr to abort the session. The command uses either the default value, or the timeout you specify on the command line.

You can also abort active or idle nzsql sessions.

The nzsession show output

The following table describes the nzsession show output information. The admin user can see all the data for sessions; other users can see all the sessions, but data for user, database, client PID, and SQL command are hidden unless the user has privileges to see that data.

Table 3. Session information
Column	Description
ID	The ID of the session.
Type	The type of session, which can be one of the following: Client Client or UI session SQL Database SQL session Bnr Back up or restore session Reclaim Disk reclamation session.
User	The name of the session owner.
Start Time	The time the session was started.
PID	The process identification number of the command you are running.
Database	The name of the database.
Schema	The name of the schema.
State	The state of the session, which can be one of the following: Idle The session is connected but it is idle and waiting for a SQL command to be entered. Active The session is running a command (usually applies to a SQL session that is running a query). Connect The session is connected, but no commands have been issued. Tx-Idle The session is inside an open transaction block (BEGIN command) but it is idle and waiting for a SQL command to be entered within the transaction.
Priority Name	The priority of the session, which can be one of the following: Critical The highest priority for user jobs. High The session jobs are running on the high priority job queue. Normal The session jobs are running on the large or small job queue. Low The lowest priority for user jobs.
Client IP	The IP address of the client system.
Client PID	The process identification number of the client system.
Command	The last command executed.

Usage

The following provides sample usage:

To show all sessions, enter:

nzsession show -u bob -pw password 
ID    Type User  Start Time               PID  Database  Schema State Priority
Client IP Client Command
                                                                      Name
          PID
----- ---- ----- ----------------------- ----- --------- ------ ------ --------
--------- ------ ------------------------
16049 sql  ***** 24-Feb-13, 16:49:18 EST 14840 *****     ADMIN active normal
***** *****  *****
16054 sql  bob   24-Feb-13, 16:49:31 EST 15093 SYSTEM    ADMIN active normal
127.0.0.1 15092 SELECT session_id, clien

This sample output displays for a user (bob) who does not have permission to see the details of the sessions on the system. Only the details for the sessions for the user bob display. For a user who has List permission on user and database objects, the output shows all the details:

nzsession show -u sysadm -pw password
ID    Type User   Start Time               PID  Database  Schema State Priority
Client IP Client Command
                                                                      Name
          PID
----- ---- -----  ----------------------- ----- --------- ------ ------ --------
--------- ------ ------------------------
16049 sql  DBUSR  24-Feb-13, 16:49:18 EST 14840 TPCH1     ADMIN active normal
127.0.0.1 14839 select * from lineitem
16054 sql  bob    24-Feb-13, 16:49:31 EST 15093 SYSTEM    ADMIN active normal
127.0.0.1 15092 SELECT session_id, clien

To abort a session, enter:

nzsession abort -u user -pw password -host nzhost -id 1344

To abort a transaction, enter

nzsession abortTxn -u user -pw password -host nzhost -id 437

To list the types of sessions, enter:
```
nzsession listSessionTypes
```

To change the session priority, enter:

nzsession priority -u user -pw password -host nzhost -id 437 -high

To show all the active transactions, enter:
```
nzsession show -activeTxn 
```
You can use the -activeTxn option to display the active sessions that will be impacted by a state change (such as pausing -now) before you initiate the state change.