User and group limits

You can place limits on the resources that users and groups can use. You can limit the number of rows that a query can return (rowset limit), the amount of time a session can remain idle before it is terminated (session timeout), the amount of time a query can run before the system notifies you, the session priority, and the number of days before the account password expires.

The IBM Netezza Appliance and IBM Netezza Appliance system calculates the limit for each user based on the following rules:

If the attribute is set for the user account, use that value.
If the attribute is not set for the USER, use the MOST RESTRICTIVE value set for any of the groups of which that user is a member.
If the attribute is not set for the user or any of the user’s groups, use the system default value.

The following table describes these settings.

Table 1. User and group settings
Setting	Scope	Valid range	Default value	Description
Rowset limit	User, group, and system	1 - 2,147,483,647 or unlimited (zero)	Unlimited (zero)	Maximum rowset limit per query. For more information, see User rowset limits.
Query timeout	User, group, and system	1 - 2,147,483,647 minutes or unlimited (zero)	Unlimited (zero)	Maximum time that is allocated to a query. For more information, see Query timeout limits.
Session limit	User, group, and system	1 - 2,147,483,647 minutes or unlimited (zero)	Unlimited (zero)	When a SQL session is idle for longer than the specified period, the system terminates the session. For more information, see Session timeout.
Session priority	User, group, and system	Critical, high, normal, or low	None	Defines the default and maximum priority for the user or group.
Password expiration	User, group, and system	0 or any positive int value	0 (password does not expire)	Defines how many days that the password for the account is valid. Used only for local authentication accounts. For more information, see Password expiration.

When you change these values, the system sets them at session startup and they remain in effect for the duration of the session.

You specify the system defaults with the SET SYSTEM DEFAULT command. To display the system values, use the SHOW SYSTEM DEFAULT command.

To set a system default, use a command similar to the following, which sets the default session timeout to 300 minutes:
```
SYSTEM.ADMIN(ADMIN)=> SET SYSTEM DEFAULT SESSIONTIMEOUT TO 300;
SET VARIABLE
```

To show the system default for the session timeout, use the following syntax:

   SYSTEM.ADMIN(ADMIN)=> SHOW SYSTEM DEFAULT sessiontimeout;
NOTICE:  'session timeout' = '300'
SHOW VARIABLE