ALTER LS POLICY Statement

Syntax

ALTER LS POLICY policy-name option-value-list [ WITH STOP SERVER ]

Parameters

option-value-list – { option-name = value } ...

option-name –

 
 ALLOW_COORDINATOR_AS_MEMBER = < ON | OFF >
| DQP_ENABLED = < 0 | 1 | 2 >
| LOGIN_REDIRECTION = < ON | OFF >
| REDIRECTION_WAITERS_THRESHOLD =  < num >
| TEMP_DATA_IN_SHARED_TEMP = < ON | OFF >

Applies to

Multiplex only.

Examples

Example 1 – alters the logical server policy:

ALTER LS POLICY root
ALLOW_COORDINATOR_AS_MEMBER=ON

Example 2 – alters the logical server policy and causes servers to shut down automatically when the option value changes:
```
ALTER LS POLICY root
TEMP_DATA_IN_SHARED_TEMP=ON WITH STOP SERVER
```

Usage

The option values listed are modified for the new policy. Any unspecified option inherits its value from the root logical server policy.

Logical Server Policy Options
Logical Server Policy Option	Allowed Values	Behavior
ALLOW_COORDINATOR_AS_MEMBER	ON, OFF	Can only be set for the ROOT logical server policy. When ON (the default), the coordinator can be a member of any user-defined logical server. OFF prevents the coordinator from being used as a member of any user-defined logical servers.
DQP_ENABLED	0, 1, 2	When set to 0, query processing is not distributed. When set to 1 (the default), query processing is distributed as long as a writable shared temporary file exists. When set to 2, query processing is distributed over the network, and the shared temporary store is not used.
LOGIN_REDIRECTION	ON, OFF	When ON, enables login redirection for logical servers governed by specified login policy. When OFF (the default), disables login redirection at the logical server level, allowing external connection management.
REDIRECTION_WAITERS_THRESHOLD	Integer	Specifies how many connections can queue before SAP Sybase IQ redirects a connection to this logical server to another server. Can be any integer value; default is 5.
TEMP_DATA_IN_SHARED_TEMP	ON, OFF	When ON, all temporary table data and eligible scratch data writes to the shared temporary store, provided that the shared temporary store has at least one read-write file added. You must restart all multiplex nodes after setting this option or after adding a read-write file to the shared temporary store. (If the shared temporary store contains no read-write file, or if you do not restart nodes, data is written to IQ_SYSTEM_TEMP instead.) When OFF (the default), all temporary table data and scratch data writes to the local temporary store.

If you want a smaller IQ_SYSTEM_TEMP dbspace, turn TEMP_DATA_IN_SHARED_TEMP ON, which writes temporary data to IQ_SHARED_TEMP instead of IQ_SYSTEM_TEMP. In a distributed query processing environment, however, setting both DQP_ENABLED and TEMP_DATA_IN_SHARED_TEMP ON may saturate your SAN with additional data in IQ_SHARED_TEMP, where additional I/O operations against IQ_SHARED_TEMP may adversely affect DQP performance.

WITH STOP SERVER automatically shuts down all servers in the logical server when the TEMP_DATA_IN_SHARED_TEMP option is changed directly or indirectly.

This statement enforces consistent shared system temporary store settings across physical nodes shared by logical servers.

Permissions

Requires the MANAGE MULTIPLEX system privilege.