SQL/MX 2.x Installation and Management Guide (G06.24+, H06.03+)

Reviewing and Setting System Defaults
HP NonStop SQL/MX Installation and Management Guide—523723-004
6-2
Consequences of Inserting Rows Into the
SYSTEM_DEFAULTS Table
The statements in this example insert a default into the SYSTEM_DEFAULTS table on
\MYSYS to set the default setting for the transaction isolation level:
SET SCHEMA nonstop_sqlmx_mysys.system_defaults_schema;
INSERT INTO SYSTEM_DEFAULTS
(ATTRIBUTE, ATTR_VALUE)
VALUES ('ISOLATION_LEVEL', 'SERIALIZABLE');
The statements in this example update the current default setting for the transaction
isolation level on \MYSYS:
SET SCHEMA nonstop_sqlmx_mysys.system_defaults_schema;
UPDATE SYSTEM_DEFAULTS
SET ATTR_VALUE = 'READ COMMITTED'
WHERE ATTRIBUTE = 'ISOLATION_LEVEL';
Consequences of Inserting Rows Into the
SYSTEM_DEFAULTS Table
Changes you make through the SYSTEM_DEFAULTS table are permanent until
changed by a DELETE statement or another UPDATE statement. However, the values
you insert into the SYSTEM_DEFAULTS table do not affect your current session
immediately. You must exit and then reenter the MXCI session for these values to take
effect as system-level default settings. In addition, these insertions do not affect
previously compiled modules until you recompile them.
If an attribute has a value in the SYSTEM_DEFAULTS table and a CONTROL QUERY
DEFAULT statement, a CONTROL TABLE statement, or a SET TABLE statement is
issued for that attribute, the value specified by CONTROL QUERY DEFAULT takes
precedence over the value in the SYSTEM_DEFAULTS table for the current session.
For more information about system defaults and the SYSTEM_DEFAULTS metadata
table, see the SQL/MX Reference Manual.