SQL/MX 2.x Reference Manual (H06.04+)

Metadata Tables

HP NonStop SQL/MX Reference Manual—540440-003

10-69

Examples of SYSTEM_DEFAULTS Table

•

Insert a row into the SYSTEM_DEFAULTS table to set the current default setting

for the transaction isolation level:

INSERT INTO SYSTEM_DEFAULTS

(ATTRIBUTE, ATTR_VALUE)

VALUES ('ISOLATION_LEVEL', 'SERIALIZABLE');

•

Query the SYSTEM_DEFAULTS table to obtain the current default setting for the

transaction isolation level:

SELECT ATTRIBUTE, ATTR_VALUE FROM SYSTEM_DEFAULTS

WHERE ATTRIBUTE = 'ISOLATION_LEVEL';

•

Set a new value for the transaction isolation level:

UPDATE SYSTEM_DEFAULTS

SET ATTR_VALUE = 'READ COMMITTED'

WHERE ATTRIBUTE = 'ISOLATION_LEVEL';

•

Set the level of optimization for the next query to be executed. The CONTROL

QUERY DEFAULT statement does not change the settings of the

SYSTEM_DEFAULTS table.

CONTROL QUERY DEFAULT OPTIMIZATION_LEVEL '0';

Control query default

TEMPORARY_TABLE_HASH_PARTITIONS

'$data01,$data02:$data03';

If you specify more than one volume, the temporary table is

hash partitioned over all those partitions. Range partitioning is

not supported.

If no system default is specified, NonStop SQL/MX uses the

default location of the creator of the first trigger. If the default is

changed, the change affects temporary tables created after the

change. Previously created temporary tables will retain the

previous setting. The partitioning scheme of the trigger subject

table is unrelated to the temporary table.