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

Introduction
HP NonStop SQL/MX Reference Manual—540440-003
1-17
Concurrency
Table 1-3 compares DML operations you can start when DDL operations are in
progress:
REVOKE Allowed
*
Allowed Waits Waits
UPDATE STATISTICS Allowed Allowed Allowed Allowed
**
* DDL operation aborts the DML operation
** Allowed except during commit phase
*** There are some exceptions. Dropping a partition from a hash partitioned table or index requires exclusive
access.
Table 1-3. Concurrent DML and DDL Operations
DML Operations You Can Start
DDL Operations in Progress
SELECT
UNCOMMITTED
SELECT
SHARE
SELECT
EXCLUSIVE
UPDATE/
INSERT
DELETE
ALTER INDEX Allowed
*
Allowed Allowed Allowed
ALTER TABLE attributes Allowed
*
Allowed Allowed Allowed
ALTER TABLE other Allowed
*
Waits Waits Waits
CREATE INDEX with
POPULATE
Allowed
*
Allowed Waits Waits
CREATE INDEX NO
POPULATE
Allowed Allowed Allowed Allowed
CREATE TRIGGER subject
table
Allowed Allowed Waits Waits
CREATE TRIGGER
referenced table
Allowed Allowed Allowed Allowed
CREATE VIEW Allowed Allowed Allowed Allowed
GRANT Allowed
*
Waits Waits Waits
MODIFY online operations Allowed
*
Allowed Waits Waits
MODIFY offline operations
***
Allowed
*
Allowed
**
Allowed
**
Waits
POPULATE INDEX Allowed
*
Allowed
**
Allowed
**
Waits
REVOKE Allowed
*
Allowed Waits Waits
UPDATE STATISTICS Allowed Allowed Allowed Allowed
**
* DDL operation aborts the DML operation
** Allowed except during commit phase
*** There are some exceptions. Dropping a partition from a hash partitioned table or index requires exclusive
access.
Table 1-2. Concurrent DDL/Utility and DML Operations
DML Operation in Progress
DDL Operations You Can
Start
SELECT
UNCOMMITTED
SELECT
SHARE
SELECT
EXCLUSIVE
UPDATE/
INSERT/
DELETE