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

Introduction
HP NonStop SQL/MX Reference Manual—540440-003
1-20
Concurrency
Utilities that update
metadata and read
and potentially write
user data online:
MODIFY with
SHARED access
UPDATE STATISTICS
All DML operations are
allowed.
Utilities that read
metadata can
only be performed
concurrently.***
Not allowed.
* There are some exceptions. Dropping a partition from a hash partitioned table or index requires exclusive
access.
** The last phase of these operations requires exclusive access to the table or index, which prevents even
SELECT operations.
*** The last phase of the MODIFY operation requires exclusive access to the table or index, which prevents all
DDL and DML operations.
Utilities that update
data and potentially
change metadata:
FIXUP
DUP (target table only)
IMPORT using fast
load
MODIFY when
dropping a hash
partition
PURGEDATA
RESTORE
Not allowed. Concurrent
operations are not
allowed.
Not allowed.
* There are some exceptions. Dropping a partition from a hash partitioned table or index requires exclusive
access.
** The last phase of these operations requires exclusive access to the table or index, which prevents even
SELECT operations.
*** The last phase of the MODIFY operation requires exclusive access to the table or index, which prevents all
DDL and DML operations.
Table 1-5. Concurrency Limits on Utility Operations (page 2 of 2)
Utility DML operations Other utilities
DDL
operations