Nonstop Database, HiRDB Version 9 System Definition

[Contents][Index][Back][Next]

2.2.29 Operands related to referential and check constraints

157) pd_constraint_name = LEADING | TRAILING
Specifies whether to specify a constraint name definition before or after constraint definition in referential constraint or check constraint.
LEADING:
Specifies a constraint name definition before constraint definition (standard SQL specification).
TRAILING:
Specifies a constraint name definition after constraint definition (XDM/RD-compatible specification).

158) pd_check_pending = USE | NOUSE
Specifies whether the check pending status (state that prevents the use of data for which integrity can no longer be guaranteed) is to be used in referential constraint or check constraint.
USE: Use the check pending state.
NOUSE: Do not use the check pending state.
Specification guidelines
Normally specify USE. If NOUSE is specified in this operand, data integrity might not be guaranteed. If processing performance is more important then data integrity, or if neither referential constraint nor check constraint are used, specify NOUSE.
Notes
If USE is specified in this operand or the operand is omitted, HiRDB does the following when it executes the PURGE TABLE statement:
  • Temporarily locks the data dictionary table (resource type: 3005, type name: DICT) by placing it in EX mode.
  • Locks the data dictionary RDAREA (resource type: 0001, type name: RDAR) by placing it in SU mode until the transaction is terminated.
Therefore, any other command or a utility that attempts to lock these resources might not be concurrently executable. If a command or a utility satisfies the conditions listed below, do not attempt to execute the command or utility concurrently.
Command or utility Condition
pdmod (database structure modification utility) The attribute definition of a data dictionary is changed.
pdcopy (database copy utility) The following two conditions are satisfied:
  • x or r is specified in the -M option.
  • The data to be copied includes a master directory RDAREA or a data dictionary RDAREA.
pdreginit (registry facility initialization utility) all is specified in the -k option.

[Contents][Back][Next]

[Trademarks]

All Rights Reserved. Copyright (C) 2014, Hitachi, Ltd.