The RDAREA opening trigger attribute refers to the time at which RDAREA open processing is executed by HiRDB.

Normally, RDAREA open processing is executed during HiRDB startup. However, as the number of RDAREAs increases, the amount of time required for HiRDB startup processing also increases. Instead, RDAREAs can be opened when they are accessed, rather than being opened during HiRDB startup processing. Thus, the RDAREA opening trigger attribute is changed. There are three trigger attributes for opening an RDAREA, as the following table shows.

Table 15-2 RDAREA opening trigger attributes

Trigger	Initial status	Opening time	Closing time	Advantages	Disadvantages
INITIAL	Open	During HiRDB startup During pdopen command execution	During pdclose command execution	High-speed execution from the first SQL	More time is required to start the system.
DEFER	Closed	First time RDAREA is accessed During pdopen command execution	During pdclose command execution	High-speed system startup High-speed processing of SQLs after the first access	More time is required to access the RDAREA for the first time.
SCHEDULE	Closed	First time RDAREA is accessed within a transaction During pdopen command execution	During transaction termination During pdclose command execution	High-speed system startup Fewer open files (for DVD-RAM library devices)	More time is required to access the RDAREA for the first time by each transaction.

Initially, the RDAREA opening trigger is INITIAL. We recommend you consider changing the RDAREA opening trigger in the following cases:

• HiRDB startup processing takes a long time because there is a large number of RDAREAs.
• A DVD-RAM library device is being used.

The following table shows the operating procedure appropriate to each trigger.

Table 15-3 Operating procedure appropriate to each trigger

Trigger	Appropriate operating procedure
INITIAL	HiRDB file system area is opened and the RDAREA information is made resident in memory during system startup. HiRDB file system area is also opened on the server process during the initial RDAREA access. In this case, the RDAREA information is not re-created; therefore, high-speed operation can be achieved from the first SQL. The initial status of RDAREAs is to be opened during system startup. This status does not change unless an operation command is entered, except for a status change to error shutdown. This trigger should be used when no special operating procedure is employed. When this trigger is used, a closed RDAREA cannot be accessed.
DEFER	HiRDB file system area is opened and the RDAREA information is made resident in memory when an RDAREA is accessed for the first time, not during system start. High-speed operation can be achieved for the subsequent accesses, because no processing is required on the HiRDB file system area other than open processing. The RDAREAs' initial status during system startup is closed. Each RDAREA is opened when it is accessed for the first time. The status of RDAREAs does not change thereafter unless an operation command is entered, except for a status change to error shutdown. Specify this attribute when you wish to avoid situations in which many HiRDB file system areas are open concurrently or you wish to reduce the time required for HiRDB startup. When HiRDB is restarted, any RDAREAs to be recovered are opened during recovery processing. When this trigger is used, a closed RDAREA can be accessed.
SCHEDULE	HiRDB file system area is opened and the RDAREA information is made resident in memory when an RDAREA is accessed for the first time within a transaction, without opening it during system startup. The HiRDB file system area is closed when the transaction terminates. The transaction processing workload increases because the open processing and all subsequent processing is executed the first time an RDAREA is accessed by each transaction. The RDAREAs' initial status during system startup is closed. An RDAREA is open only while a transaction that accesses it is being processed. When the transaction terminates, all the RDAREAs opened by it are closed. When the pdopen command is entered, an RDAREA can be kept in open status until it is placed in shutdown and closed status. Other operation commands can also be used to change the RDAREA status. When an error is detected, the RDAREA is placed in error shutdown status. Specify this attribute when you wish to avoid situations in which many HiRDB file system areas are open concurrently or you wish to reduce the time required for HiRDB startup when a DVD-RAM library device is being used. When HiRDB is restarted, any RDAREAs to be recovered are opened during recovery processing, and they are closed when recovery processing finishes. When this trigger is used, a closed RDAREA can be accessed.

The opening trigger attribute can be changed for the following RDAREAs:

• User RDAREAs
• User LOB RDAREAs
• List RDAREAs

1. Before an RDAREA's opening trigger attribute is changed, it must be placed in shutdown and closed status with the pdhold -c command.
2. Before an RDAREA whose opening trigger attribute has been changed can be used, it must be released from shutdown status and placed in open status by the pdrels -o command.
3. The same opening trigger attribute should be set for all RDAREAs in a HiRDB file system area.
4. RDAREAs are not open while the standby system unit to which the rapid system switchover facility switches is in standby status. In addition, because the purpose of this facility is to minimize system switchover time, only those RDAREAs that are needed for recovery when a system is switched over are opened, while the other RDAREAs remain closed. Therefore, the RDAREA opening trigger on a standby system is not the INITIAL attribute. RDAREAs set with the INITIAL attribute are changed to the DEFER attribute.
5. Because the purpose of the standbyless system switchover facility is to minimize system switchover time, this facility opens only those RDAREAs that are needed for recovery when a system is switched over, while the other RDAREAs remain closed. Therefore, the opening trigger of the RDAREAs on the alternate BES or the alternate portion is as follows:
   When system switchover occurs, the opening trigger for RDAREAs in the alternate portion is the SCHEDULE attribute.
   When returning the system to the normal BES after having recovered from the error, the opening trigger for RDAREAs set with the INITIAL or DEFER attribute is the DEFER attribute. The opening trigger for RDAREAs set with the SCHEDULE attribute remains unchanged.
   
6. The following table indicates the accessibility of UAP RDAREAs according to the open attribute.
   

   Table 15-4 Accessibility of UAP RDAREAs according to the open attribute

   Opening trigger for RDAREA	Status of RDAREA		RDAREA accessible?
   INITIAL	Not shutdown	Open	Yes
   		Closed	No
   	Command shutdown	Open	No
   		Closed	No
   	Reference-possible hold	Open	Some#2
   		Closed	No
   	Reference-possible backup hold#1	Open	Some#2
   	Updatable backup hold#1	Open	Yes
   	Error shutdown	Open	No
   		Closed	No
   	No-log hold	Open	Some#3
   		Closed	No
   	Initialization hold#1	Open	No#4
   		Closed	No#4
   	Online reorganization hold#1	Open	Some#5
   		Closed	Some#5
   DEFER or SCHEDULE	Not shutdown	Open	Yes
   		Closed	Yes
   	Command shutdown	Open	No
   		Closed	No
   	Reference-possible hold	Open	Some#2
   		Closed	Some#2
   	Reference-possible backup hold#1	Open	Some#2
   		Closed	No
   	Updatable backup hold#1	Open	No
   		Closed	Yes
   	Error shutdown	Open	No
   		Closed	No
   	No-log hold	Open	Some#3
   		Closed	Some#3
   	Initialization hold#1	Open	No#4
   		Closed	No#4
   	Online reorganization hold#1	Open	Some#5
   		Closed	Some#5

Legend:

Yes: Accessible

Some: Some SQL code accessible

No: Not accessible

#1

A temporary table RDAREA does not transition to this state.

#2

Only reference SQL can be accessed.

#3

Only PURGE TABLE of permanent base tables can be executed.

#4: Placed in lock-release wait status

#5: Other than the following, only SQL statements that access a current RDAREA while in the log acquisition mode can be executed:

• CREATE TABLE
• CREATE INDEX
• DROP TABLE
• DROP INDEX
• DROP SCHEMA
• ALTER TABLE
• PURGE TABLE
• LOCK