1 CHANGE_DATABASE Changes characteristics of the database root file and storage area files. When this statement executes, Oracle Rdb updates the characteristics named in the statement. All other characteristics remain the same. Example: RDO> CHANGE DATABASE FILENAME 'DISK2:[USER.TEST]PERSONNEL' cont> SNAPSHOT ALLOCATION IS 200. 2 More You need the Oracle Rdb ADMINISTRATOR privilege to use the CHANGE DATABASE statement. Use CHANGE DATABASE to: o Define, change, and delete storage areas in multifile databases o Enable or disable after-image journaling and change journal file characteristics o Enable or disable snapshot transactions and change snapshot file characteristics o Change a read/write storage area to read-only, or a read-only storage area to read/write o Change a storage area that contains only a segmented string to a format that can be stored on a write-once, read-many (WORM) device, using the WRITE_ONCE option. o Change the number of recovery buffers o Change physical parameters associated with the database o Specify whether the database can be opened automatically or manually o Require the use of the data dictionary o Enable or disable global buffers o Enable or disable fast commit processing o Enable or disable carry-over lock optimization o Set a database-wide timeout interval You cannot delete a storage area that is referred to in a storage map. 2 Examples Example 1 Use the CHANGE DATABASE statement to enable after-image journaling: CHANGE DATABASE PATHNAME 'PERSONNEL' JOURNAL FILE IS 'DEPT3:PERSONNEL.AIJ'. Example 2 You can also use CHANGE DATABASE to disable after-image journaling: RDO> CHANGE DATABASE FILENAME 'PERSONNEL' cont> NOJOURNAL. Example 3 The database shutdown feature is designed to ensure that active users on a single node or across a cluster cannot access the database while you perform administrative and maintenance tasks. For instance, use this shutdown feature when you need the database in a stable condition while performing backup and restore options, or when you are tuning the database. In the following example, a complete database shutdown is performed for all users of a database residing on a common disk in a cluster. The CHANGE DATABASE ... OPEN IS MANUAL statement is used to prevent new users from automatically opening that database when the first DML statement is executed on the database. $ RDO = "$RDO" $ RDO CHANGE DATABASE FILENAME "$222$DUA17:[DBS]PERS" OPEN IS MANUAL. $ REPLY/ALL "PERS.RDB database will be shut down in 15 minutes" $ REPLY/ALL "Please complete any work with PERS before then" $ WAIT 00:15:00.00 $ RMU/CLOSE/ABORT=FORCEX/CLUSTER $222$DUA17:[DBS]PERS At this point, you are assured that no unprivileged users can invoke this database. After opening the database with the RMU/OPEN/ACCESS=RESTRICTED command (the /ACCESS=RESTRICTED qualifier restricts database access to users with the DBADM privilege), you can perform maintenance tasks like tuning without interference from unprivileged users. For example, you can add or delete indexes and compare the performance results in a stable testing environment. When you are ready to make the database available again across the cluster, enter RDO and type: RDO> CHANGE DATABASE FILE "$222$DUA17:[DBS]PERS" cont> OPEN IS AUTOMATIC. Example 4 The following example shuts down access to a clusterwide database and then reopens the database for a specific node: $ RDO = "$RDO" $ RDO CHANGE DATABASE FILENAME "$222$DUA17:[DBS]PERS" OPEN IS MANUAL. $ REPLY/ALL "PERS.RDB database will be shut down in 15 minutes" $ REPLY/ALL "Please complete any work with PERS before then" $ WAIT 00:15:00.00 $ RMU/CLOSE/ABORT=FORCEX/CLUSTER $222$DUA17:[DBS]PERS $ ! $ SET HOST MADABT . . . $ ! On node MADABT now $ RMU/OPEN $222$DUA17:[DBS]PERS The RMU/OPEN command opens the PERS database on MADABT only. Users logged into other nodes in the cluster who normally have access to the clusterwide database cannot access it until: o The RMU/OPEN command is executed by a user with sufficient privilege on his or her node. o Or, the CHANGE DATABASE ... OPEN IS AUTOMATIC statement is executed by a user with sufficient privilege from any node in the cluster. Example 5 The following example shows how to disable snapshots on a database: RDO> CHANGE DATABASE FILENAME 'PERSONNEL' SNAPSHOT IS DISABLED. Example 6 The following example uses the CHANGE DATABASE statement to define a new storage area for a multifile database: RDO> CHANGE DATABASE FILENAME 'MF_PERSONNEL' cont> DEFINE STORAGE AREA ARCHIVED_EMPS cont> FILENAME DISK3:ARCHIVED_EMPS cont> ALLOCATION IS 50 PAGES cont> PAGE FORMAT IS MIXED cont> SNAPSHOT_FILENAME IS DISK4:ARCHIVED_EMPS cont> END ARCHIVED_EMPS STORAGE AREA. Example 7 This example uses the DICTIONARY IS REQUIRED option to enforce use of the data dictionary if metadata updates occur. Users must invoke the database with the PATHNAME argument to perform any metadata changes. Note that when you specify the DICTIONARY option, that is the only option you can specify in a CHANGE DATABASE statement. To specify other options, you must issue another CHANGE DATABASE statement. RDO> CHANGE DATABASE FILENAME 'PERSONNEL' cont> DICTIONARY IS REQUIRED. Example 8 This example uses the READ_ONLY clause to change the ARCHIVED_ EMPS storage area to a read-only storage area. RDO> CHANGE DATABASE FILENAME 'MF_PERSONNEL' cont> CHANGE STORAGE AREA ARCHIVED_EMPS cont> READ_ONLY. Example 9 This example uses the GLOBAL BUFFERS clause to enable global buffers for the MF_PERSONNEL database. RDO> CHANGE DATABASE FILENAME MF_PERSONNEL cont> GLOBAL BUFFERS ARE ENABLED cont> (NUMBER IS 50, cont> USER LIMIT IS 10). In this example, 50 is the number of global buffers and 10 is the maximum number (user limit) of global buffers per user. Example 10 This example enables fast commit processing with a transaction interval of 10, and specifies checkpoint intervals of 512 blocks and 12 seconds: RDO> CHANGE DATABASE FILENAME TEST1 cont> JOURNAL FAST COMMIT ENABLED cont> (CHECKPOINT INTERVAL IS 512 BLOCKS, cont> CHECKPOINT TIMED EVERY 12 SECONDS, cont> TRANSACTION INTERVAL IS 10). Example 11 This example disables the carry-over lock optimization: RDO> CHANGE DATABASE FILENAME TEST1 cont> CARRY OVER LOCKS ARE DISABLED. Example 12 This example sets the default database lock timeout interval to 25 seconds. This is the database wide timeout interval. It is used as the default as well as the upper limit in determining the timeout interval to use. For example, if LOCK TIMEOUT INTERVAL IS 25 SECONDS is specified with the CHANGE DATABASE or DEFINE DATABASE statement, and a user specifies 30 seconds with the SQL SET TRANSACTION WAIT 30 statement or sets the logical name RDM$BIND_LOCK_TIMEOUT_INTERVAL to 30, RDO would still use the interval of 25 specified with the LOCK TIMEOUT INTERVAL clause. The maximum number of seconds that can be specified with the LOCK TIMEOUT INTERVAL clause is 65,000: RDO> CHANGE DATABASE FILENAME TEST1 cont> CARRY OVER LOCKS ARE ENABLED cont> LOCK TIMEOUT INTERVAL IS 25 seconds. 2 Format (B)0CHANGE DATABASE qqqqqqqqq>qqqqqqqqqqqqqqqqqqqqqqqqqqqk lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqwqwq> FILENAME qq> file-spec qwqk mq> db-handle qq> = qj mq> PATHNAME qq> path-name qj x lqqqqqqqqqqqqqqqqqqqqqqqqqqqq change-database-options1 qqqqqqqqqqqqqqqqqqwqwq> . x tq> change-database-options2 qqqqqqqqqqqqqqqqqqu x x tq> change-journal-file-options qqqqqqqqqqqqqqqu x x tq> add-storage-area-clause qqqqqqqqqqqqqqqqqqqu x x tq> change-storage-area-clause qqqqqqqqqqqqqqqqu x x mq> DELETE STORAGE AREA qq> storage-area-name qj x mqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqwqwqqq> x tqq> OPEN IS qqqqqqqqqqqqwqq> AUTOMATIC qwqqqqqqqqqqqqqqqqqqqqu x x x mqq> MANUAL qqqqqj x x x tqq> NUMBER OF qqwq> CLUSTER qqqqwq> NODES IS number-nodes qqqqu x x x mq> VAXCLUSTER qj x x x x x x x tqq> NUMBER OF BUFFERS IS qqqq> number-buffers qqqqqqqqqqqqqqqqu x x tqq> NUMBER OF USERS IS qqqqqq> number-users qqqqqqqqqqqqqqqqqqu x x tqq> ADJUSTABLE LOCK GRANULARITY IS qwqq> ENABLED qqqwqqqqqqqqqu x x x mqq> DISABLED qqj x x x tqq> NUMBER OF RECOVERY BUFFERS IS qq> recovery buffers qqqqqqqu x x mqq> global-buffer-params qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj x mqqqqqqqqqqqqqqqqqqqqqqqqqqq specified 4). Had the DBA specified 2032 users and 50 nodes, 50 would be the maximum value for the number of nodes (specified 50 > calculated 41) and 50 TSNBLKs would be allocated, one for each node. As another example, if the DBA specifies 50 users and 10 nodes, the maximum value is 10 nodes (specified 10 > calculated 1), so ten TSNBLKs would be allocated, one for each node. This parameter can only be used with multifile databases. To make this change for a single-file database, first export the database using the SQL EXPORT statement and then specify the change in the SQL IMPORT statement. 4 number-buffers The number of buffers Oracle Rdb allocates per process using this database. Specify an unsigned integer between 2 and 32768. The default is 20 buffers. 4 number-users The maximum number of users allowed to access the database at one time. The default is 50 users. This parameter can only be used with multifile databases. To make this change for a single-file database, first export the database using the SQL EXPORT statement and then specify the change in the SQL IMPORT statement. 4 ADJUSTABLE_LOCK Enables or disables whether or not the database system will automatically maintain as few locks as possible on database resources. The default is ENABLED, and results in fewer locks against the database. However, if contention for database resources is high, the automatic adjustment of locks can become a CPU drain. Such databases can trade more restrictive locking for less CPU usage by disabling adjustable lock granularity. Disabling adjustable locking granularity may require that the OpenVMS SYSGEN parameters for locks be increased. 4 recovery-buffers The number of database buffers used during the automatic recovery process that is initiated after a system or process failure. Specify an unsigned integer between 2 and 32768. The default is 20 buffers. 4 global-buffer-params (B)0global-buffer-params= q> GLOBAL BUFFERS ARE qwq> ENABLED qqwqk mq> DISABLED qj x lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqwqq> mq> ( qq> NUMBER IS number-glo-buffers qq> , qk x lqqqqqqqqqqqqqqq USER LIMIT IS max-glo-buffers qq> ) qqqqqj 5 GLOBAL_BUFFERS The GLOBAL BUFFERS ARE ENABLED clause specifies that Oracle Rdb maintain one global buffer pool per node in the cluster for each database. By default, Oracle Rdb maintains a local buffer pool for each user. For more than one user to use the same page, each must read it from disk into their local buffer pool. When the GLOBAL BUFFERS ARE ENABLED clause has been specified, a page in the global buffer pool may be read by more than one user at the same time, although only one user reads the page from disk into the global buffer pool. Global buffering provides improved performance because I/O is reduced and memory is better utilized. The default is GLOBAL BUFFERS ARE DISABLED, in which Oracle Rdb maintains a local buffer pool for each user, and global buffers are not enabled. 5 NUMBER When global buffers are enabled, the NUMBER IS clause is used to specify the default number of global buffers per node. The default number of global buffers is the maximum number of users multiplied by 5. (In the RDO syntax for database parameters, a user is the same as an attach.) You can override the default by defining a value for the logical name RDM$BIND_ BUFFERS. Although you can change the NUMBER IS parameter online, the change will only take effect the next time that the database is opened. By default, a database can be opened automatically (that is, by any user who invokes the database and executes a data manipulation language statement). If the database was modified so that it must be manually opened, the RMU/OPEN command must be used to open it. 5 USER_LIMIT The USER LIMIT clause specifies the maximum number of global buffers each user allocates. Because global buffer pools are shared by all users, you must define an upper limit on how many global buffers a single user can allocate. This limit prevents a user from defining the RDM$BIND_BUFFERS to use all the buffers in the global buffer pool. The user limit cannot be greater then the total number of global buffers. The default is 5. See the Oracle Rdb Guide to Database Performance and Tuning for information on determining the maximum number of global buffers a user can allocate. Although you can change the USER LIMIT IS parameter online, the change will only take effect the next time that the database is opened. By default, a database can be opened automatically (that is, by any user who invokes the database and executes a data manipulation language statement). If the database was modified so that it must be manually opened, the RMU/OPEN command must be used to open it. 3 change-database-options2 (B)0change-database-options2 = qwqwqq>qqqqqqqqqqqqqqqqqqqqqq>qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqwqwq> x tqq> SNAPSHOT IS qqwq> ENABLED qwqqqqqqq>qqqqqqwqwqqqqqqqu x x x x tq> IMMEDIATE qu x x x x x x mq> DEFERRED qqj x x x x x mq> DISABLED qqqqqqqq>qqqqqqqqj x x x tqq> SNAPSHOT ALLOCATION IS q> snp-pages qq> PAGES qqqqqqu x x twq> SNAPSHOT EXTENT IS qwqqwq> extent-pages q> PAGES qwqu x x xmq> EXTENT IS qqqqqqqqqqj mq> (extension-options) qqqj x x x tqq> CARRY OVER LOCKS ARE qwq> ENABLED qqwqqqqqqqqqqqqqqqu x x x mq> DISABLED qj x x x tqq> LOCK TIMEOUT INTERVAL IS number-seconds SECONDS qqqqu x x tqq> READ_ONLY qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqu x x tqq> READ_WRITE qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqu x x tqq> DICTIONARY IS qqqqqqwq> REQUIRED qqqqqqqwqqqqqqqqqqqu x x x mq> NOT REQUIRED qqqj x x x mqq> journal-fast-commit-clause qqqqqqqqqqqqqqqqqqqqqqqqqj x mqqqqqqqqqqqqqqqqqq ( qqq> MINIMUM OF qq> min-pages qqq> PAGES, qk lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj mqq> MAXIMUM OF qq> max-pages qq> PAGES,qk lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj mqq> PERCENT GROWTH IS qqq> growth qqqq> ) qqq> 5 min-pages The minimum number of pages of each extent. The default is 99 pages. 5 max-pages The maximum number of pages of each extent. The default is 9,999 pages. 5 growth The percent growth of each extent. The default is 20 percent growth. 4 CARRY_OVER_LOCKS Enables or disables carry-over lock optimization. Carry-over locks are enabled by default. While attached to the database, a process can have some active locks (locks attached to the database) and some carry-over locks (locks requested in earlier transactions that have not been demoted). If a transaction needs a lock it has currently marked as carry-over, it can reuse the lock by changing it to an active lock. The same lock can go from active to carry-over to active multiple times without paying the cost of lock request and demotion. This results in a substantial reduction in the number of lock requests if a process accesses the same set of areas repeatedly. As part of the carry-over lock optimization, a NOWAIT transaction requests, acquires, and holds a NOWAIT lock. This signals other processes accessing the database that a NOWAIT transaction exists and causes Oracle Rdb to release all carry-over locks. If NOWAIT transactions are noticeably slow in executing, you can specify CARRY OVER LOCKS ARE DISABLED with the CHANGE DATABASE or DEFINE DATABASE statement. This feature is available as an online database modification. 4 LOCK_TIMEOUT Specifies the number of seconds for processes to wait during a lock conflict before timing out. The number of seconds can be between one and 65,000. The lock timeout interval is database-wide: it is used as the default as well as the upper limit in determining the timeout interval. For example, if LOCK TIMEOUT INTERVAL IS 25 SECONDS is specified with the CHANGE DATABASE or DEFINE DATABASE statement, and a user specifies SQL SET TRANSACTION WAIT 30 or sets the logical name RDM$BIND_LOCK_TIMEOUT_INTERVAL to 30, RDO would still use the interval 25 specified with the LOCK TIMEOUT INTERVAL clause. 4 READ_ONLY The READ_ONLY option is used to change a read/write RDB$SYSTEM storage area (and the Oracle Rdb system relations stored in the area) to read-only. You might choose the READ_ONLY option if your database is never or rarely updated. When the RDB$SYSTEM storage area is changed to read-only, locking conflicts occur less frequently, and the automatic updating of index and relation cardinality is inhibited. No write operation can be done in a read-only storage area except a cardinality update. See the RMU/ANALYZE/CARDINALITY help topic in the RMU help file for more information and restrictions on updating cardinalities. To change a storage area other than the RDB$SYSTEM storage area to read-only, or to change a database to read-only, use the READ_ ONLY option of the change-storage-area-clause. 4 READ_WRITE The READ_WRITE option is used to change a read-only RDB$SYSTEM storage area (and the Oracle Rdb system relations stored in the area) to read/write. Select the READ_WRITE option to change a read-only RDB$SYSTEM storage area to read/write. To change a storage area other than the RDB$SYSTEM storage area to read/write, or to change a database to read/write, use the READ_WRITE option of the change-storage-area-clause. 4 DICTIONARY Determines whether the database must be invoked by path name for data definition changes to occur. If you specify the DICTIONARY IS REQUIRED option, the database must be invoked by path name to change metadata and the data dictionary will be maintained. If you specify the DICTIONARY IS NOT REQUIRED option, the database can be invoked by either file name or path name to change metadata. The default is DICTIONARY IS NOT REQUIRED. If you specify the DICTIONARY option, you cannot specify any other options in the same CHANGE DATABASE statement. 4 journal-fast-commit-clause (B)0journal-fast-commit-clause= qq> JOURNAL FAST COMMIT qwq> ENABLED qqwqqqk mq> DISABLED qj x lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj mwqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqwq> m> ( qqwqwq> CHECKPOINT INTERVAL IS n BLOCKS qqqqqwqwq> ) qj x tq> CHECKPOINT TIMED EVERY n SECONDS qqqqu x x tq> COMMIT TO JOURNAL OPTIMIZATION qqqqqqu x x tq> NO COMMIT TO JOURNAL OPTIMIZATIONqqqqu x x mq> TRANSACTION INTERVAL IS number-txns qj x mqqqqqqqqqqqqqqqqqqq , CHANGE DATABASE FILENAME TEST1 cont> JOURNAL FILE IS TEST1_AIJ cont> JOURNAL FAST COMMIT ENABLED cont> (CHECKPOINT INTERVAL IS 512 BLOCKS, cont> CHECKPOINT TIMED EVERY 12 SECONDS). 5 COMMIT_TO_JOURNAL If you enable COMMIT TO JOURNAL OPTIMIZATION when you enable fast commit, Oracle Rdb does not write commit information to the database root file. This option enhances performance in database environments that are update intensive. Because of the prerequisites for enabling the journal optimization option, general use databases or databases that have many read- only transactions may not benefit from this feature. For more information see the Oracle Rdb Guide to Database Maintenance. Note that if you specify COMMIT TO JOURNAL OPTIMIZATION, you must disable or defer snapshots. If you change snapshots to enabled immediate, then you must disable COMMIT TO JOURNAL OPTIMIZATION. 5 TRANSACTION_INTERVAL The TRANSACTION INTERVAL IS n clause specifies the size of the TSN range where n equals the number of TSNs (transaction sequence numbers). Oracle Rdb uses transaction sequence numbers to ensure database integrity. When you specify NO COMMIT TO JOURNAL OPTIMIZATION, TSNs are assigned to users one at a time. When the journal optimization option is enabled, each user is pre-assigned a range of TSNs. Assigning a range of TSNs avoids the single- threading problem because commit information need not be written to the database root for each transaction. Oracle Rdb writes all transaction information to the .AIJ file except for each user's allocated TSN range, which it writes to the root. The transaction interval value (the TSN range) must be a number between 8 and 1024. The default value is 256. You need to decide which constraint has precedence on your database: performance or running out of TSNs. As a general guideline, if your database has few users or if all user sessions are long, select a high transaction interval. If your database has many users or if user sessions are short, select a smaller transaction interval. You can specify a transaction interval with JOURNAL FAST COMMIT IS DISABLED, but the interval will not be used until you enable the fast commit protocol. 3 change-journal-file-options (B)0change-journal-file-options = qwqwqqqqqqqqqqqqqqqqqqqqqqqqq>qqqqqqqqqqqqqqqqqqqqqqqqqqqqwqwq> x tq> JOURNAL FILE IS qq> aij-journal-file-spec qqqqqqqqqu x x tq> NOJOURNAL qqqqqqqqqqqqqqqqqqq>qqqqqqqqqqqqqqqqqqqqqu x x tq> JOURNAL ALLOCATION IS q> journal-blocks q> BLOCKS qu x x mq> JOURNAL EXTENT IS qqq> extent-blocks qq> BLOCKS qqqj x mqqqqqqqqqqqqqqqqqqqqqqqqqqq DEFINE STORAGE AREA qqqqqqq> storage-area-name qqqqqqqqqqqk lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq FILENAME qqqq> file-spec qqqwqqqqqqqqqqqqqqq>qqqqqqqqqqqwqqqk mqq> storage-area-options qqj x lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq END qqqwqqqqqqqqq>qqqqqqqqqqqwq> STORAGE AREA qqqq> mq>storage-area-name qj 4 storage-area-name The name of the storage area you want to create. 4 file-spec The file specification for the storage area file. By default, this file has the default file type RDA. 4 storage-area-options (B)0storage-area-options = qwwqqqqqqqqqqqqqqqqqqqqqqqqqqq>qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqwwq> xtqq> ALLOCATION IS qqq> number-pages qqqq>qqqqqqqqq PAGES qqqqux xtqq> PAGE SIZE IS qqqq> page-blocks qqqqq>qqqqqqqqq BLOCKS qqqux xtqq> PAGE FORMAT IS qqwqqqq> UNIFORM qqqqwqqqqqqqqqqqqqqqqqqqqux xx mqqqq> MIXED qqqqqqj xx xtqq> THRESHOLDS ARE q> ( q> val1 wqqqqqqqqqqqqqqqqqqqqwq> ) qqux xx m> ,val2 wqqqqqqqqqwqj xx xx m> ,val3 qj xx xtqq> INTERVAL IS qqqqqqq> number-data-pages qqqqqqqqqqqqqqqqqqux xtqq> SNAPSHOT_FILENAME IS qqqq> file-spec qqqqqqqqqqqqqqqqqqqqux xtqq> SNAPSHOT ALLOCATION IS qqq> snp-pages qqq> PAGES qqqqqqqqux xtwq> SNAPSHOT EXTENT IS qwqqwq> extent-pages qqqq> PAGES qwqqqux xxmq> EXTENT IS qqqqqqqqqqj mq> extension-options qqqqqqqqj xx xmqq> WRITE_ONCE qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqjx mqqqqqqqqqqqqqqqqqqqqqqqqqqqq ( qqq> MINIMUM OF qq> min-pages qqq> PAGES, qk lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj mqq> MAXIMUM OF qq> max-pages qq> PAGES,qk lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj mqq> PERCENT GROWTH IS qqq> growth qqqq> ) qqq> o min-pages Specifies the minimum number of pages of each extent. The default is 99 pages o max-pages Specifies the maximum number of pages of each extent. The default is 9,999 pages. o growth Specifies the percent growth of each extent. The default is 20 percent growth. 3 change-storage-area-clause Allows you to modify the extent and snapshot allocation of a storage area. You cannot specify RDB$SYSTEM in the change- storage-area-clause. To change the EXTENT, SNAPSHOT ALLOCATION, or SNAPSHOT EXTENT for RDB$SYSTEM, specify these qualifiers as part of the change-database-options. When you specify these options as part of the change-database-options, they will be changed for RDB$SYSTEM but not for any other storage areas. (B)0change-storage-area-clause = qqqqqq> CHANGE STORAGE AREA qqqqqqqq> storage-area-name qqqqqk lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqwqwqwqq> x x tq> READ_WRITE qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqu x x x x tq> EXTENT IS qw> extent-pages qqqqqqqq PAGES qwqqqqqu x x x x x m> extension-options qqqqqqqqqqqj x x x x x tq> SNAPSHOT ALLOCATION IS qq> snp-pages qqq> PAGES qu x x x x mq> SNAPSHOT EXTENT IS qw> extent-pages qq> PAGES qwqj x x x x m> (extension-options) qqqqj x x x mqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq READ_ONLY qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqu mqqqqq> WRITE_ONCE qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj 4 storage-area-name The name of the storage area that you want to modify. 4 READ_WRITE Used to change any read-only storage area (except the RDB$SYSTEM storage area) to a read/write storage area. To change a read-only RDB$SYSTEM storage area to read/write, you must use the READ_WRITE option of the change-database-options2 clause. 4 snp-pages Specifies the number of pages allocated for the snapshot file. The default is 100 pages. 4 extent-pages Specifies the number of pages of each extent. The default is 100 pages. 4 extension-options Specifies the MIN, MAX, and percent growth of each database file extent. Enclose the parameter list in parentheses. (B)0extension-options = qqq> ( qqq> MINIMUM OF qq> min-pages qqq> PAGES, qk lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj mqq> MAXIMUM OF qq> max-pages qq> PAGES,qk lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj mqq> PERCENT GROWTH IS qqq> growth qqqq> ) qqq> 5 min-pages Specifies the minimum number of pages of each extent. The default is 99 pages. 5 max-pages Specifies the maximum number of pages of each extent. The default is 9,999 pages. 5 growth Specifies the percent growth of each extent. The default is 20 percent growth. 4 READ_ONLY Used to change any read/write storage area (except the RDB$SYSTEM storage area) to a read-only storage area. To change a read/write RDB$SYSTEM storage area to read-only, you must use the READ_ONLY option of the change-database-options2 clause. You cannot change the parameters of a read-only storage area. You must first change the storage area to a read/write area, then change the parameters. Also, no write operation can be done in a read-only storage area except a cardinality update. See the RMU/ANALYZE/CARDINALITY help topic in the RMU help file for more information and restrictions on updating cardinalities. 4 WRITE_ONCE You can use the WRITE_ONCE option to change a storage area containing stable segmented string data to a format that can be stored on a write-once, read-many (WORM) optical disk. A WORM optical disk offers a relatively inexpensive way of storing large amounts of data for read-only access compared to other storage media. The following restrictions apply to the WRITE_ONCE option: o Note that you cannot write data other than segmented strings to a write-once storage area. Oracle Rdb issues an error message if you try to create a storage map that stores data other than segmented strings in a write-once storage area. Storage maps for non-segmented-string data must be removed before you can alter a storage area to WRITE_ONCE. o When you create a storage area on WORM media, you must specify that the snapshot area remains on read/write media: do not give a snapshot file the WRITE_ONCE attribute. o If you specify the WRITE_ONCE option when storing a segmented string, database keys are not compressed. For more information on database key compression, see the Oracle Rdb Guide to Database Maintenance. o Write-once storage areas do not use SPAM pages to look for storage space, but to assist moving data back to non-WORM media in which SPAM pages must be built again, space is still allocated for them. Since SPAM pages are essential in uniform areas, Write-once storage areas cannot be of uniform format and therefore are required to be of mixed format. o You can use the PAGE SIZE IS clause of CREATE STORAGE AREA to change the default page size for a storage area. To optimize storage, always specify an even number of blocks per page. o Rdb does not support magnetic media for storing write-once storage areas. o After you move a storage area to or from a WORM device, Do a full and complete backup of your database with the RMU/BACKUP command and start a new after-image journaling file. For more information on backup and recovery procedures with write-once storage areas, see the Oracle Rdb Guide to Database Maintenance. 3 DELETE_STORAGE_AREA Deletes the named storage area. You cannot delete the RDB$SYSTEM storage area. You cannot delete a storage area if a storage map refers to it, or if there is data in it.