Oracle8 Migration Release 8.0 A58243-01 |
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# C
Version 8 INIT.ORA Changes

Version 8 supports new INIT.ORA initialization parameters, while some release 7.3 parameters have been changed or have become obsolete in version 8.

The following topics are covered in this appendix:

- COMPATIBLE Parameter
- Data Dictionary Protection
- DML_LOCKS
- NCHAR and NLS Parameters and Compatibility
- Pre-Version 8 Parameters Renamed in Version 8
- Release 7.3 Parameters Obsolete in Version 8
- REPLICATION_DEPENDENCY_TRACKING for the Replication Server
- Features No Longer Supported in Version 8

## COMPATIBLE Parameter

The COMPATIBLE parameter specifies the release with which the Oracle server must maintain compatibility. The COMPATIBLE parameter setting in your INIT.ORA file determines the functionality of your Oracle server; therefore, it is important to set it correctly.

However, you should set the COMPATIBLE parameter at a specific point in your migration, upgrading, or downgrading process. Therefore, follow the procedure in the appropriate chapter and set the COMPATIBLE parameter only when you are instructed to do so. After the operation is complete, you can set the COMPATIBLE parameter whenever necessary.

To check your current COMPATIBLE parameter setting, issue the following command:

    SVRMGR> SELECT name, value, description FROM v$parameter

    WHERE name="compatible";

WARNING: If you are migrating to version 8, make sure the COMPATIBLE parameter is not set to any version 7 release.

### Migrating or Upgrading to Release 8.0.4

If you are migrating or upgrading to release 8.0.4, the COMPATIBLE parameter is set to the following by default:

    COMPATIBLE=8.0.0.0.0

If you do not set the COMPATIBLE parameter at all, it is set to this value. This setting has the same effect as setting COMPATIBLE to 8.0.3.0.0 and allows you to downgrade to release 8.0.3 easily, if you choose to do that in the future.

However, if you use the default setting (8.0.0.0.0), you will not be able to use the following new features of release 8.0.4:

- Propagation in Advanced Queuing (AQ)
- Improved SCN Generation

To use these new release 8.0.4.0.0 features, set the COMPATIBLE parameter to the following:

    COMPATIBLE=8.0.4.0.0

Note: Once the COMPATIBLE parameter is set to 8.0.4.0.0, it may require more work to downgrade to a previous release. However, if you do not plan to downgrade to a previous release, Oracle Corporation recommends a setting of 8.0.4.0.0.

The following sections provide a brief overview of the new features that require a COMPATIBLE parameter setting of 8.0.4.0.0.

#### Propagation in Advanced Queuing (AQ)

Release 8.0.4 does not support distributed object types; therefore, you cannot implement remote enqueuing or dequeuing using a standard database link. However, in release 8.0.4, you can use AQ's message propagation to enqueue to a remote queue.

For example, you can connect to database X and enqueue the message in a queue, for example "DROPBOX" located in database X. You can configure AQ so that all messages enqueued in queue "DROPBOX" are automatically propagated to another queue in database Y, regardless of whether database Y is local or remote. AQ automatically checks if the type of the remote queue in database Y is structurally equivalent to the type of the local queue in database X, and propagates the messages.

Recipients of propagated messages can be either applications or queues. If the recipient is a queue, the actual recipients are determined by the subscription list associated with the recipient queue. If the queues are remote, messages are propagated using the specified DBLINK. Only AQ to AQ message propagation is supported.

See Also: The Oracle8 Application Developer's Guide for more information about propagation in AQ.

#### Improved SCN Generation

Release 8.0.4 implements an improved algorithm for System Change Number (SCN) generation. If you run Oracle Parallel Server with the INIT.ORA parameter MAX_COMMIT_PROPAGATION_DELAY set to less than 7 seconds, Oracle Corporation strongly recommends that you set COMPATIBLE to 8.0.4.0.0.

See Also: Oracle8 Concepts for more information about SCN generation.

## Data Dictionary Protection

O7_DICTIONARY_ACCESSIBILITY is the INIT.ORA parameter switch that continues version 7 data dictionary behavior. It is only a temporary expedient and is not planned for future version 8 releases.

## DML_LOCKS

Version 8 systems typically consume more DML locks while performing DDL operations than are required for version 7 systems. Nevertheless, the version 7 DML_LOCKS parameter default settings usually are adequate for version 8 systems, even for DML-intensive applications.

The default value of DML_LOCKS is a multiple of the number of transactions, which is calculated from the number of rollback segments. However, in version 8 fewer transactions are used per rollback segment than are used in version 7. Consequently, DML_LOCKS has a lower default value in version 8. Under some extreme test conditions, a version 8 system exceeded its (version 7) DML lock limit, and the DML_LOCKS parameter value had to be increased.

Also, you may need to adjust the TRANSACTION_PER_ROLLBACK_SEGMENT parameter setting, depending on the platform-specific settings. An informational message about this change may be displayed during database startup operations, for example at Step 12 in "Migration Steps in the Version 8 Environment" on page 3-15.

## NCHAR and NLS Parameters and Compatibility

You should set NLS_LANG to your environment, as follows:

- set ORA_NLS32 for 7.3.x environment
- set ORA_NLS33 for 8.0 environment

Verify that the client side has the correct NLS character set environment variables. An error is generated when Oracle 7.3 NLS code tries to load a version 8 character set.

## Pre-Version 8 Parameters Renamed in Version 8

The following initialization parameters have been renamed in version 8:

ASYNC_READ | DISK_ASYNCH_IO
ASYNC_WRITE | DISK_ASYNCH_IO
DB_FILE_STANDBY_NAME_CONVERT | DB_FILE_NAME_CONVERT
DB_WRITERS | DBWR_IO_SLAVES
LOG_FILE_STANDBY_NAME_CONVERT | LOG_FILE_NAME_CONVERT
SNAPSHOT_REFRESH_INTERVAL | JOB_QUEUE_INTERVAL
SNAPSHOT_REFRESH_PROCESS | JOB_QUEUE_PROCESSES
USE-ASYNC_IO | DISK_ASYNCH_IO

See Also: Oracle8 Reference for more information about initialization parameters.

Note: Some of the parameters listed above are platform-specific. See your platform-specific Oracle documentation for more information about renamed initialization parameters on your platform.

## Release 7.3 Parameters Obsolete in Version 8

The following parameters are obsolete in version 8:

CCF_IO_SIZE

CHECKPOINT_PROCESS

GC_DB_LOCKS

GC_FREELIST_GROUPS

GC_ROLLBACK_SEGMENTS

GC_SAVE_ROLLBACK_LOCKS

GC_SEGMENTS

GC_TABLESPACES

IO_TIMEOUT

INIT_SQL_FILES

IPQ_ADDRESS

IPQ_NET

LM_DOMAINS

LM_NON_FAULT_TOLERANT

OPTIMIZER_PARALLEL_PASS

PARALLEL_DEFAUILT_MAX_SCANS

PARALLEL_DEFAULT_SCAN_SIZE

SEQUENCE_CACHE_HASH_BUCKETS

SERIALIZABLE

SESSION_CACHED_CURSORS

UNLIMITED_ROLLBACK_SEGMENTS

USE_IPQ

USE_READV

USE_SIGIO

V733PLANS_ENABLED

See Also: Oracle8 Reference for more information about initialization parameters.

Note: Some of the parameters listed in this section are platform-specific. See your platform-specific Oracle documentation for more information about obsolete initialization parameters on your platform.

## REPLICATION_DEPENDENCY_TRACKING for the Replication Server

Use the REPLICATION_DEPENDENCY_TRACKING parameter for turning DSCN tracking on or off.

TRUE, the default value, turns dependency tracking ON for read/write operations to the database. Dependency tracking is essential for the Replication Server to propagate changes in parallel.

FALSE turns dependency tracking OFF. This condition allows read/write operations to the database to run faster, but it does not produce dependency information for the Replication Server to perform parallel propagations.

WARNING: If the application performs a read/write operation to any replicated table, do not set REPLICATION_DEPENDENCY_TRACKING to FALSE.

## Features No Longer Supported in Version 8

This section identifies features associated with INIT.ORA file parameters from previous Oracle versions/releases that are obsolete in version 8. Oracle support for these items will likely be dropped in future releases; therefore, they should be considered desupported in version 8.

### SERIALIZABLE=TRUE or _SERIALIZABLE

The INIT.ORA file parameter SERIALIZABLE=TRUE or _SERIALIZABLE implies automatic table-level locking ON READ in version 8. It should not be used in any version 8 installation and will probably be permanently deleted from the maintenance release after 8.1.

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