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Oracle® Database Upgrade Guide
11g Release 2 (11.2)

Part Number E17222-04
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A Behavior Changes

This appendix documents important changes in behavior between Oracle9i Release 2 (9.2), Oracle Database 10g Release 1 (10.1), Oracle Database 10g Release 2 (10.2), Oracle Database 11g Release 1 (11.1), and Oracle Database 11g Release 2 (11.2). This appendix focuses on behavior changes that require a database administrator (also referred to as a DBA) to make an informed decision to minimize the risks that may be introduced by the changes. This appendix does not describe all changed behavior or new features in the new Oracle Database 11g release.

This appendix includes the following topics:

See Also:

Note:

Some of the initialization parameters listed in this appendix are operating system-specific. See your operating system-specific Oracle documentation for more information about these initialization parameters.

Compatibility and Interoperability Issues in Oracle Database 11g Release 2 (11.2)

The topics in this section describe compatibility and interoperability issues introduced in Oracle Database 11g Release 2 (11.2) and actions you can take to prevent problems resulting from these changes.

Planned De-support of Change Data Capture

Oracle Change Data Capture will be de-supported in a future release of Oracle Database and will be replaced with Oracle GoldenGate. Therefore, Oracle strongly recommends that you use Oracle GoldenGate for new applications.

For Oracle Database 11g Release 2 (11.2), Change Data Capture continues to function as in earlier releases. If you are currently using Change Data Capture, then you will be able to continue to do so for the foreseeable future. However, Change Data Capture will not be further enhanced, and will only be supported based on the current, documented functionality.

See Also:

http://www.oracle.com/technology/products/goldengate/ on Oracle Technology Network for more information about Oracle GoldenGate

Initialization Parameters Deprecated in Oracle Database 11g Release 2 (11.2)

The following initialization parameters were deprecated in Oracle Database 11g Release 2 (11.2). To get a list of all deprecated initialization parameters, issue the following SQL statement:

SQL> SELECT name FROM v$parameter
         WHERE isdeprecated = 'TRUE';

A deprecated parameter behaves the same way as a regular parameter, except that a warning message is displayed at instance startup if a deprecated parameter is specified in the parameter file. In addition, all deprecated parameters are logged to the alert log at instance startup.


ACTIVE_INSTANCE_COUNT
PARALLEL_IO_CAP_ENABLED

Initialization Parameters Obsolete in Oracle Database 11g Release 2 (11.2)

The following initialization parameters were made obsolete in Oracle Database 11g Release 2 (11.2).

Note:

An attempt to start a database using one or more obsolete initialization parameters will succeed, but a warning is returned and recorded in the alert log.

DRS_START
GC_FILES_TO_LOCKS
MAX_COMMIT_PROPAGATION_DELAY
PLSQL_NATIVE_LIBRARY_DIR
PLSQL_NATIVE_LIBRARY_SUBDIR_COUNT
SQL_VERSION

Static Data Dictionary Views Deprecated in Oracle Database 11g Release 2 (11.2)

The following static data dictionary views were deprecated in Oracle Database 11g Release 2 (11.2).


DBA_COMPARISON_SCAN_SUMMARY (replaced by DBA_COMPARISON_SCAN)
USER_COMPARISON_SCAN_SUMMARY (replaced by USER_COMPARISON_SCAN)

Dynamic Performance Views Deprecated in Oracle Database 11g Release 2 (11.2)

The following dynamic performance views were deprecated in Oracle Database 11g Release 2 (11.2).


V$FLASH_RECOVERY_AREA_USAGE (replaced by V$RECOVERY_AREA_USAGE)

Deprecated Features in Oracle Database 11g Release 2 (11.2)

This section lists Oracle Database features deprecated in Oracle Database 11g Release 2 (11.2). They are supported in this release for backward compatibility. However, Oracle recommends that you migrate away from these deprecated features.

  • Dictionary-managed tablespaces

    Oracle recommends that you create locally managed tablespaces. Locally managed tablespaces are much more efficiently managed than dictionary-managed tablespaces.

Changes to LOG_ARCHIVE_DEST_n Parameters

Starting with Oracle Database 11g Release 2 (11.2), the number of supported destinations in the LOG_ARCHIVE_DEST_n and the LOG_ARCHIVE_DEST_STATE_n parameters have been increased from 10 to 31. Destinations LOG_ARCHIVE_DEST_11 through LOG_ARCHIVE_DEST_31 do not support the SYNC, ARCH, LOCATION, MANDATORY, ALTERNATE, or DEPENDENCY attributes, and cannot be specified as the target of the ALTERNATE or DEPENDENCY attributes.

LOG_ARCHIVE_DEST_11 through LOG_ARCHIVE_DEST_31 can only be used when the COMPATIBLE initialization parameter is set to 11.2.0 or higher.

Compatibility and Interoperability Issues in Oracle Database 11g Release 1 (11.1)

The following sections describe compatibility and interoperability issues introduced in Oracle Database 11g Release 1 (11.1) and actions you can take to prevent problems resulting from these issues.

Initialization Parameters Deprecated in Oracle Database 11g Release 1 (11.1)

The following initialization parameters were deprecated in Oracle Database 11g Release 1 (11.1). To get a list of all deprecated initialization parameters, issue the following SQL statement:

SQL> SELECT name FROM v$parameter
         WHERE isdeprecated = 'TRUE';

A deprecated parameter behaves the same way as a regular parameter, except that a warning message is displayed at instance startup if a deprecated parameter is specified in the parameter file. In addition, all deprecated parameters are logged to the alert log at instance startup.


BACKGROUND_DUMP_DEST (replaced by DIAGNOSTIC_DEST)
COMMIT_WRITE
CURSOR_SPACE_FOR_TIME
INSTANCE_GROUPS
LOG_ARCHIVE_LOCAL_FIRST
PLSQL_DEBUG (replaced by PLSQL_OPTIMIZE_LEVEL)
PLSQL_V2_COMPATIBILITY
REMOTE_OS_AUTHENT
RESOURCE_MANAGER_CPU_ALLOCATION
STANDBY_ARCHIVE_DEST
TRANSACTION_LAG attribute (of the CQ_NOTIFICATION$_REG_INFO object)
USER_DUMP_DEST (replaced by DIAGNOSTIC_DEST)

Initialization Parameters Obsolete in Oracle Database 11g Release 1 (11.1)

The following initialization parameters were made obsolete in Oracle Database 11g Release 1 (11.1).

Note:

An attempt to start a database using one or more obsolete initialization parameters will succeed, but a warning is returned and recorded in the alert log.

DDL_WAIT_FOR_LOCKS
LOGMNR_MAX_PERSISTENT_SESSIONS
PLSQL_COMPILER_FLAGS

Static Data Dictionary Views with Dropped Columns in Oracle Database 11g Release 1 (11.1)

The following static data dictionary view columns were dropped in Oracle Database 11g Release 1 (11.1):

Static Data Dictionary View Dropped Columns
V$DATAFILE PLUGGED_IN

Deprecated Features in Oracle Database 11g Release 1 (11.1)

This section lists Oracle Database features deprecated in Oracle Database 11g Release 1 (11.1). They are supported in this release for backward compatibility. However, Oracle recommends that you migrate away from these deprecated features.

  • Oracle Ultra Search

  • Java Development Kit (JDK) 1.4

    Oracle recommends that you use JDK 5.0; but JDK 1.5 is also fully supported.

  • CTXXPATH index

    Oracle recommends that you use XMLIndex instead.

Automatic Maintenance Tasks Management

Automatic Maintenance Tasks Management, a new database component in Oracle Database 11g Release 1 (11.1), schedules all automatic maintenance tasks in an expanded set of maintenance windows. Automatic Maintenance Tasks Management enables you to exercise finer control over maintenance task scheduling for tasks such as optimizer statistics gathering, Segment Advisor, and Automatic SQL Tuning Advisor.

Automatic Maintenance Tasks Management uses all existing maintenance windows (for example, windows that are current members of the MAINTENANCE_WINDOW_GROUP. Existing resource plans associated with the maintenance windows are used. However, AUTOTASK_CONSUMER_GROUP is replaced in the resource plans by the AutoTask Resource Subplan.

If you disable either Optimizer Statistics Gathering or Segment Advisor jobs in 10g, then the corresponding Automatic Maintenance Tasks Management feature is disabled after upgrading to Oracle Database 11g Release 1 (11.1).

The following list shows the default settings for maintenance tasks:

  • Online backup is disabled

  • Optimizer Statistics Gathering is on

  • Segment Advisor is on

  • Automatic SQL Tuning is off

All other Automatic Maintenance Tasks Management clients are enabled by default.

Although Automatic Maintenance Tasks Management is automatically enabled when upgrading to Oracle Database 11g Release 1 (11.1), AutoTask online backup is not enabled automatically. You must configure online backup manually, if desired, after upgrading the database. If you perform a database downgrade, then Automatic Maintenance Tasks Management reverts to the default behavior for that release.

See Also:

The Oracle Database Administrator's Guide for complete information about the Automatic Maintenance Tasks Management feature

New SYSASM Privilege and OSASM Group for ASM Administration

Oracle Database 11g Release 1 (11.1) introduces a new SYSASM privilege that is specifically intended for performing ASM administration tasks. Using the SYSASM privilege instead of the SYSDBA privilege provides a clearer division of responsibility between ASM administration and database administration.

Warning messages will appear in the ASM alert.log if SYSDBA performs disk group maintenance (CREATE DISKGROUP, MOUNT/DISMOUNT, ADD/DROP DISK, ONLINE/OFFLINE DISK, DROP DISKGROUP). These tasks are deprecated for SYSDBA; they should be performed by SYSASM.

OSASM is a new operating system (OS) group that is used exclusively for ASM. Members of the OSASM group can connect AS SYSASM using OS authentication and have full access to ASM.

This feature is described in more detail in "Upgrading System Authentication for Oracle ASM Instances".

See Also:

Oracle Database Storage Administrator's Guide for more information about accessing ASM instances

ASM Disk Group Compatibility

Starting with Oracle Database 11g Release 1 (11.1), you can advance the Oracle Database and the ASM disk group compatibility settings across software versions. Using the new compatibility attributes, compatible.rdbms and compatible.asm, you can specify the minimum software version required to use the disk group for the database and the disk group for ASM, respectively.

This feature enables heterogeneous environments with disk groups from Oracle Database 10g Release 1 (10.1), Oracle Database 10g Release 2 (10.2), and Oracle Database 11g Release 1 (11.1). By default, both attributes are set to 10.1. You must advance these attributes to take advantage of the new features.

See Also:

Oracle Database Storage Administrator's Guide for more information on ASM disk group compatibility

COMPUTE STATISTICS and ESTIMATE STATISTICS Clauses

In earlier releases, the ANALYZE...COMPUTE STATISTICS and ANALYZE...ESTIMATE STATISTICS clauses could be used to start or stop the collection of statistics on an index. These clauses have been made obsolete. Oracle Database 11g Release 1 (11.1) automatically collects statistics during index creation and rebuild. These clauses are no longer supported and using them causes errors.

Oracle Data Mining Models and the DMSYS Schema Objects

During the upgrade to Oracle Database 11g Release 1 (11.1), DMSYS schema objects along with user models residing in user schemas are upgraded from any previous release without major constraints. Upon completion of the upgrade, the mining metadata is migrated into the SYS schema while the user models continue functioning with the new metadata. Oracle recommends that you drop the DMSYS schema after setting the COMPATIBLE initialization parameter to 11.0.0. In addition, the DBA will need to grant the new CREATE MINING MODEL privilege so that existing users can continue to build mining models.

Data mining models residing in a user schema are automatically upgraded as part of the model upgrade, which is an integral part of the Oracle Database upgrade process. Data mining model Export and Import utilities can also be used as a means of upgrading data mining models from one release to another.

During the database downgrade process, the data mining component is downgraded to a previous release. The downgrade process reloads DMSYS objects such as packages, types, and table objects as well as downgrading model objects residing in user schemas (if any). Objects that were created as a part of the database upgrade are removed from the SYS schema during the downgrade procedure. The process is transparent and does not require any user intervention.

After upgrading (and dropping the DMSYS schema after setting the COMPATIBLE initialization parameter to 11.0.0), importing models that were exported from Oracle Database 10g Release 1 (10.1) might have some complications due to their reference to the now nonexistent DMSYS schema. To handle this case, Oracle provides scripts to sufficiently (and minimally) mimic the DMSYS interface present in the Oracle Database 10g Release 1 (10.1) database so that the Import process can proceed. This is not a common occurrence because models become stale over time and users typically want to rebuild their models rather than import older ones.

Note that Data Mining is not protected by the COMPATIBLE initialization parameter. If COMPATIBLE is set at 10.1.0 or 10.2.0 while the database has been upgraded to Oracle Database 11g Release 1 (11.1), then all new and existing Data Mining features and functions should work. If you have built new mining models that are only available in Oracle Database 11g Release 1 (11.1), and subsequently decide to downgrade the database to Oracle Database 10g Release 2 (10.2), you will be required to drop the new mining models before downgrading.

Oracle Data Mining Scoring Engine

Starting with Oracle Database 11g Release 1 (11.1), the Oracle Data Mining Scoring Engine can no longer be installed.

SQL Plan Management and Control of SQL Plan Baselines

The use of stored outlines is deprecated in Oracle Database 11g Release 1 (11.1). Instead, you should use the SQL plan management feature that enables the optimizer to maintain a history of execution plans for a SQL statement. Using the execution plan history, the optimizer is able to detect a new plan representing a plan change for a SQL statement. When the optimizer detects a new plan, it stores the new plan and marks it for performance evaluation and uses the old (currently known good) plan. The optimizer uses the new plan only after its performance is verified to be better than that of the old plan. A SQL plan baseline consists of a set of known good plans for a SQL statement.

Migration of SQL Profiles

SQL Profiles are SQL management objects that were introduced in Oracle Database 10g Release 1 (10.1). These objects resided in a section of the dictionary that was defined in SYSTEM tablespace. The dictionary tables storing the SQL profiles are restructured to accommodate the storage of SQL plan baselines, which are also SQL management objects. Further, these dictionary tables are now defined in the SYSAUX tablespace.

When you upgrade from Oracle Database 10g Release 1 (10.1) to Oracle Database 11g Release 1 (11.1), the database upgrade script moves existing SQL profiles from the SYSTEM tablespace to the SYSAUX tablespace. Thus, if an Oracle Database 11g Release 1 (11.1) database instance is up but the SYSAUX tablespace is offline, then the optimizer is not able to access SQL Management objects, which can affect the performance on some of the SQL workload. In contrast, in Oracle Database 10g Release 1 (10.1), because SQL profiles were stored in SYSTEM tablespace, the unavailability of SQL profiles did not exist. Note that starting with Oracle Database 11g Release 1 (11.1), taking the SYSAUX tablespace offline can have potential SQL performance consequences.

Backward Compatibility

In Oracle Database 11g Release 1 (11.1):

  • If a stored outline for a SQL statement is active for the user session (for example, the stored outline category matches with the user session category), then the statement is compiled using the stored outline.

  • If a private outline is available for a SQL statement, then the statement is compiled using the private outline.

If a stored outline is available for a SQL statement, then the SQL Plan Management feature is not used. However, if another user session uses the same SQL statement but without an active stored outline, then the SQL plan management feature is used.

See Also:

Binary XML Support for Oracle XML Database

The binary XML storage option that is new in Oracle Database 11g Release 1 (11.1) is available when the COMPATIBLE initialization parameter is set to 11.0.0 or higher. When you create a table or column with this storage option, the minimum compatibility requirement is checked. This also applies when storing binary XML documents directly in the XML DB repository.

When Upgrading to Oracle Database 11g Release 1 (11.1)

When the database is upgraded to Oracle Database 11g Release 1 (11.1), none of the existing user XMLType tables and instances is modified in any fashion. Existing tables can be altered and new tables can be subsequently created using the new storage format after the upgrade is completed. The XDB tables XDB$CONFIG and XDB$ACL and the corresponding XML schemas are migrated to binary XML storage when a database is upgraded to Oracle Database 11g Release 1 (11.1).

PL/SQL Native Compilation and Access Control for Network Utility Packages

The following sections describe compatibility and interoperability changes introduced in PL/SQL for Oracle Database 11g Release 1 (11.1).

PL/SQL Native Compilation

Starting with Oracle Database 11g, PL/SQL Native Compilation does not need a C compiler. Therefore, if you presently use a C compiler only to support PL/SQL Native Compilation, you can remove it from the machine where your database is installed (and from each node in an Oracle RAC configuration).

Moreover, the output of PL/SQL Native Compilation is no longer materialized on the file system. There, the Oracle Database 10g initialization parameters PLSQL_Native_Library_Dir and PLSQL_Native_Library_Subdir_Count have no significance in Oracle Database 11g. The directories that they denoted, and the contents of these directories, can be safely deleted on completion of the upgrade process.

Further, the SPNC_COMMANDS file (in the ORACLE_HOME/plsql directory) is no longer needed.

Only one initialization parameter, PLSQL_Code_Type, remains for controlling PL/SQL Native Compilation. The DBA, therefore, no longer needs to have any interest in PL/SQL Native Compilation.

Access Control for Network Utility Packages

The default behavior for access control to network utility packages has been changed to disallow network operations to all nonprivileged users. This default behavior is different from, and is incompatible with, previous versions of Oracle Database.

For database users upgrading to Oracle Database 11g Release 1 (11.1), applications that depend on the PL/SQL network utility packages compile without any issues. However, at runtime the applications might receive exceptions when attempting to perform privileged network operations. Although you can restore the compatibility by using a wildcard to grant those privileges to perform any network operations to PUBLIC, Oracle strongly advises that database administrators carefully review each situation on an individual basis and grant privileges only as needed.

Note:

Oracle XML DB is required to properly maintain the access control lists. If Oracle XML DB is not already installed on the system, then you must install it during the upgrade procedure.

PL/SQL Control Parameters

The behavior of some of the Oracle parameters which control the behavior of PL/SQL changes in Oracle Database 11g Release 1 (11.1):

  • If PL/SQL debug code generation mode is selected by any parameter setup, then native code generation is turned off.

  • Debug code generation is on if the PLSQL_OPTIMIZE_LEVEL <= 1.

  • PLSQL_DEBUG is deprecated.

    You should use PLSQL_OPTIMIZE_LEVEL instead. A deprecation warning is issued if PLSQL_DEBUG is used.

  • If PLSQL_OPTIMIZE_LEVEL <= 1, then native code generation is turned off.

  • PLSQL_COMPILER_FLAGS is obsolete. It has no effect any longer and draws an error message that an illegal option is being set.

  • PLSQL_V2_COMPATIBILITY is deprecated.

Change in WebDAV ACL Evaluation Rules in Oracle XML DB

Oracle XML DB uses a security mechanism that is based on access-control lists (ACLs) to restrict access to any Oracle XML DB resource. An ACL is a list of access-control entries (ACEs) that determine which users, roles, and groups have access to a given resource.

There have been changes to the treatment of WebDAV ACL entries. Prior to Oracle Database 11g Release 1 (11.1), a <deny> entry always trumped any <allow> entry in a given ACL. Starting with Oracle Database 11g Release 1 (11.1), ACE order is irrelevant. The default behavior is determined only by the first <allow> or <deny> entry that is encountered. That is, the first entry determines the behavior for that principal and additional ACEs for that principal have no effect.

This change in the default behavior is different from, and is incompatible with, previous versions of Oracle Database. When upgrading to Oracle Database 11g Release 1 (11.1), you can get the same behavior as in previous releases by manually reordering the ACLs (if necessary). That is, if there are any ACLs that have <allow> followed somewhere by <deny>, then you should (manually) reorder the ACLs so that the <deny> entry occurs first.

See Also:

Oracle XML DB Developer's Guide for more information about the ACL evaluation rules

Summary Management and SQL Access Advisor

Starting with Oracle Database 10g Release 2 (10.2), the DBMS_OLAP package, which is the Summary Advisor in Summary Management, is being deprecated and has been replaced by the SQL Access Advisor.

SQL Access Advisor Tasks

Due to internal structural changes to the SQL Access Advisor repository, a database upgrade resets all existing SQL Access Advisor tasks to their initial state. This effectively deletes all recommendation information for tasks that have successfully executed prior to upgrade.

After upgrade, the recommendation information can be restored by re-executing the existing SQL Access Advisor tasks.

Standard Edition Starter Database

When the Standard Edition (SE) starter database is upgraded, the following components cannot be upgraded by the SE server because they require options that are not installed in the Standard Edition:

  • OLAP Catalog

  • OLAP Analytic Workspace

  • Oracle OLAP API

After the upgrade, these components have a STATUS value of 'OPTION OFF' in the DBA_REGISTRY view, and there will be some invalid objects in the associated component schemas. The Database Upgrade Assistant (DBUA) shows unsuccessful upgrades for these components.

Core Dump Location

On UNIX systems, when an application program crashes due to an unhandled signal, such as a segmentation fault, a core dump file is usually generated. The system default file name for this file is core, and it is located in the directory in which the application is currently running.

Starting with Oracle Database 11g Release 1 (11.1), applications using the Oracle Call Interface (OCI) can create a subdirectory named core_process_id, where process_id is the UNIX ID of the process that crashed. The core file is then placed in that subdirectory instead of the location where the application is running.

In sqlnet.ora, setting DIAG_SIGHANDLER_ENABLED = TRUE also puts the generated core file in the directory named core_process_id.

New Default Value for UNDO_MANAGEMENT

Starting with Oracle Database 11g Release 1 (11.1), the default value of the UNDO_MANAGEMENT parameter is AUTO so that automatic undo management is enabled by default. You must set the parameter to MANUAL to turn off automatic undo management, if required.

The UNDO_MANAGEMENT and ROLLBACK_SEGMENTS initialization parameters have changed from basic initialization parameters to non-basic initialization parameters. Most databases should be required to have only basic parameters set to run properly and efficiently.

See Also:

UNDO_MANAGEMENT in Oracle Database Reference

LOG_ARCHIVE_DEST_n Parameters

Starting with Oracle Database 11g Release 1 (11.1), the LOG_ARCHIVE_DEST_n parameter can be used to specify a local archiving destination on a database instance running Oracle Standard Edition. Previously, this parameter could only be specified on a database instance running Oracle Enterprise Edition.

SHARED_POOL_SIZE Parameter

Migration utilities for this release recommend new values for SHARED_POOL_SIZE based on the value of internal SGA overheads in the pre-upgrade environment, which you can determine by running the following query before upgrading to Oracle Database 11g Release 1 (11.1):

SQL> SELECT SUM(BYTES) FROM v$sgastat WHERE pool = 'shared pool';

In Oracle Database 11g Release 1 (11.1), the exact value of internal SGA overhead, or Startup overhead in Shared Pool, is listed in the new v$sgainfo view.

In manual SGA mode, values of SHARED_POOL_SIZE that are too small to accommodate the internal SGA overhead result in an ORA-00371 error during startup. This generated error message includes a suggested value for the SHARED_POOL_SIZE parameter. If you are using automatic shared memory management, the size of the shared pool is tuned automatically, and the ORA-00371 error is never generated.

The amount of shared pool memory allocated by Oracle Database releases before Oracle Database 10g Release 1 (10.1) was equal to the sum of the value of the SHARED_POOL_SIZE initialization parameter and the internal SGA overhead computed during instance startup. This overhead was based on the values of several other initialization parameters.

For example, if the SHARED_POOL_SIZE parameter is 64 megabytes and the internal SGA overhead is 12 megabytes, then the real size of shared pool in the SGA would be 76 megabytes, although the value of the SHARED_POOL_SIZE parameter would still be displayed as megabytes.

Starting with Oracle Database 10g Release 1 (10.1), the size of internal SGA overhead is included in the value of the SHARED_POOL_SIZE parameter. The shared pool memory allocated at startup is exactly the value of SHARED_POOL_SIZE. Therefore, this parameter must be set such that it includes both the internal SGA overhead and the desired effective value of the shared pool size.

Assuming that the internal SGA overhead remains unchanged, the effective available value of shared pool after startup would be 12 megabytes less than the value of the SHARED_POOL_SIZE parameter, or 52 megabytes. To maintain 64 megabytes for the effective value of shared pool memory, set the parameter to 76 megabytes.

JOB_QUEUE_PROCESSES Parameter

Beginning with Oracle Database 11g Release 1 (11.1), the JOB_QUEUE_PROCESSES parameter is changed from a basic to a non-basic initialization parameter. Most databases only need to have basic parameters set in order to run properly and efficiently. The default value is also changed from 0 to 1000.

Starting with Oracle Database 11g Release 2 (11.2), setting JOB_QUEUE_PROCESSES to 0 causes both DBMS_SCHEDULER and DBMS_JOB jobs to not run. Previously, setting JOB_QUEUE_PROCESSES to 0 caused DBMS_JOB jobs to not run, but DBMS_SCHEDULER jobs were unaffected and would still run.

See Also:

Oracle Database Reference for more information on this parameter

Automatic Diagnostic Repository

The locations of alert logs and trace files are no longer set by the initialization parameters BACKGROUND_DUMP_DEST and USER_DUMP_DEST. They are now kept in the Automatic Diagnostic Repository (ADR), whose location is set the by the initialization parameter DIAGNOSTIC_DEST.

See Also:

Oracle Database Administrator's Guide for more information on the management of diagnostic information

Compatibility and Interoperability Issues in Oracle Database 10g Release 2 (10.2)

The following sections describe compatibility and interoperability issues introduced in Oracle Database 10g Release 2 (10.2). If you are upgrading to Oracle Database 11g Release 1 (11.1) from a release prior to Oracle Database 10g Release 2 (10.2), then see the following sections for information about actions you can take to prevent problems resulting from these issues:

Initialization Parameters Deprecated in Oracle Database 10g Release 2 (10.2)

The following initialization parameters were deprecated in Oracle Database 10g Release 2 (10.2). To get a list of all deprecated initialization parameters, issue the following SQL statement:

SQL> SELECT name FROM v$parameter
         WHERE isdeprecated = 'TRUE';

A deprecated parameter behaves the same way as a regular parameter, except that a warning message is displayed at instance startup if a deprecated parameter is specified in the parameter file. In addition, all deprecated parameters are logged to the alert log at instance startup:


LOGMNR_MAX_PERSISTENT_SESSIONS
MAX_COMMIT_PROPAGATION_DELAY
REMOTE_ARCHIVE_ENABLE
SERIAL_REUSE
SQL_TRACE

Initialization Parameters Obsolete in Oracle Database 10g Release 2 (10.2)

The following initialization parameters were made obsolete in Oracle Database 10g Release 2 (10.2).

Note:

An attempt to start a database using one or more obsolete initialization parameters will succeed, but a warning is returned and recorded in the alert log.

ENQUEUE_RESOURCES

Static Data Dictionary Views with Dropped Columns in Oracle Database 10g Release 2 (10.2)

The following static data dictionary view columns were dropped in Oracle Database 10g Release 2 (10.2):

Static Data Dictionary View Dropped Columns
DBA_HIST_SQLBIND CHILD_NUMBER

SQL

The behavior of date formats has changed when used with XML functions. The XML Schema standard specifies that dates and timestamps in XML data be in standard formats. Prior to Oracle Database 10g Release 2 (10.2), dates and timestamps in XML data did not follow this standard; rather, the format of dates and timestamps in generated XML was determined by the database format.

As of Oracle Database 10g Release 2 (10.2), the XML generation functions in Oracle XML DB produce dates and timestamps according to the XML schema standard.

See Also:

Oracle XML DB Developer's Guide for more information

CONNECT Role

After upgrading from a release prior to Oracle Database 10g Release 2 (10.2), the CONNECT role has only the CREATE SESSION privilege; the other privileges granted to the CONNECT role in earlier releases are revoked during the upgrade. For further information about this, see "Deprecated CONNECT Role".

Time Zone Files

The time zone files that are supplied with Oracle Database 10g Release 2 (10.2) have been updated from version 4 to version 8 to reflect changes in transition rules for some time zone regions. The changes might affect existing data of TIMESTAMP WITH TIME ZONE data type. For further information about this, see "TIMESTAMP WITH TIME ZONE Data Type".

New Limit for FAILED_LOGIN_ATTEMPTS

As of Oracle Database 10g Release 2 (10.2), the limit for FAILED_LOGIN_ATTEMPTS for the DEFAULT profile is 10. Prior to Oracle Database 10g Release 2 (10.2), the default was UNLIMITED.

Compatibility and Interoperability Issues in Oracle Database 10g Release 1 (10.1)

The following sections describe compatibility and interoperability issues introduced in Oracle Database 10g Release 1 (10.1). If you are upgrading to Oracle Database 11g Release 1 (11.1) from a release prior to Oracle Database 10g Release 1 (10.1), then see the following sections for information about actions you can take to prevent problems resulting from these issues:

Initialization Parameters Deprecated in Oracle Database 10g Release 1 (10.1)

The following initialization parameters were deprecated in Oracle Database 10g Release 1 (10.1) To get a list of all deprecated initialization parameters, issue the following SQL statement:

SQL> SELECT name FROM v$parameter
         WHERE isdeprecated = 'TRUE';

A deprecated parameter behaves the same way as a regular parameter, except that a warning message is displayed at instance startup if a deprecated parameter is specified in the parameter file. In addition, all deprecated parameters are logged to the alert log at instance startup:


BUFFER_POOL_KEEP (replaced by DB_KEEP_CACHE_SIZE)
BUFFER_POOL_RECYCLE (replaced by DB_RECYCLE_CACHE_SIZE)
GLOBAL_CONTEXT_POOL_SIZE
LOCK_NAME_SPACE
LOG_ARCHIVE_START
MAX_ENABLED_ROLES
PARALLEL_AUTOMATIC_TUNING
PLSQL_COMPILER_FLAGS (replaced by PLSQL_CODE_TYPE and PLSQL_DEBUG)
SQL_VERSION

Initialization Parameters Obsolete in Oracle Database 10g Release 1 (10.1)

The following initialization parameters were made obsolete in Oracle Database 10g Release 1 (10.1).

Note:

An attempt to start a database using one or more obsolete initialization parameters will succeed, but a warning is returned and recorded in the alert log.

DBLINK_ENCRYPT_LOGIN
HASH_JOIN_ENABLED
LOG_PARALLELISM
MAX_ROLLBACK_SEGMENTS
MTS_CIRCUITS
MTS_DISPATCHERS
MTS_LISTENER_ADDRESS
MTS_MAX_DISPATCHERS
MTS_MAX_SERVERS
MTS_MULTIPLE_LISTENERS
MTS_SERVERS
MTS_SERVICE
MTS_SESSIONS
OPTIMIZER_MAX_PERMUTATIONS
ORACLE_TRACE_COLLECTION_NAME
ORACLE_TRACE_COLLECTION_PATH
ORACLE_TRACE_COLLECTION_SIZE
ORACLE_TRACE_ENABLE
ORACLE_TRACE_FACILITY_NAME
ORACLE_TRACE_FACILITY_PATH
PARTITION_VIEW_ENABLED
PLSQL_NATIVE_C_COMPILER
PLSQL_NATIVE_LINKER
PLSQL_NATIVE_MAKE_FILE_NAME
PLSQL_NATIVE_MAKE_UTILITY
ROW_LOCKING
SERIALIZABLE
TRANSACTION_AUDITING
UNDO_SUPPRESS_ERRORS

Static Data Dictionary Views Deprecated in Oracle Database 10g Release 1 (10.1)

The following static data dictionary views were deprecated in Oracle Database 10g Release 1 (10.1).


ALL_STORED_SETTINGS (replaced by ALL_PLSQL_OBJECT_SETTINGS)
DBA_STORED_SETTINGS (replaced by DBA_PLSQL_OBJECT_SETTINGS)
USER_STORED_SETTINGS (replaced by USER_PLSQL_OBJECT_SETTINGS)

Static Data Dictionary Views Obsolete in Oracle Database 10g Release 1 (10.1)

The following static data dictionary views were made obsolete in Oracle Database 10g Release 1 (10.1).

ALL_ Views DBA_ Views USER_ Views
ALL_SOURCE_TAB_COLUMNS DBA_SOURCE_TAB_COLUMNS USER_SOURCE_TAB_COLUMNS

Dynamic Performance Views Deprecated in Oracle Database 10g Release 1 (10.1)

The following dynamic performance views were deprecated in Oracle Database 10g Release 1 (10.1):


GV$CACHE
GV$CACHE_TRANSFER
GV$CLASS_CACHE_TRANSFER (replaced by GV$INSTANCE_CACHE_TRANSFER)
GV$FALSE_PING
GV$FILE_CACHE_TRANSFER (replaced by GV$INSTANCE_CACHE_TRANSFER)
GV$GC_ELEMENTS_WITH_COLLISIONS
GV$LOCK_ACTIVITY
GV$TEMP_CACHE_TRANSFER (replaced by GV$INSTANCE_CACHE_TRANSFER)
V$CACHE
V$CACHE_LOCK
V$CACHE_TRANSFER
V$CLASS_CACHE_TRANSFER (replaced by V$INSTANCE_CACHE_TRANSFER)
V$FALSE_PING
V$FILE_CACHE_TRANSFER (replaced by V$INSTANCE_CACHE_TRANSFER)
V$GC_ELEMENTS_WITH_COLLISIONS
V$LOCK_ACTIVITY
V$TEMP_CACHE_TRANSFER (replaced by V$INSTANCE_CACHE_TRANSFER)

Dynamic Performance Views Obsolete in Oracle Database 10g Release 1 (10.1)

The following dynamic performance views were made obsolete in Oracle Database 10g Release 1 (10.1):

GV$ Views V$ Views
GV$COMPATIBILITY V$COMPATIBILITY
GV$COMPATSEG V$COMPATSEG
GV$MLS_PARAMETERS V$MLS_PARAMETERS
GV$MTS V$MTS

SQL Optimizer

This section describes compatibility and interoperability issues relating to the SQL Optimizer in Oracle Database 10g Release 1 (10.1).

Rule-Based Optimizer Desupported

Starting with Oracle Database 10g Release 1 (10.1), the cost-based optimizer (CBO) is now enabled by default. The rule-based optimizer is no longer supported in Oracle Database 10g Release 1 (10.1). As a result, rule and choose are no longer supported as OPTIMIZER_MODE initialization parameter values and a warning is displayed in the alert log if OPTIMIZER_MODE is set to either of these values.

See Also:

Oracle Database Performance Tuning Guide for more information about the cost-based optimizer

Optimizer Statistics

Collection of optimizer statistics is now automatically performed by default for all schemas (including SYS), for pre-existing databases upgraded from a release prior to Oracle Database 10g Release 1 (10.1), and for newly created databases. Gathering optimizer statistics on stale objects is scheduled by default to occur daily during the maintenance window.

See Also:

Oracle Database Performance Tuning Guide for more information about optimizer statistics

COMPUTE STATISTICS Clause of CREATE INDEX

In earlier releases, the COMPUTE STATISTICS clause of CREATE INDEX could be used to start or stop the collection of statistics on an index. This clause has been deprecated. Oracle Database 10g Release 1 (10.1) and later releases automatically collect statistics during index creation and rebuild. This clause is supported for backward compatibility and does not cause errors.

SKIP_UNUSABLE_INDEXES

In earlier releases, SKIP_UNUSABLE_INDEXES was a session parameter only. In Oracle Database 10g Release 1 (10.1) and later releases, it is an initialization parameter and defaults to true. The true setting disables error reporting of indexes and index partitions marked UNUSABLE. This setting allows all operations (inserts, deletes, updates, and selects) on tables with unusable indexes or index partitions.

See Also:

SKIP_UNUSABLE_INDEXES in Oracle Database Reference

SQL Changes

Starting with Oracle Database 10g Release 1 (10.1), CLOB <-> NCLOB implicit conversion in SQL and PL/SQL is allowed.

Starting with Oracle Database 10g Release 1 (10.1), name resolution for synonyms has changed. If the base object of a synonym does not exist, then the SQL compiler now tries looking up PUBLIC.base_object.

Starting with Oracle Database 10g Release 1 (10.1), VPD policies are attached to synonyms rather than the base objects.

Invalid Synonyms After an Upgrade

Starting with Oracle Database 10g Release 1 (10.1), if a synonym (public or private) is pointing to an object that does not exist or is invalid, then the synonym is invalid after the upgrade.

Manageability

Database performance statistics are now automatically collected by the Automatic Workload Repository (AWR) database component for databases upgraded from a release prior to Oracle Database 10g Release 1 (10.1) and for newly created databases. This data is stored in the SYSAUX tablespace, and is used by the database for automatic generation of performance recommendations.

If you currently use Statspack for performance data gathering, then refer to the Statspack README (spdoc.txt, located in the ORACLE_HOME/rdbms/admin directory) for directions on using Statspack in Oracle Database 10g Release 1 (10.1) and later releases to avoid conflict with the AWR.

Transaction and Space

Starting with Oracle Database 10g Release 1 (10.1), dropped objects are now moved to the recycle bin where the space is only reused when it is needed. This allows an object to be undropped using the FLASHBACK DROP feature.

Starting with Oracle Database 10g Release 1 (10.1), automatic tuning of undo retention is enabled by default. The UNDO_SUPPRESS_ERRORS initialization parameter has been deprecated. Errors generated when executing rollback segment operations while in automatic undo management mode are always suppressed.

Starting with Oracle Database 10g Release 1 (10.1), the default AUTOEXTEND NEXT size is larger for Oracle managed files (OMF).

Recovery and Data Guard

Starting with Oracle Database 10g Release 1 (10.1), the LOG_ARCHIVE_START initialization parameter has been deprecated. Archiving is now automatically started when the database is placed in ARCHIVELOG mode.

Starting with Oracle Database 10g Release 1 (10.1), the LOG_PARALLELISM initialization parameter has been deprecated. Log file parallelism is now automatically enabled.

Starting with Oracle Database 10g Release 1 (10.1), the default value for the RECOVERY_PARALLELISM initialization parameter now defaults to allow parallel recovery.

Starting with Oracle Database 10g Release 1 (10.1), the default value for the parallel clause in the ALTER DATABASE RECOVER DATABASE statement has changed to PARALLEL.

Starting with Oracle Database 10g Release 1 (10.1), the default buffer size for the ASYNC attribute of the LOG_ARCHIVE_DEST_n initialization parameter has increased from 2,048 blocks to 61,440 blocks.

Starting with Oracle Database 10g Release 1 (10.1), the default values of the parameters MAX_SGA and MAX_SERVERS as set by the DBMS_LOGSTDBY.APPLY_SET() procedure have changed.

Starting with Oracle Database 10g Release 1 (10.1), the default values for the Data Guard broker properties ApplyParallel, AsyncBlocks, and LogXptMode have changed.

Starting with Oracle Database 10g Release 1 (10.1), the default behavior of the STARTUP SQL*Plus command and the ALTER DATABASE MOUNT and ALTER DATABASE OPEN SQL statements have changed for physical standby databases. The commands now automatically detect that the database is a physical standby and thus the STANDBY DATABASE and READ ONLY options are made default.

RMAN

Starting with Oracle Database 10g Release 1 (10.1), RMAN now creates an empty file when restoring a file from backup and no backup of the file exists. RMAN backup of archived logs now automatically backs up logs that were created before the last resetlogs. Such logs were previously ignored.

Starting with Oracle Database 10g Release 1 (10.1), RMAN now continues to run the remaining portions of a backup or restore job when it encounters an error. RMAN now tries to restore from an alternate backup if it finds the targeted backup is corrupt.

CREATE DATABASE

In Oracle Database 10g Release 1 (10.1) and later releases, a SYSAUX tablespace is always created at database creation time or whenever a database is upgraded. The SYSAUX tablespace serves as an auxiliary tablespace to the SYSTEM tablespace. Because SYSAUX is the default tablespace for many Oracle features and products that previously required their own tablespaces, it reduces the number of tablespaces that a DBA must maintain.

See Also:

Oracle Database Administrator's Guide for more information about the SYSAUX tablespace

Starting with Oracle Database 10g Release 1 (10.1), the minimum and default log file sizes have increased. The minimum size is now 4 MB. The default size is 50 MB, unless using Oracle managed files (OMF) in which case the default is 100 MB.

Oracle Real Application Clusters

In Oracle Database 10g Release 1 (10.1), there is an automated high availability (HA) framework for Oracle Real Application Clusters. The framework provides detection, recovery, restart, and notification services.

Materialized Views

Starting with Oracle Database 10g Release 1 (10.1), some privilege name changes have been made. The new names appear in all data dictionary views, but both the old and new names are accepted by the GRANT and REVOKE SQL statements.

  • CREATE SNAPSHOT changed to CREATE MATERIALIZED VIEW

  • CREATE ANY SNAPSHOT changed to CREATE ANY MATERIALIZED VIEW

  • ALTER ANY SNAPSHOT changed to ALTER ANY MATERIALIZED VIEW

  • DROP ANY SNAPSHOT changed to DROP ANY MATERIALIZED VIEW

Change Data Capture

Starting with Oracle Database 10g Release 1 (10.1), the interfaces in DBMS_CDC_SUBSCRIBE and DBMS_CDC_PUBLISH now take a subscription name parameter instead of a subscription handle.

Starting with Oracle Database 10g Release 1 (10.1), subscriber views are now managed automatically. There is no longer any requirement to call the DBMS_CDC_SUBSCRIBE and DBMS_CDC_PUBLISH interfaces PREPARE_SUBSCRIBER_VIEW() and DROP_SUBSCRIBER_VIEW().

Starting with Oracle Database 10g Release 1 (10.1), the computation of synchronous Change Data Capture's RSID$ column has been changed to facilitate joining a subscriber view to itself in order to show both old and new values in the same row. The RSID$ values for the UO and UN rows associated with the same update operation are now the same. To revert to the Oracle9i behavior where UN RSID$ value is UO RSID$ value + 1 for the same update operation, set event 10983 to level 4.

Change in the Default Archival Processing to Remote Archive Destinations

Starting with Oracle Database 10g Release 1 (10.1), the default archival processing to remote destinations has changed so that archiver processes on the primary database completely and successfully archive the local online redo log files before transmitting the redo data to remote standby destinations. This default behavior is equivalent to setting the LOG_ARCHIVE_LOCAL_FIRST initialization parameter to true, which is also new in Oracle Database 10g Release 1 (10.1) and later releases. Note that this new default archival processing is relevant only when log transport services are defined to use archiver processes (ARCn), not the log writer process (LGWR), when the archiver processes are writing to remote destinations, and when the remote standby destination is not a mandatory destination.

Prior to Oracle Database 10g Release 1 (10.1), the default behavior was to transmit redo data to the standby destination at the same time the online redo log file was being archived to the local online redo log files. You can achieve this behavior by setting the LOG_ARCHIVE_LOCAL_FIRST initialization parameter to false. This archival processing is also relevant only when log transport services are defined to use archiver processes (ARCn), not the log writer process (LGWR), when the archiver processes are writing to remote destinations, and when the remote standby destination is not a mandatory destination.

The benefit of the new default behavior is that local archiving, and hence, processing on the primary database, are not affected by archival to non-mandatory, remote destinations. Because local archiving is now disassociated with remote archiving, sites that might have policies to delete archived redo log files on the primary database immediately after backing them up must make sure that the standby destinations have received the corresponding redo data before deleting the archived redo log files on the primary database. You can query the V$ARCHIVED_LOG view to verify that the redo data has been received on standby destinations.

Note:

Any value specified for the LOG_ARCHIVE_LOCAL_FIRST initialization parameter is ignored for mandatory destinations (configured with the MANDATORY attribute of the LOG_ARCHIVE_DEST_n initialization parameters).

See Also:

Oracle Data Guard Concepts and Administration for complete information about setting up archival to remote destinations

Limitations on NCHAR Data Types

Starting with Oracle9i, the NCHAR data types such as NCHAR, NVARCHAR2, and NCLOB, are limited to the Unicode character set encoding, UTF8 and AL16UTF16.

PL/SQL Native Compilation

Starting with Oracle Database 10g Release 1 (10.1), the configuration of initialization parameters and the command setup for native compilation has been simplified. The important parameters now are PLSQL_NATIVE_LIBRARY_DIR and PLSQL_NATIVE_LIBRARY_SUBDIR_COUNT. The parameters related to the compiler, linker, and make utility have been made obsolete. Native compilation is turned on and off by a separate initialization parameter, PLSQL_CODE_TYPE, rather than being one of several options in the PLSQL_COMPILER_FLAGS parameter, which is now deprecated. The spnc_commands file, located in the ORACLE_HOME/plsql directory, contains the commands and options for compiling and linking, rather than a makefile.

See Also:

Evaluation of Numeric Literals

Evaluation of numeric literals has changed such that at least one of the constants in a numeric computation with literals must be a decimal specified to the 10th place. This is because releases after Oracle Database 10g Release 1 (10.1) use INTEGER arithmetic (approximately 9 significant digits) for some expressions whereas Oracle9i Release 2 (9.2) used NUMBER arithmetic (approximately 38 significant digits).

Therefore, if you are dealing with results of greater than 9 significant digits, then one of the literals should be in decimal format to prevent numeric overflow errors. For example, in Oracle Database 10g Release 1 (10.1), the computation of v1 in the following example causes a numeric overflow error:

DECLARE
  v1 NUMBER(38);
BEGIN
  v1 := 256*256*256*256;
  DBMS_OUTPUT.PUT_LINE(v1);
END;
/

The solution to the error is to specify one of the numeric literals as a decimal (256.0), as follows:

DECLARE
  v1 NUMBER(38);
BEGIN
  v1 := 256*256*256*256.0;
  DBMS_OUTPUT.PUT_LINE(v1);
END;
/

See Also:

Change in Behavior for SESSION_CACHED_CURSORS

Starting with Oracle Database 10g Release 1 (10.1), the number of cached cursors is determined by the SESSION_CACHED_CURSORS initialization parameter. In previous Oracle Database releases, the number of SQL cursors cached by PL/SQL was determined by the OPEN_CURSORS initialization parameter.

See Also:

SESSION_CACHED_CURSORS in Oracle Database Reference

New Default Value for DB_BLOCK_SIZE

Starting with Oracle Database 10g Release 1 (10.1), the default value of DB_BLOCK_SIZE is operating system specific, but is typically 8 KB (8192 bytes). In previous Oracle Database releases, the default value was 2 KB (2048 bytes). If DB_BLOCK_SIZE is not specified in the parameter file when upgrading from Oracle9i Release 2 (9.2), then you receive an error when attempting to start up your database. Add the following to your parameter file:

DB_BLOCK_SIZE = 2048

If DB_BLOCK_SIZE is specified in the parameter file, then Oracle Database uses this value instead of the default value of 8 KB.

OPTIMIZER_MAX_PERMUTATIONS and OPTIMIZER_FEATURES_ENABLE

Starting with Oracle Database 10g, the OPTIMIZER_MAX_PERMUTATIONS initialization parameter has been made obsolete. If you are upgrading from Oracle9i and have OPTIMIZER_FEATURES_ENABLE set to 8.1.7 or earlier and OPTIMIZER_MAX_PERMUTATIONS explicitly set to 2000 in the parameter file, then the release 8.1.7 default of 80000 is used when you start up the Oracle Database 11g Release 1 (11.1) database.

Setting OPTIMIZER_FEATURES_ENABLE to 9.0.0 or higher sets the default to 2000

Change in Behavior for LOG_ARCHIVE_FORMAT

Starting with Oracle Database 10g Release 1 (10.1), if the COMPATIBLE initialization parameter is set to 10.0.0 or higher, then archive log file names must contain each of the elements %s (sequence), %t (thread), and %r (resetlogs ID) to ensure that all archive log file names are unique. If the LOG_ARCHIVE_FORMAT initialization parameter is set in the parameter file, then make sure the parameter value contains the %s, %t, and %r elements.

New Default Value for PGA_AGGREGATE_TARGET

Starting with Oracle Database 10g Release 1 (10.1), Automatic PGA Memory Management is now enabled by default (unless PGA_AGGREGATE_TARGET is explicitly set to 0 or WORKAREA_SIZE_POLICY is explicitly set to MANUAL). PGA_AGGREGATE_TARGET defaults to 20% of the size of the SGA, unless explicitly set. Oracle recommends tuning the value of PGA_AGGREGATE_TARGET after upgrading.

Change in Behavior for SHARED_POOL_SIZE

In previous releases, the amount of shared pool memory that was allocated was equal to the value of the SHARED_POOL_SIZE initialization parameter plus the amount of internal SGA overhead computed during instance startup. Starting with Oracle Database 10g Release 1 (10.1), the value of SHARED_POOL_SIZE must now also accommodate this shared pool overhead.

Since Oracle Database release 9.2, the shared pool can be partitioned into multiple parts. The partitions are called shared pool subpools and there can be up to seven subpools. Although there is no standard recommendation, you should configure the shared pool memory in a way that generates larger subpools than the default size. For example, 256M and 500M seem to work better as subpool sizes for Oracle Database releases 9i and 10g, respectively. Having adequate sizes allocated for shared pool subpools can avoid raising ORA-4031 errors.

Shared Server Parameters

Starting with Oracle Database 10g Release 1 (10.1), the recommended way to turn on shared server mode is to set SHARED_SERVERS to a value greater than 0. This can be done at startup or dynamically after the instance is started. If shared server mode is turned off by setting SHARED_SERVERS to 0, then this only affects new clients (that is, no new clients can connect in shared mode; clients that are already connected in shared mode continue to be serviced by shared servers).

In previous releases, the recommended way to turn on shared server mode was to set DISPATCHERS. If SHARED_SERVERS was changed to 0 and shared server clients were still connected, then client requests would hang.

Prior to Oracle Database 10g Release 1 (10.1), the following shared server parameters could not be changed dynamically:

  • MAX_SHARED_SERVERS

  • MAX_DISPATCHERS

  • SHARED_SERVER_SESSIONS

  • CIRCUITS

Starting with Oracle Database 10g Release 1 (10.1), these shared server parameters are dynamically modifiable.

New Default Value for DISPATCHERS

Starting with Oracle Database 10g Release 1 (10.1), the default for DISPATCHERS is '(PROTOCOL=TCP)'. DISPATCHERS is given this default value if it is not set or if it is set to '' and SHARED_SERVERS is set to 1 or higher.

In previous releases, there was no default value for DISPATCHERS.

New Default Value for SHARED_SERVERS

Starting with Oracle Database 10g Release 1 (10.1), if DISPATCHERS is set such that the total number of dispatchers is equal to 0, then SHARED_SERVERS defaults to 0. If DISPATCHERS is set such that the total number of dispatchers is greater than 0, then SHARED_SERVERS defaults to 1 as in previous releases.

In previous releases, if DISPATCHERS was set such that the number of dispatchers is equal to 0, then SHARED_SERVERS defaulted to 1.

New Default Value for MAX_SHARED_SERVERS

Starting with Oracle Database 10g Release 1 (10.1), there is no preset default for MAX_SHARED_SERVERS. The maximum number of shared servers varies depending on the number of free process slots. If MAX_SHARED_SERVERS is not set or is set to a value greater than or equal to PROCESSES, then PMON does not spawn any more shared servers if the number of free process slots is either 2 (if PROCESSES is less than 24) or is less than 1 / 8, unless the existing servers are involved in a deadlock situation. If the existing servers are involved in a deadlock situation, then no matter the transaction load, a new server is spawned if there is a free process slot.

In previous releases, the default for MAX_SHARED_SERVERS is 20, or 2 * SHARED_SERVERS, whichever is greater, subject to the condition that MAX_SHARED_SERVERS does not exceed PROCESSES.

Starting with Oracle Database 10g Release 1 (10.1), SHARED_SERVERS can be set higher than MAX_SHARED_SERVERS, in which case the number of servers remains constant at the level set for SHARED_SERVERS. This is to allow the range SHARED_SERVERS - MAX_SHARED_SERVERS to be changed without having to change these parameters in a specific order.

In previous releases, SHARED_SERVERS cannot be set higher than MAX_SHARED_SERVERS.

New Default Value for SHARED_SERVER_SESSIONS

Starting with Oracle Database 10g Release 1 (10.1), there is no preset default for SHARED_SERVER_SESSIONS. That is, if SHARED_SERVER_SESSIONS is not specified, then shared server sessions can be created as needed and as permitted by the session limit.

In previous releases, the default for SHARED_SERVER_SESSIONS was the maximum number of virtual circuits (CIRCUITS), or the maximum number of database sessions (SESSIONS) - 5, whichever is smaller.

New Default Value for CIRCUITS

Starting with Oracle Database 10g Release 1 (10.1), there is no preset default for CIRCUITS. That is, if CIRCUITS is not specified, then circuits can be created as needed and as permitted by dispatcher constraints and system resources.

In previous releases, the default for CIRCUITS was the maximum number of database sessions (SESSIONS) if shared server mode was enabled, 0 otherwise.

New Default Value for MAX_DISPATCHERS

Starting with Oracle Database 10g Release 1 (10.1), there is no preset default for MAX_DISPATCHERS. MAX_DISPATCHERS no longer limits the number of dispatchers; the user can increase the number of dispatchers with the DISPATCHERS parameter as long as there are free process slots and system resources.

In previous releases, the default for MAX_DISPATCHERS was 5, or the total number of dispatchers specified with the DISPATCHERS parameter, whichever was greater.