Initialization Parameter Changes in Oracle Database 12c Release 2 (12.2)

Review to see the list of new, deprecated, and desupported initialization parameters in this release.

Deprecated Initialization Parameters in Oracle Database 12c Release 2 (12.2)

Review the deprecated initialization parameters in this release to understand changes and replacements in parameter settings.

O7_DICTIONARY_ACCESSIBILITY Initialization parameter

The initialization parameter O7_DICTIONARY_ACCESSIBILITY controls restrictions on SYSTEM privileges. If the parameter is set to TRUE, then access to objects in the SYS schema is allowed. The default setting is FALSE. This default setting prevents system privileges that allow access to objects in any schema from allowing access to objects in the SYS schema. The O7_DICTIONARY_ACCESSIBILITY parameter is deprecated.

ASM_PREFERRED_READ_FAILURE_GROUPS Initialization Parameter

The ASM_PREFERRED_READ_FAILURE_GROUPS initialization parameter is deprecated in Oracle Automatic Storage Management 12c release 2 (12.2.0.1). Starting with Oracle Automatic Storage Management (Oracle ASM) 12c release 2 (12.2.0.1), specifying the preferred read failure groups is done automatically, so the use of the ASM_PREFERRED_READ_FAILURE_GROUPS initialization parameter is no longer required. Use the PREFERRED_READ.ENABLED disk group attribute to control the preferred read functionality.

PARALLEL_ADAPTIVE_MULTI_USER Initialization Parameter

The initialization parameter PARALLEL_ADAPTIVE_MULTI_USER specifies if you want to use an adaptive algorithm to improve performance in multi-user environments that use parallel execution. This parameter is deprecated, and the default value is now FALSE. There is no replacement for this parameter. Oracle recommends that you use the Oracle Database feature Parallel Statement Queuing to obtain parallel execution performance gains.

UTL_FILE_DIR Initialization Parameter

The initialization parameter UTL_FILE_DIR specifies accessible directories for PL/SQL file I/O. This parameter is deprecated, and Oracle recommends that you do not provide UTL_FILE_DIR access. Oracle recommends that you instead use the directory object feature, which replaces UTL_FILE_DIR. Directory objects provide the following benefits:

  • They offer more flexibility and granular control to the UTL_FILE application administrator

  • They can be maintained dynamically, without shutting down the database

  • They are consistent with other Oracle tools.

Desupported Initialization Parameters in Oracle Database 12c Release 2 (12.2)

Review this list of desupported initialization parameters for changes and replacements in parameter settings in this release.

GLOBAL_CONTEXT_POOL_SIZE Initialization Parameter

The GLOBAL_CONTEXT_POOL_SIZE initialization parameter is removed and desupported in this release.

GLOBAL_CONTEXT_POOL_SIZE specified the amount of memory to allocate in the SGA for storing and managing global application context. The default value of this parameter was null. The parameter was deprecated in Oracle Database 10g release 2 (10.2).

MAX_ENABLED_ROLES Initialization Parameter

The MAX_ENABLED_ROLES initialization parameter is removed and desupported in this release.

There is no replacement for this parameter. Oracle Database has not used this parameter since Oracle Database 10g release 2 (10.2).

OPTIMIZER_ADAPTIVE_FEATURES Initialization Parameter

The OPTIMIZER_ADAPTIVE_FEATURES initialization parameter is removed and desupported in this release.

The functions of this parameter are replaced by two new parameters. The default value for OPTIMIZER_ADAPTIVE_PLANS is TRUE. When set to TRUE, this parameter determines alternate execution plans that are based on statistics collected as a query executes. OPTIMIZER_ADAPTIVE_STATISTICS is set by default to FALSE. When set to TRUE, the optimizer augments the statistics gathered in the database with adaptive statistics gathered at SQL statement parse time to improve the quality of SQL execution plans.

PARALLEL_AUTOMATIC_TUNING Initialization Parameter

The PARALLEL_AUTOMATIC_TUNING initialization parameter is removed and desupported in this release.

The PARALLEL_AUTOMATIC_TUNING initialization parameter determined the default values for parameters that controlled parallel processing. It was deprecated in Oracle Database 10g release 2 (10.2).

PARALLEL_IO_CAP_ENABLED Initialization Parameter

The PARALLEL_IO_CAP_ENABLED initialization parameter determined if Oracle Database set a limit to the default degree of parallelism to a level no greater than the I/O system supported. This parameter was deprecated in Oracle Database release 11.2. The function of this parameter was replaced by the PARALLEL_DEGREE_LIMIT parameter, when that parameter is set to IO.

PARALLEL_SERVER Initialization Parameter

The PARALLEL_SERVER initialization parameter is removed and desupported in this release.

The PARALLEL_SERVER initialization parameter was used to start a database in Oracle Parallel Server mode. This parameter was deprecated in Oracle Database release 9.0.1. Oracle Parallel Server was replaced with Oracle Real Application Clusters, which uses the CLUSTER_DATABASE initialization parameter.

PARALLEL_SERVER_INSTANCES Initialization Parameter

The PARALLEL_SERVER_INSTANCES initialization parameter is removed and desupported in this release.

The PARALLEL_SERVER_INSTANCES initialization parameter specified the number of configured instances in Oracle Parallel Server mode. This parameter was deprecated in Oracle Database release 9.0.1. Oracle Parallel Server was replaced with Oracle Real Application Clusters, which uses the CLUSTER_DATABASE_INSTANCES initialization parameter.

USE_INDIRECT_DATA_BUFFERS Initialization Parameter

The initialization parameter USE_INDIRECT_DATA_BUFFERS is removed and desupported in this release.

The parameter was used to enable the Very Large Memory feature for 32-bit platforms. These platforms are no longer supported.

Initialization Parameter Default Changes in Oracle Database 12c Release 2 (12.2)

Review this list of initialization parameter default setting changes for Oracle Database 12c release 2 (12.2).

OPTIMIZER_ADAPTIVE_PLANS and OPTIMIZER_ADAPTIVE_STATISTICS

OPTIMIZER_ADAPTIVE_FEATURE functions are replaced by two new parameters: OPTIMIZER_ADAPTIVE_PLANS, and OPTIMIZER_ADAPTIVE_STATISTICS.

OPTIMIZER_ADAPTIVE_PLANS controls adaptive plans. It is set by default to TRUE. When set to TRUE, this parameter determines alternate execution plans built with alternative choices that are based on statistics collected as a query executes.

OPTIMIZER_ADAPTIVE_STATISTICS controls adaptive statistics. It is set by default to FALSE. When set to TRUE, the optimizer augments the statistics gathered in the database with adaptive statistics gathered at SQL statement parse time to improve the quality of SQL execution plans. Some query shapes are too complex to rely upon base table statistics alone. The optimizer augments them with adaptive statistics to determine more accurately the best SQL execution plan.

SQL92_SECURITY Initialization Parameter Default is TRUE

The SQL standard specifies that security administrators should be able to require that users have SELECT privilege on a table when running an UPDATE or DELETE statement that references table column values in a WHERE or SET clause. SQL92_SECURITY specifies whether users must have been granted the SELECT object privilege in order to execute such UPDATE or DELETE statements.

Starting in Oracle Database 12c release 2 (12.2), the default setting for this parameter changes from FALSE to TRUE.

When this parameter is set to TRUE, users must have SELECT privilege on the object being deleted or updated.