Initialization Parameter Changes in Oracle Database 18c

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

• STANDBY_ARCHIVE_DEST is Desupported
  Support for the initialization parameter STANDBY_ARCHIVE_DEST is removed in Oracle Database 18c.
• UNIFORM_LOG_TIMESTAMP_FORMAT Changes in INIT.ORA
  By default, the format of timestamps is different in Oracle Database 12c release 2 (12.2) and later releases. To view alert logs, use the Oracle Database utility Automatic Diagnostic Repository Command Interpreter (ADRCI) utility.
• Desupport of UTL_FILE_DIR Initialization Parameter
  Starting in Oracle Database 18c, the UTL_FILE_DIR parameter is no longer supported. Instead, specify the name of a directory object.

STANDBY_ARCHIVE_DEST is Desupported

Support for the initialization parameter STANDBY_ARCHIVE_DEST is removed in Oracle Database 18c.

Oracle Database 11g Release 2 (11.2) included an increase to 31 of the parameters LOCAL and REMOTE archiving LOG_ARCHIVE_DEST_n. This increase, and the ALTERNATE attribute enhancements to provide high availability for local and remote archiving, provides you with more control over the results after an archiving destination fails. Because of these enhancements, STANDBY_ARCHIVE_DEST is not required or practical to use.

UNIFORM_LOG_TIMESTAMP_FORMAT Changes in INIT.ORA

By default, the format of timestamps is different in Oracle Database 12c release 2 (12.2) and later releases. To view alert logs, use the Oracle Database utility Automatic Diagnostic Repository Command Interpreter (ADRCI) utility.

If you use scripts to parse the alert log for timestamp dates, then be aware that the default value for timestamp formats is set by the init.ora parameter UNIFORM_LOG_TIMESTAMP_FORMAT. The default value for this parameter is TRUE. When TRUE, the timestamp format changes from a day-month-year-time format to a year-month-day-time format. For example: 2017-05-17T10:00:54.799968+00:00.

You can change to the timestamp format used in previous releases by changing the value of UNIFORM_LOG_TIMESTAMP_FORMAT to FALSE. You can also use scripts to parse log.xml instead of the alert log.

Oracle provides a dedicated command-line utility to find and analyze Oracle errors and tracefiles, called Automatic Diagnostic Repository Command Interpreter (ADRCI) Oracle recommends that you use the ADRCI utility for error management.

For example, you can use the ADRCI command show alert to view the alert log:

$ oracle@user> adrci
adrci> show alert -tail -f

ADRCI also enables you to use the show log command to pass predicates for a query. For example:

adrci> show log -p "message_text like '%tablespace%'"

Refer to Oracle Database Utilities for more information about how to use the ADRCI utility.

Desupport of UTL_FILE_DIR Initialization Parameter

Starting in Oracle Database 18c, the UTL_FILE_DIR parameter is no longer supported. Instead, specify the name of a directory object.

The UTL_FILE_DIR initialization parameter is no longer listed in V$SYSTEM_PARAMETER and related views. If you attempt to set this parameter, then the attempt fails. If you attempt to specify an operating system file directly by using the LOCATION parameter of UTL_FILE.FOPEN, or by using the LOCATION parameter of FOPEN_NCHAR, then those attempts also fail. Specify the name of a directory object instead.

The security model for the use of a directory object for UTL_FILE and other Oracle Database subsystems is secure, because there is a clear privilege model. However, the use of an explicit operating system directory is insecure, because there is no associated privilege model. The notice of deprecation for the UTL_FILE_DIR initialization parameter was given in Oracle Database 12c Release 2 (12.2). With Oracle Database 18c, the parameter is now desupported.

UTL_FILE Package Symbolic Link in Directory Paths Not Supported

Using the UTL_FILE package to access a symbolic link fails in the new Oracle Database release. To avoid the issue, you must change the directory object and the file name, so that neither contains a symbolic link. This desupport can affect any feature from an earlier release using symbolic links, including (but not restricted to) Oracle Data Pump, BFILEs, and External Tables. If you attempt to use an affected feature after upgrade, where that feature used symbolic links, you encounter ORA-29283: invalid file operation: path traverses a symlink.