New Database Initialization Parameters

Oracle Database 10g has introduced a large number of new initialization parameters, many of which have been covered in previous chapters. This section covers some of the interesting ones that have not yet been mentioned:

• DDL_WAIT_FOR_LOCKS specifies whether DDL statements such as ALTER TABLE ... ADD COLUMN wait and complete instead of timing out if the statement is not able to acquire all required locks. The default value is FALSE and hence DDL statements time out if the statement cannot obtain all required locks.

• LDAP_DIRECTORY_ACCESS specifies whether Oracle refers to the Oracle internet Directory (OiD) for user-authentication information. If directory access is turned on, then this parameter also specifies how users are authenticated. The default is NONE.

• LOG_ARCHIVE_LOCAL_FIRST specifies when the archiver processes (ARCn) transmit redo data to remote standby database destinations. The default value is trUE, which directs the ARCn process to transmit redo data after the online redo log file has been completely and successfully archived to at least one local destination. Because the online redo log files are archived locally first, the LGWR process reuses the online redo log files much earlier than would be possible if the ARCn processes archived to the standby database concurrently with the local destination. This behavior is useful when archiving to remote destinations that use a slow network connection, such as a long-distance wide area network (WAN).

• PLSQL_CODE_TYPE specifies the compilation mode for PL/SQL library units in order to support native compilation when set to NATIVE. The default value is INTERPRETED, which is the old method in order to keep applications from breaking unexpectedly. Native compilation will enable faster execution. The new PLSQL_OPTIMIZE_LEVEL parameter further defines the level used to compile these library units.

• PLSQL_DEBUG specifies whether or not PL/SQL library units will be compiled for debugging. The default value is FALSE. When PLSQL_DEBUG is set to trUE, PL/SQL library units are always compiled INTERPRETED in order to support debugging. Note that the PLSQL_COMPILER_FLAGS parameter has been deprecated in favor of this and the PLSQL_CODE_TYPE-parameters.

• PLSQL_WARNINGS enables or disables the reporting of warning messages by the PL/SQL compiler and specifies which warning messages to show as errors. The default value is DISABLE:ALL.

• RESUMABLE_TIMEOUT enables or disables resumable statements and specifies resumable timeout at the system level. The Oracle Database Administrator's Guide specifies how to enable resumable space allocation, what conditions are correctable, what statements can be made resumable, and so on. The default value is 0 seconds and can go up to 2³¹1.