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Oracle Tips by Burleson

A Detailed Look at ARCHIVE LOG Clauses

For Oracle8 much of the ARCHIVE LOG command is removed from SVRMGR (except for the pull-down display) and is placed under the ALTER SYSTEM command (shown above). The new command has additional clauses to handle the more complex archive log scheme under Oracle8, Oracle8i and Oracle9i. The new syntax handles the threads and groups associated with the new archive logs. The new syntax follows:

See Code Depot

where:

THREAD. This specifies the particular redo log thread to affect. If this isn’t specified then the current instance redo log thread is affected.

SEQUENCE. This archives the redo log group that corresponds to the integer specified by the integer given as the argument.

CHANGE. This corresponds to the SCN (system change number) for the transaction you want to archive. It will force archival of the log containing the transaction with the SCN that matches the integer given as the argument to the CHANGE argument.

GROUP. This manually archives the redo logs in the specified group. If both THREAD and GROUP are specified, the group must belong to the specified thread.

CURRENT. This causes all nonarchived redo log members of the current group to be archived.

LOGFILE. This manually archives the group that contains the file specified by ‘filespec’. If thread is specified the file must be in a group contained in the thread specified.

NEXT. This forces manual archival of the next on-line redo log that requires it. If no thread is specified, Oracle archives the earliest available unarchived redo log.

ALL. This archives all on-line archive logs that are part of the current thread that haven’t been archived. If no thread is specified then all unarchived logs from all threads are archived.

START. Starts automatic archiving of redo log file groups. This only applies to the thread assigned to the current instance.

TO. This specifies the location to archive the logs to. This must be a full path specification.

STOP. This disables automatic archiving of redo file log groups. This applies to your current instance.

The ARCHIVE LOG command can still be used under SVRMGR in Oracle versions that support it to LIST the current status of the archive log system.

2.5 The Init<sid>.Ora (Initialization File) Parameters

It should be obvious that the most important file regarding database setup and operation is probably the INIT<sid>.ORA, or initialization file. This file contains the assignments for the database initialization parameters.

For Oracle7, version 7.3, there are 154 initialization parameters; for Oracle8, version 8.0.5, there are 184. In Oracle8i, there are 194. In Oracle9i, version 9.0.1 there are 251. Table 2.1 lists the Oracle9i INIT.ORA parameters, their default values, and descriptions. Note that on your platform there may be more or less than this number of parameters.