LOG_ARCHIVE_FORMAT

Property	Description
Parameter type	String
Syntax	LOG_ARCHIVE_FORMAT = filename
Default value	Operating system-dependent
Modifiable	No
Range of values	Any string that resolves to a valid filename
Basic	No
Real Application Clusters	Multiple instances can have different values, but identical values are recommended.

LOG_ARCHIVE_FORMAT is applicable only if you are using the redo log in ARCHIVELOG mode. Use a text string and variables to specify the default filename format when archiving redo log files. The string generated from this format is appended to the string specified in the LOG_ARCHIVE_DEST parameter.

The following variables can be used in the format:

%s: log sequence number

%S: log sequence number, zero filled

%t: thread number

%T: thread number, zero filled

%a: activation ID

%d: database ID

%r: resetlogs ID that ensures unique names are constructed for the archived log files across multiple incarnations of the database

Using uppercase letters for the variables (for example, %S) causes the value to be fixed length and padded to the left with zeros. An example of specifying the archive redo log filename format follows:

LOG_ARCHIVE_FORMAT = 'log%t_%s_%r.arc'

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. Otherwise, the following error is displayed at the time of instance startup:

ORA-19905: log_archive_format must contain %s, %t and %r

Neither LOG_ARCHIVE_DEST nor LOG_ARCHIVE_FORMAT have to be complete file or directory specifiers themselves; they only need to form a valid file path after the variables are substituted into LOG_ARCHIVE_FORMAT and the two parameters are concatenated together.

Note:

1. Query for the current value of the parameter

select name, value, isdefault, isses_modifiable, issys_modifiable,

isinstance_modifiable, isdeprecated, description

from v$parameter

where upper(name) = ‘LOG_ARCHIVE_FORMAT’;

NAME	VALUE	IS DEFAULT	ISSES_ MODIFIABLE	ISSYS_ MODIFIABLE	ISINSTANCE_ MODIFIABLE	IS DEPRECATED	DESCRIPTION
log_archive_format	idwprod1_%s%t%r.dbf	FALSE	FALSE	FALSE	FALSE	FALSE	archival destination format

Oracle initializatoin parameters