Showing posts with label Archive. Show all posts
Showing posts with label Archive. Show all posts

Oracle Archive Log

What is oracle archive log?
Oracle stores the history of transaction that occur in the database in the archive log. It uses to recover a database, update a standby database and getting the history information of the database using a log miner utility.

All the archive log destination information can be found from this table: V$ARCHIVE_DEST


Understanding the archive destination
We can choose on how many location we want to store the archived redo log information. It can be a single location or multiple destination. For DR system, we can specify the second location as a method of delivery/shipment of the archived redo log.

For a single location, you can use the parameter LOG_ARCHIVE_DEST.

For multiple location, there are 2 method in doing this:

  • First method
    parameter: LOG_ARCHIVE_DEST_n
    -Where n can be any destination that you wanted. This can be local or remote host
  • Second method
    parameter: LOG_ARCHIVE_DEST , LOG_ARCHIVE_DUPLEX_DEST
    - This can be only on local host

LOG_ARCHIVE_DEST_n value
Two values that can set for the parameter:

  1. LOCATION
    - for local filesystem
    - e.g. : LOG_ARCHIVE_DEST_1 = 'LOCATION=/disk1/arc'
  2. SERVICE
    - Remote archival through Oracle Net service name. This is based on tnsnames.ora file set in ORACLE_HOME/920/Network/admin folder.
    - e.g. : 'SERVICE=standby1'

Archive DEFINITION

DEFINITION - 1) An archive is a collection of computer files that have been packaged together for backup, to transport to some other location, for saving away from the computer so that more hard disk storage can be made available, or for some other purpose. An archive can include a simple list of files or files organized under a directory or catalog structure (depending on how a particular program supports archiving).

On personal computers with the Windows operating system, WinZip is a popular program that lets you create an archive (a single file that holds a number of files that you plan to save to another medium or send someone electronically) or extract its files. WinZip also compresses the files that are archived, but compression is not required to create an archive. A WinZip archive has the file name suffix ".zip".

In Unix-based operating systems, the tar (tape archive) utility can be used to create an archive or extract files from one. On mainframe operating systems such as IBM's MVS and OS/390, procedures for archiving or backing up files are often automated as a daily operation.

2) On Web sites as well as in libraries, an archive is a collection of individual publications that are often cataloged or listed and made accessible in some way. Magazines, journals, and newspapers with Web sites sometimes refer to their back issues as an archive.

3) Web and File Transfer Protocol sites that provide software programs that can be downloaded sometimes refer to the list of downloadable files as an archive or as archives.