Archiver Process
The archiver process (dmfacp) is responsible for copying the history of operations performed on journaled databases from the transaction log file to the journal files. The archiver process maintains a history of important actions in its own message log file, iiacp.log.
The archiver process removes completed transactions from the transaction log file. For journaled tables, the archiver writes any completed transaction to the journal files for the database. Each database has its own journal files, which contain a record of all the changes made to the database since the last checkpoint was taken. The archiver process “sleeps” until sufficient portions of the transaction log file are ready to be archived or until the last user exits from a database.
Data Manipulation Facility Archiver Process (dmfacp)
Each installation has a single archiver process called the dmfacp (data manipulation facility archiver process). The archiver process is responsible for copying the history of operations performed on journaled databases from the transaction log file to the journal files. Journal files contain the subset of transaction log file information associated with a specific database.
The name of the DMFACP process depends on the installation code. For Ingres installations with the default installation code, the process name is DMFACP. For non-default installation codes, the DMFACP process name is DMFACPxx where xx is the installation code.
Journal Files
Journal files contain the subset of transaction log file information associated with a specific database. Journal files are created (and optionally destroyed) during a checkpoint operation. In the event of a disaster, the database can be rebuilt by restoring the latest checkpoint and applying journal file information.
Disaster Recovery Command
Disaster recovery operations are coordinated by the rollforwarddb command.
Last modified date: 08/29/2024