before image journal

plural before image journals

1. computingA transaction log acting as a version of a database entry before an update is recorded.

   the server writes the original page on a before image journal maintained on disk (stable) storage.

   1983, Association for Computing Machinery. Special Interest Group on Management of Data (contributor), Proceedings, page 111

   5 more examples

   In the course of the integration effort, and converting an existing relational database management system to use the Data Management (DM) system, some problems were encountered which motivated an extension of the "before image journal" concept.

   1985, ACM Special Interest Group in Operating Systems (contributor), Proceedings of the Tenth ACM Symposium on Operating Systems Principles, 1-4 December 1985, Orcas Island, Washington, Volume 19, page 55

   The before image journal is used for undoing the effects of aborted transactions, and for recovery from system crashes.

   1990, Sayyed M. Deen (editor), Practical Database Techniques, page 58

   The location of the before image journal. An AI journal records changes to a file so that the journal can be used to roll a backup copy of the file forward.

   1990, Kirby McCoy, VMS file system internals, page 49

   The process of recording all operations applied to a database. The type of information recorded depends on whether an after-image or a before-image journal file is created.

   1991, Lilian Hobbs, Ken England, Comprehensive Guide to RDB-VMS, page 334

   If a system crash or power failure occurs, a recovery process mass processes all before-image journals to roll all in-process transactions back to a "clean point" before allowing users back on the system.

   1995 April 7, Norman O. Morgan, “Pick database system and RDBMS”, in comp.databases.pick (Usenet)