%META:TOPICINFO{author="ChrisBartram" date="1170389045" format="1.1" version="1.2"}%
%META:TOPICPARENT{name="Hp3000DatabaseLogging"}%
---+ Getting Database activity reports from logging data on the HP3000

Image logging records every change made to the logged database(s). Every database accessor that opens the database in a mode capable of modifying data is recorded in the log files, with information including the Job/Session number, logical device, logon info, program used, and date/time. Database information logged includes records added (with complete record image), records deleted (again with a copy of the entire record that was deleted), and changes (which records the key information, followed by the changed fields with old and new values of each). 

There are various software packages that can read these log files and produce very comprehensive records of database modifications.

Note for users attempting to write their own programs; the Image log file records are variable length record format, with the first 11 or so words being in a format documented under the "WRITELOG" Intrinsic (which Image uses to record the data); the remaining data in each record after that point is in the format as documented in the Image manuals. Accessing the data is somewhat tricky as the Image portion of each log record contains numerous "pointers" to fields farther along in the record. Also, Image fields are recorded by item numbers, so your program will need to have access to the real database and use DBINFO to get the actual set/item names (or you'll have to hard-code a list).


-- Main.ChrisBartram - 18 May 2006