Comments on: Journal

By: tomliotta

tomliotta — Sun, 12 Dec 2010 10:55:28 +0000

You can’t use APYJRNCHG to apply journal images to a different file.

Use RTVJRNE or the Retrieve Journal Entries (QjoRetrieveJournalEntries) API to retrieve entries or DSPJRN to output journal entries to an outfile.

For all of them, the record images will be in the Entry-Specific Data (ESD) field. This field can be processed through a program described file or copied over a data structure that matches the record format.

Records that were INSERTed can be directly processed through a program-described file. UPDATEs take a little more work — the related record can read (for update) into a data structure, the ESD can be laid over the structure and then the record can be rewritten. The ESD must be checked first in order to know which record needs to be read. DELETEs will be processed something similar to INSERTs in that the ESD tells which record to DELETE.

Tom

By: astradyne

astradyne — Thu, 28 Sep 2006 09:06:54 +0000

Pollywantsacracker is right, HA applications such as Data Mirror Transformation Server receive the journal entries for a file and then apply them to a “mirrored” file. I don’t believe they use APYJRNCHG because they allow for data to be transformed between systems if required – e.g. changing value “1″ to “Y” and “0″ to “N” type of thing.

By: pollywantsacracker

pollywantsacracker — Wed, 27 Sep 2006 11:18:27 +0000

You could also use RCVJRNE to get the journal entries and process them. You need to keep track of the last journal entry processed so that you can restart your process if needed.

I’ve seen this process in use at another company and it worked well once they worked through the programs involved.

If your files are the same…I’ve never tried it, but could you just use APYJRNCHG to apply the changes to different file than the host? There must be something like this that the high availability vendors are doing with the remote journals.