Consistant database using archive 0 question

johnyc@mainelink.net wrote: >Our DBA and I are having a discussion regarding the consistancy of a database >that is archived. > >Issue: Informix provides the capability to do a complete archive if a >database while it is in use. > >Question: Can this database be restored without any logfiles (ie to a test >environment) such that the database is consistant. That is, all transactions >that took place during the archive resulted in the archive either ignoring the >transaction completely or resolving the transaction by re-archiving pages that >were already archived and later made dirty during the cource of the archive. > >Example: An archive has archived the pages that contain rows 1 to 100 of a >savings account file. Money is transferred from the account in row 200 to the >account in row 10. What happens during the archive?? Is the data in row 200 >left untouched, or does the archive go back and get row 10?? > >One of us beliefs that the archive goes back and gets row 10 before the >archive completes. The other beliefs the archive only archives the before >image of the page containing row 200. ( I won't say which is which so that I >won't gloat when I am right :-) ) > >It would be very helpful if anyone responding would reference where we might >verify the information. We have read the DBA manuals, the DBA training >manuals, and the survival guide and cannot agree on the answer. > >Thank you > >John Callaway >Bath Iron Works > Reference Informix OnLine Administrator's Guide (Version 5.0) Chap 4-25 Quote "During an archive, tbtape periodically scans the physical log looking for "before-images" that contain timestamps that are less than the begin-archive checkpoint timestamp. Each "before-image" page that meets this criterion is copied to the archive tape." Maybe it just that I have been a Informix DBA since 1986 and have learnt how to interpret Informix documentation, but I believe the paragraph quoted above speaks for its self. So the answer to your question is tbtape writes the before image of row 200 to the archive. _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ Gordon E. Hooker MACS PCP 25 Clarke Street Ripley Queensland Australia Phone 61-7-32940555 Email gordonh@acslink.net.au _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ It is far far better to remain silent and appear a fool then to open ones mouth and remove all doubt. Anon.