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- From: jgordon@ssf-sys.DHL.COM (Jim Gordon)
- Newsgroups: comp.databases.informix
- Subject: Re: tracking data changes (a request for advice/information)
- Date: 17 Nov 1992 19:38:06 -0500
- Organization: Mailing List Gateway
- Lines: 45
- Sender: walt@mathcs.emory.edu
- Distribution: world
- Message-ID: <1ec39eINNbci@emory.mathcs.emory.edu>
- Reply-To: jgordon@ssf-sys.DHL.COM (Jim Gordon)
- NNTP-Posting-Host: emory.mathcs.emory.edu
- X-Informix-List-ID: <list.1615>
-
- >
- > I need the ability to track any changes to a large OnLine database, to the
- > table/row/column level*, without having to constantly scan all of the tables,
- > and without building any special abilities into the applications doing the
- > adding/deleteing/updating.
- >
- > The former is no good because:
- >
- > 1) It would use up too many resources, and
- > 2) It wouldn't give me the changes in the order they happened (fairly important)
- >
- > The latter is no good because:
- >
- > 1) Too much existing code would have to be changed, and
- > 2) doing batch adds/updates/deletes with isql would screw things up
- >
- > The most obvious solution I can think of is having transaction logging turned
- > on, and monitoring the logical log. I guess my questions are:
- >
-
- I can't comment on the Online Log idea but another solution would be
- to wait for Online 5.01 and use the Triggers to write records to log
- files after every insert/update/delete on the tables and columns you
- need to monitor.
-
- This would avoid any necessity to play with the online logs and would
- not require any changes to the applications. It would also allow you
- to more easily tailor the logging to only those parts of the database
- you need to check on and allow for building a simpler database query
- process rather than a (probably) C extraction process from the logs.
-
- It is not possible to access the performance hit this will have on the
- application. But the Stored Procedures seem to work fine in 5.0.
- Also you run the risks of bugs in the Trigger system. Against this
- Informix have given themselves considerable extra time to get Triggers
- reasonably clean. They were supposed to be in 5.0 but at release time
- were not stable enough so they left them out.
-
- Cheers - Jim
- --------------------------------------------------------------------
- Name: Jim Gordon Internet: jgordon@ssf-sys.DHL.COM
- Company: DHL Systems Inc Phone: (415) 358-5911 (Work)
- Address: 1700 S. Amphlett Blvd. (415) 882-9728 (Home)
- San Mateo, CA 94402 Fax: (415) 571-6429
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