Helen:

I really appreciate your message but I am very surprised of what you are saying about my attitude. Yesterday there was no message in the forum between 8:57am and 5:55pm and I thought there was some problem with the forum. English is not my primary language and then perhaps without intention I write something that may be interpreted in a wrong way. I don´t think I wrote anything bad, but if somebody feeled offended I apologize.

When Vlad told me about "wrong usage of gfix" I simply didn´t understand and so I told him how I used gfix and asked him what was wrong to learn it. Today he explained me and now I understand a bit more.

When Carlos suggested me to use IBSurgeon, I told him it was a paid tool. I don´t see anything wrong in this. If I can (and I think every person in the world does the same) I try to use freeware tools.

I will investigate the possible reasons you told me of this problem. I don´t understand your phrase "Allowing the host machine to get into a state where memory and/or disk resources are marginal". Can you please explain me what is the meaning of this?

Thank you very much for the article you referred me about gfix. It is a very good article. I read it but I will read it again to "study" and to learn to use gfix properly.

My preoccupation now is to know what cause this corruption and avoid it to happen again. I tried to check what was happening on that machine at the point where the first consistency check occurred. This PC is used only as a server for my application and so there was no user running another application. In Event Viewer I saw nothing strange and the automatic backup is scheduled to be done at night. Any idea of what other thing I can check?

----- Original Message -----
From: Helen Borrie
To: firebird-support@yahoogroups.com
Sent: Thursday, August 13, 2009 11:46 PM
Subject: Re: [firebird-support] Re: HELP!! Database corrupted


At 11:30 AM 14/08/2009, you wrote:
>Nobody answered my questions and I noticed that there are very few messages in the forum. Is there any problem I don´t know?

Your attitude, perhaps?

>I would really like to know the opinion of those who know much more than I about my questions because I want to know what is the best thing to do.

Really? But when Vlad (who is a Firebird core developer) pointed out your misplaced assumption about a bug in gfix, you seemed to argue that you knew better than he does.

And when Carlos directed you to the best-known tools for recovering corrupt data, you countered that you weren't interested in anything you might have to pay for.

For your future reference, the database engine reports a consistency check error when it encounters any situation where it cannot make sense of the current state of a database and its associated dynamic structures. If possible, it will try to provide clues about the problem (in this case, the transaction inventory page, or TIP, was lost.). That happened because something in your environment corrupted or blocked that structure (in memory or on disk) and the engine could not proceed with its operation. At that point, the database was probably still OK, although not in a state where existing or new connections could function.

Possible hostile external conditions include bad RAM, disk errors, arbitrary locking by an external program such as anti-virus or file backup, even someone trying to file-copy the database while it had attachments. Allowing the host machine to get into a state where memory and/or disk resources are marginal might also give rise to such conditions. There is no magic wand for finding out: it is up to you to discover for yourself who was doing what to what and why - and to prevent it happening again, of course.

The gfix tools are there for solving some (but certainly not all) the problems that might be left behind from such hostile events. However, because gfix -mend actually changes the data in a database, it can be a weapon of mass destruction if used in the wrong conditions: you have a good chance of aggravating a minor (or temporary) condition, as happened to you.

Another time, if you decide to try to use the gfix tools, it would be a really good idea to use them properly and with the proper safeguards taken. You can study this subject in detail in this article:
http://www.ibphoenix.com/main.nfs?a=ibphoenix&page=ibp_db_corr
(available in English and Portuguese).

For now, your primary concern should be to find out what was happening on that machine at the point where the first consistency check occurred -- be it hardware faults, unwise system or software operations or whatever. With luck, there will be a timestamped entry in firebird.log.

./heLen






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