Hi,

we encountered a very strange problem.

(XP - dbisam 424 B1, use dbisammm  - Delphi 7 - local tables, single
computer with an UPS)

we have an apllication, running on more than 1000 customer sites.
With one customer they sometimes see that records spontaneous dissapear on
at least two parts of the application.
I checked all the code and even have in all the BeforeDelete en AfterDelete
events and the Engine.OndeleteTrigger filled with a function to registrate
deletes in a special separate table (and there are no records in this table
from "unwanted" deletes).

This application runs at so many sites and no-one is complaining, so I am
thinking of a hardware or Windows problem.
What could be the solution ? In wich direction should I search ?


with kind regards
have a nice , bugfree 2007

Erik

Erik


Two thoughts ocurr:

1. corrupted index / corrupted table - try a repair

2. a filter (or live result query) where one of the fields in the filter is changed so as to move the row "out of view"

Roy Lambert

Hi Roy,

thanks for replying.
There's nothing corrupt and the filters are not in use.
I have the tables here at my office and the problem is that I cannot
reproduce the problem here on my computers ( several tried )

Erik


"Roy Lambert" <roy.lambert@skynet.co.uk> schreef in bericht
news:F8B59F46-F30F-487E-8D6A-72CC3F6A5729@news.elevatesoft.com...
> Erik
>
>
> Two thoughts ocurr:
>
> 1. corrupted index / corrupted table - try a repair
>
> 2. a filter (or live result query) where one of the fields in the filter
> is changed so as to move the row "out of view"
>
> Roy Lambert
>

Erik


Does that mean you can see the records?

Roy Lambert

Roy,

the records that are dissapeared are not visible anymore whith dbsys
could they be visible whit a hex-editor ? I don't know where and how to look
( I mean: I don't know how the .dat file is constructed).
are deleted records still in the .dat file or : at which point are they
removed from the file itself ?

Erik

"Roy Lambert" <roy.lambert@skynet.co.uk> schreef in bericht
news:38E710A7-328B-4935-82DF-B88A276BF6C0@news.elevatesoft.com...
> Erik
>
>
> Does that mean you can see the records?
>
> Roy Lambert
>

Erik

My suggestion, add an audit routine just before any delete in these
situations.
Sometimes, users delete and claim "I do not do that".

Eduardo

Eduardo,

I have a confirmation message before the Delete will executed.

Erik

"Jose Eduardo Helminsky" <contato@hpro.com.br> schreef in bericht
news:66D78D2D-846A-4269-B629-FD360298498C@news.elevatesoft.com...
> Erik
>
> My suggestion, add an audit routine just before any delete in these
> situations.
> Sometimes, users delete and claim "I do not do that".
>
> Eduardo
>

Erik


Another question has occurred to me - how do you know the records were ever in the table?

To answer your question - records are not deleted as such just a flag set to indicate they are available for reuse. The next addition to the table will then use one of these available slots rather than extend the file thus overwriting the data. Only when the table is optimised are any deleted records removed.

Roy Lambert

Roy,

OK.
I'll try to search for those records.

Could the problem be related to windows buffering or a damaged hard disk
(the customer don't get hardware failure messages) , because some people are
using this part of the application (without complaing about losing records)
I really can't believe it's a problem in my application....

Erik



"Roy Lambert" <roy.lambert@skynet.co.uk> schreef in bericht
news:9A16D9D4-1535-41BA-B283-219E956E2217@news.elevatesoft.com...
> Erik
>
>
> Another question has occurred to me - how do you know the records were
> ever in the table?
>
> To answer your question - records are not deleted as such just a flag set
> to indicate they are available for reuse. The next addition to the table
> will then use one of these available slots rather than extend the file
> thus overwriting the data. Only when the table is optimised are any
> deleted records removed.
>
> Roy Lambert
>

Erik


I doubt that its windows buffering. If it were then shutting down and restarting would probably resolve things.

You can check if its a hard drive problem - defrag the disk with something like Norton Speeddisk then validate the tables. If its a hard drive problem I guarantee they'll show up corrupted.

How about some more details? EG is the app single user/multi-user file sharing/client server. Also what are the users doing when they can't see the records, and what were they doing before?

Roy Lambert