Hi Milan,

>> Hi Dunbar,

It's Norman. ;-)

<SNIP>

>> Imagine situation, that you have only one query running
>> against DB with simple update of 1 table (no other tables are

involved) and

>> it sometimes goes into deadlock too. That's what I can't understand

to.
If you have ONE transaction then you cannot be getting a deadlock. You
need two transactions for that. Unless, of course, the system itself is
doing something with resources that your transaction requires - but you
say that you are updating only one table. :-(

>> And in this case - I think - doesn't wait or no_wait matter. I'm I

right?
I don't think this scenario is actually a deadlock. :-(

>> Another situation is, that I'm running multiple queries at one time
>> against 1 table, but every of the query is updating records
>> that are not a subject to update for other queries (and again - no

other

>> tables are involved) and deadlock is sometime happening again.

I don't know if it is possible in Firebird, but it might be a deadlock
on indexes perhaps? Hopefully, someone more knowledgeable than me will
chip in here!

<SNIP>

>> Unfortunatelly - in this case it's impossible, because this
>> is just one update query and it's run just once. Transaction is
>> committed right after query is executed (but it can take a few

hours).
As above, one update cannot deadlock, unless triggers and autonomous
transactions elsewhere are involved, events etc? Maybe?

<snip>

>> Another strange behaviour - no exception is raised.

Hmm. This doesn't sound like a deadlock to me.

<snip>

>> Just for you info - I'm attaching 2 dumps of lock manager
>> dumps and it seems that it doesn't contain any deadlock. But I don't
>> understand this dump too much so I can be wrong.

I'm afraid the attachments were removed. If you can, send them to me at
the following emails:

"norman (at) dunbar-it (dot) co (dot) uk" which I'll read when I get
home - my wireless access at work is down for the foreseeable future.
Also send them here to "norman.dunbar.capgemini (at) environment-agency
(dot) gov (dot) uk" and I'll take a look at coffee time, if I can.

I am not the world's best lock manager decoder, and I do need to get
some experience before I write the manual, but I'll do my best.


Cheers,
Norm. (at work!)

Norman Dunbar
Contract Senior Oracle DBA
Capgemini Database Team (EA)
Internal : 7 28 2051
External : 0113 231 2051


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