Subject | Re: Another Issue with JBoss |
---|---|
Author | Roman Rokytskyy |
Post date | 2002-11-21T18:28:40Z |
I would say this is a bug in driver. There is an open connection to
the database if commit() or rollback() fails. See my previous post.
Roman
the database if commit() or rollback() fails. See my previous post.
Roman
--- In Firebird-Java@y..., Nickolay Samofatov <skidder@b...> wrote:
> Hello, Stephan !
>
> Thursday, November 21, 2002, 6:10:10 PM, you wrote:
>
> > I was surprised to read in your reply to Phil about the high
> > severity of the well-known "OBJECT IN USE" bug. We have databases
of
> > the mentioned complexity of several hundreds of database objects.
On
> > nearly every release of our application we have to make some
changes
> > to the data schema and the problem arises very often. As a
> > workaround since almost three years we just close the connection
> > (the file gets closed) and we resubmit the last sql statement
> > through the newly opened connection. From your mail it seems not
to
> > be enough and we are in risk to corrupt the databases. Should we
> > change our strategy?
>
> Maybe. After dropping of index some internal structures may still
point
> to the page where it was. If you try to update or insert some data
to
> this table you will very likely get a message that database is
> corrupted (restart will cure the problem since no actual corruption
> happened). But there is a possibility under some usage scenarios
that
> type of page that old index points to will be index page. Database
> corruption is possible in this case. In general, chances for real
> corruption are very slight (much less then from bugs in GC
routines).
> Reported corruption happens relatively often, but actual corruption
> really rarely.
>
> Closing all SS connections may not cure a problem completely,
> because metadata caches may not get deleted when you close all
> connections. Closing all CS connections is equivalent to server
> restart. Backup/restore is recommended mainly because of GC bugs
> that sometimes arise during complex metadata operations.
> But performing complex metadata operation in one step was nearly
> impossible before FB1.5 because of "OBJECT IN USE" problem
> so this problem also appears rarely.
>
> I would recommend backup+check for restorablity of backup before and
> after metadata alteration anyway.
>
> --
> Best regards,
> Nickolay Samofatov mailto:skidder@b...