AW: unexpected table lock
> -----Ursprüngliche Nachricht-----
> Von: informix-list-bounces@iiug.org
> [mailto:informix-list-bounces@iiug.org]Im Auftrag von
> minnickbrian@aim.com
> Gesendet am: Mittwoch, 15. März 2006 17:16
> An: informix-list@iiug.org
> Betreff: Re: unexpected table lock
>
> >>> In my opinion the DBSA has to be able to monitor the
> >>> status of a table at all times.
> >>> How do you think about it?
> >>>
> >> if that is the case and your apps fall over then:
> >>
> >> set isolation to dirty read;>
> >Yes but the results may be wrong
>
> >I'm searching for a list of adminstrative task and the implied lock
> modes.
> >Didn't find anything in the manuals.
>
> Has this table been recreated recently and without row-level locking?
> You may be
> hitting a page-level lock (default), blocking your access. Run
> dbschema -t tablename -ss -d databasename> to view the locking leveling you are using.
The table has row locking like all other in our production environment.
It is Fragmented (Round Robin). Could this imply a table lock while calling
the status of the table with dbaccess?
Reinhard.
--Yes but the results may be wrong
--I'm searching for a list of adminstrative task and the implied lock
modes.
--Didn't find anything in the manuals.
--Any help would be appreciated.
if you have an oltp application which will insert data always.
so it is impossible to say at time xx (say 12:00) there will be no
rows inserted.
Then no matter what you do the result will always be wrong.
ex:
you take a snapshot at 12:00
a user has started a trx at 11:59 and this one will commit at 12:01
or rollback; that is what you do not know at 12:00!!! this is
regardless
of what isolation level you set. with all but dirty read you will hit a
lock.
another way is look at onstat -t output; but that has the same effect
as above.
dono the equivalent sql to obtain this out of sysmaster.
you have to look in $INFORMIXDIR/etc/sysmaster.sql
probably a join with sysptnhdr and systabnames; joining partnum???
CAREFULL querying sysmaster... do it on test system first please
Superboer