Some AQ managed tables aren't cleared and contain loads of rows

Question

Hi,
I have been running a system made up of two nodes (Oracle XE 10gR2) connected by queues for a couple of years without too much hassle up to date.
Yesterday I found that two of the tables created at the time of the creation of the queue contained a few hundred thousands rows whereas the same tables in a test environment that runs almost the same data were empty. I am talking of AQ$_queue_table_name_H and $AQ_queue_table_name_I.
I stopped the propagation and when the queue was empty I truncated the content of the two tables without problems, but the question is, is there some internal Oracle process that is supposed to take care of this and for some reason is not working?
I checked the documentation but I don't find much details about housekeeping jobs.
Is the monitoring of these tables something that the DBA should add to his/her tasks?
Thanks
Flavio

Answer 1

Hi,
Sorry I missed the XE thing.
So, when you say aq_tm_processes is set to zero as recommended I'm assuming you mean it is defaulted and not explicitly set to zero? You can check using this:
connect / as sysdba
set serveroutput on
declare
mycheck number;
begin
select 1 into mycheck from v$parameter where name = 'aq_tm_processes' and value = '0'
and (ismodified != 'FALSE' OR isdefault='FALSE');
if mycheck = 1 then
dbms_output.put_line('The parameter ''aq_tm_processes'' is explicitly set to 0!');
end if;
exception when no_data_found then
dbms_output.put_line('The parameter ''aq_tm_processes'' is not explicitly set to 0.');
end;
/If it is explicitly zero then remove it:
alter system reset aq_tm_processes scope=spfile sid='*';
--restart the databaseIf it isn't then check that the background processes are running:
select sid,type,program,event from v$session where program like '%(Q%';sys.dbms_aqadm.aq$_propaq handles propagation not queue cleanup activities, the cleanup process should be removing data if the retention is set to 0, this is a background process so its frequency is defined internally.
Can you also check for orphaned messages on your queue?
select count(*)
from AQ$_<queue_table_name>_I i
where not exists (select t.msgid
                  FROM <queue_table_name> t where i.msgid = t.msgid);
select count(*)
from AQ$_<queue_table_name>_T i
where not exists (select t.msgid
                  FROM <queue_table_name> t where i.msgid = t.msgid);
select count(*)
from AQ$_<queue_table_name>_H i
where not exists (select t.msgid
                  FROM <queue_table_name> t where i.msgid = t.msgid);Thanks
Paul
Edited by: pdtill2508 on May 23, 2012 9:55 AM