propagator/receiver sessions

Hi

We have a multimaster replication with three sites: A, B and C. A and B are synchronous and C is async.

We use the same user (called propagator) for the propagation and receiving. For the administration there is a different user.

I want to understand how is the procedure to start sessions for the propagattion/receiving of transaction during synchron and asynchron replication.

When I issue the following SQL:

select 'A' SITE,

(select count(*) from v$session_at_A) SESSIONS,
(select count(*) from v$session_at_A where username = 'PROPAGATOR')
PROP_RECV
from dual
union
select 'B' SITE,

(select count(*) from v$session_at_B) SESSIONS,
(select count(*) from v$session_at_B where username = 'PROPAGATOR')
PROP_RECV
from dual
union
select 'C' SITE,

(select count(*) from v$session_at_C) SESSIONS,
(select count(*) from v$session_at_C where username = 'PROPAGATOR')
PROP_RECV
from dual

I get

SITE           SESSIONS           PROP_RECV
A                4154                       419

B                2865                     2172

C                  520                          0

I don't understand why on the asynchron side (C) we have 0 (sometimes 1) sessions and for the synchron side so many.

>From the numbers I shall understand that sessions are created one per user only for synchron replication and not for async. Is this right?

Is there a way to differentiate receiver's sessions and propagator's sessions?

Regards
Pablo Received on Thu Oct 05 2006 - 03:57:42 CDT