Hello.

Could you please answer three questions about Slony's transaction
serialization? (I suppose that two first answers will be "yes", but I'd like
to hear the opinions of gurus.) Unfortunately I cannot find direct answers
in the Slony documentation.

1. I have the following non-overlapped sequence of transactions in a SINGLE
(!!!) session (connection) on an origin:

BEGIN;
UPDATE tbl SET a=3D10 WHERE b=3D10;
COMMIT;
--
-- some little delay (e.g. 0.1s)
--
BEGIN;
UPDATE tbl SET a=3D20 WHERE b=3D20;
COMMIT;

The question is: if a subscriber received and processed the result of the
transaction #2, could I be sure that it had also received and committed a
result of the transaction #1? Transactions are not overlapped.


2. I have the following sequence in a SINGLE session (also not overlapped):

BEGIN;
UPDATE tbl SET c=3D10 WHERE d=3D10;
COMMIT;
--
-- some delay (e.g. 0.1s)
--
SELECT nextval('some_seq');  -- =3D> save a result to $some_seq variable

The question is: if subscriber's currval('some_seq') is greater than
$some_seq, could I be sure that the transaction #1 is also processed and
committed by this subscriber?


3. I have the following sequence in a SINGLE session (not overlapped):

BEGIN;
UPDATE tbl SET c=3D10 WHERE d=3D10;
COMMIT;
--
-- some delay (e.g. 0.1s)
--
SELECT max(sl_event.ev_seqno);  -- =3D> save a result to $seqno variable

The question is: if subscriber's max(sl_event.ev_seqno) is greater than
$seqno, could I be 100% sure that the transaction #1 is already processed
and committed by this subscriber?
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