On Wed, 2005-11-09 at 19:35 -0600, Tony Caduto wrote:
> <We found PostgreSQL a mature product, but in two things Firebird was
> simply better than PostgreSQL: Two-Phase commit (ok, that is gone with
> PG 8.1), but the second is a SNAPSHOT / REPEATABLE READ transaction
> isolation. I can't live without that when it comes having a stable view
> of data during one transaction, or did that change with 8.1? Is there
> now a SNAPHOST / REPEATBLE READ transaction isolation level available as
> well?>
>
> Just wondering what the PG take on this snapshot repeatable read stuff is.
It has kinda been there for years and is what PostgreSQL uses to achieve
a consistent snapshot with pg_dump. Of course, per spec the DB is
allowed to upgrade the isolation level to SERIALIZABLE from what you
specify you require as a minimum (REPEATABLE READ in this case).
session1: begin isolation level repeatable read;
session2: insert into junk values (1);
session1: rbt=# select * from junk; col ----- 1 (1 row)
session2: insert into junk values (2);
session1: rbt=# select * from junk; col ----- 1 (1 row)
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