On Thu, Sep 23, 2010 at 4:08 PM, Kevin Grittner
<Kevin.Grittner@wicourts.gov> wrote:
> One place I'm particularly interested in using such a feature is in
> pg_dump. Without it we have the choice of using a SERIALIZABLE
> transaction, which might fail or cause failures (which doesn't seem
> good for a backup program) or using REPEATABLE READ (to get current
> snapshot isolation behavior), which might capture a view of the data
> which contains serialization anomalies.
I'm puzzled how pg_dump could possibly have serialization anomalies.
Snapshot isolation gives pg_dump a view of the database containing all
modifications committed before it started and no modifications which
committed after it started. Since pg_dump makes no database
modifications itself it can always just be taken to occur
instantaneously before any transaction which committed after it
started.
--
greg