Re: User-facing aspects of serializable transactions

On Wed, 2009-05-27 at 18:54 -0500, Kevin Grittner wrote:
> I've gotten the distinct impression that some would prefer to continue
> to use their existing techniques under snapshot isolation.  I was sort
> of assuming that they would want a GUC to default to legacy behavior
> with a new setting for standard compliant behavior.

That sounds like the "migration path" sort of GUC, which sounds
reasonable to me.

But what about all the other possible behaviors that were brought up
(mentioned in more detail in [1]), such as:

1. implementation of the paper's technique sans predicate locking, that
would avoid more serialization anomalies but not all?
2. various granularities of predicate locking?

Should these be things the user controls per-transaction? If so, how?

Regards,Jeff Davis

[1] http://archives.postgresql.org/pgsql-hackers/2009-05/msg01128.php