Re: User-facing aspects of serializable transactions

On Thu, May 28, 2009 at 8:43 AM, Peter Eisentraut <peter_e@gmx.net> wrote:
> On Thursday 28 May 2009 15:24:59 Heikki Linnakangas wrote:
>> I don't think you need that for predicate locking. To determine if e.g
>> an INSERT and a SELECT conflict, you need to determine if the INSERTed
>> tuple matches the predicate in the SELECT. No need to deduce anything
>> between two predicates, but between a tuple and a predicate.
>
> That might the easy part.  The hard part is determining whether a SELECT and
> an UPDATE conflict.

What's hard about that?  INSERTs are the hard case, because the rows
you care about don't exist yet.  SELECT, UPDATE, and DELETE are easy
by comparison; you can lock the actual rows at issue.  Unless I'm
confused?

...Robert