Re: Comments from a Firebird user via Borland Newsgroups.

Bruno Wolff III <bruno(at)wolff(dot)to> writes:
> On Wed, Nov 09, 2005 at 19:35:30 -0600,
> Tony Caduto <tony_caduto(at)amsoftwaredesign(dot)com> 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.

> http://candle.pha.pa.us/main/writings/pgsql/sgml/sql-set-transaction.html
> http://candle.pha.pa.us/main/writings/pgsql/sgml/transaction-iso.html

It's a bit amusing that this person is dissing us for not having
REPEATABLE READ, when what he actually seems to want is SERIALIZABLE
(which we've had since 1999). Certainly REPEATABLE READ does *not*
guarantee a "stable view of data during one transaction" --- see the
discussion of phantom reads in the second link given above.

regards, tom lane