Re: Flamewar object databases vs. relational databases

In comp.databases Carl Rosenberger <carl_at_db4o.com> wrote:
:> Bah. That's one of the smallest possible queries. You also don't need to
:> do it at all if you use _seq.currval on the subsequent rows.
:> Not having subselects - that's where major lossage on the wire occurs.
 

: The execution time of the query does not cause the performance deficit. The : transferral to the client is where the time is waisted.

There's one number, plus associated error & environment info. More than small enough to pack into one TCP frame. That's almost totally unnoticable.

:> Not sure how that relates to multiple-users. The results are isolated
:> from other clients until commit(); who cares what id method you choose?
 

: select(max) is not isolated, _seq.curval is.
: curval is ORACLE-specific and not available on other industrial standard
: databases.

select(max) is isolated if:
A: you are using table-level locking (eg, MySQL) B: you have MVCC (Oracle, Postgres, InnoDB) and are running with

        SERIALIZABLE isolation level

sequences are also available on other DBs.

If all else fails, you can dig around in your manual and find the method to return the pkey of the last inserted row.

This is a non-issue. Don't bother responding -- it's high time this thread sputtered to a gringing halt. Received on Sun Jul 22 2001 - 01:29:40 CEST