Xref: alice comp.databases.oracle.server:48403 Path: alice!news-feed.fnsi.net!netnews.com!howland.erols.net!newsfeed.mathworks.com!newsfeed1.earthlink.net!nntp.earthlink.net!posted-from-earthlink!not-for-mail From: Mladen Gogala Newsgroups: comp.databases.oracle.server Subject: Re: Oracle Sequences and ACID... Date: Wed, 05 May 1999 22:37:49 -0400 Content-Transfer-Encoding: 7bit References: <372EF22A.649C353E@icb.co.at> X-Posted-Path-Was: not-for-mail X-Accept-Language: en Content-Type: text/plain; charset=us-ascii X-ELN-Date: 6 May 1999 02:36:11 GMT X-ELN-Insert-Date: Wed May 5 19:45:02 1999 Organization: EarthLink Network, Inc. Lines: 33 Mime-Version: 1.0 Message-ID: <3731007D.AE299495@earthlink.net> X-Mailer: Mozilla 4.51 [en] (X11; I; SunOS 5.6 i86pc) Peter Buzanits wrote: > > Do transactions using sequences meet the ACID-requirements for > transactions? > > As I understand, a rollback does NOT undo an increment of a sequence > during the transaction. > > BUT: Doesn't this behaviour violate the ACID-requirements of a > transaction? A means Atomicity. A transaction is performed eighter > completely or NO changes are made at all. If you rollback a transaction, > sequence numbers remain increased (=updated). This can produce gaps in > the sequence, that could be a bad surprise for a developer who relies on > the Atomicity... > > I means Isolation. No change made during a transaction can bee seen > outside. But a sequence increment done by transaction X must be seen by > transaction Y for avoiding double-use of a number... > > So do transactions using sequences meet the ACID-requirements? > > Peter > -- > --------------------------------------------------- > DI Peter Buzanits > mailto:peter@icb.co.at http://peter.icb.co.at > AOL-IM: Buzanits Keys available on PGP-Servers > --------------------------------------------------- Yes they do. If you do rollback, you lose a sequence number. Sequences are not rolled back. -- Mladen Gogala