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- Newsgroups: comp.databases
- Path: sparky!uunet!usc!sdd.hp.com!think.com!cass.ma02.bull.com!pluto.uk03.bull.co.uk!dboyce
- From: dboyce@hemel.bull.co.uk (David Boyce)
- Subject: Re: Hot Standby DBMS's
- Message-ID: <1992Sep9.112749.11492@uk03.bull.co.uk>
- Sender: @uk03.bull.co.uk
- Nntp-Posting-Host: pluto
- Organization: Bull HN UK
- References: <1992Sep7.165029.26587@uk03.bull.co.uk> <BuAHM6.Ds4@cup.hp.com>
- Date: Wed, 9 Sep 92 11:27:49 GMT
- Lines: 45
-
- dhepner@cup.hp.com (Dan Hepner) writes:
-
- >[I wrote:]
-
- >>Interfaces for obtaining journal data from an RM and passing it to an
- >>standby RM would be needed, as would RM-independent methods of recovery
- >>and catch-up. Not beyond the wit of man, I would have thought.
- >>
- >>Obviously the database vendors need to be convinced of the need to make
- >>this interface available.
-
- >Any ideas on how to convince them? In particular, it needs to be
- >shown what can be done using this scheme which the DB vendors
- >could not do themselves. Intuitively, one would say "but it's
- >more open". In what way does this openness benefit anyone?
-
- Obviously, any given DB vendor could (given sufficient justification)
- implement their own RHS (Remote Hot Standby) DB. This justification is
- work for the marketeers, one of whom I am not.
-
- My argument proceeds on the assumption that such justification exists,
- in order to establish the need for an 'open' RHS protocol standard.
-
- Owing to the increase in customer interest and use of Distributed TP
- systems (around Tuxedo, Encina etc.) it seems inevitable that DTP-RHS
- combined functionality will become important for some customers. These
- are the people for whom 'such openness' is important.
-
- Since the working of RHS is based around the ability to restart
- transactions, the extention of this into DTP involves restarting
- Distributed transactions. This requires the cooperation of the
- Transaction Manager - hence the need for an Open RHS protocol.
-
- DB vendors / Transaction Manager vendors which can offer such a
- combination of functionality clearly have the edge in that segment of
- the market which needs it investment).
-
- The bottom line is, what is the size (actual or potential) of this
- market segment? I can't answer that.
-
- --
- David Boyce (David.Boyce@hemel.bull.co.uk)
- Tel: +44-442-884468 BULL HN Information Systems Ltd.
- Fax: +44-442-884570 1, Three Cherry Trees Lane,
- Hemel Hempstead, Herts HP2 7DZ
-