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Conference ulysse::rdb_vms_competition

Title:	DEC Rdb against the World

Moderator:	HERON::GODFRIND

Created:	Fri Jun 12 1987
Last Modified:	Thu Feb 23 1995
Last Successful Update:	Fri Jun 06 1997
Number of topics:	1348
Total number of notes:	5438

1130.0. "2 process model" by NHAVEN::FLEMING () Thu Apr 02 1992 22:53

    The X/Open DTP model allows the RM <-> TM interface (a.k.a. XA) and the 
    RM <-> AP interface (a.k.a. RM APIs) to be in separate processes. This 
    was done primarily so that the critical parts of the TM and DBS are in a 
    separate address space from the user written application.

    Does anyone know which, if any DBs support this model ?

T.R Title User Personal
Name Date Lines

1130.1 Why do you ask? 8596::BERENSON Lex mala, lex nulla Fri Apr 03 1992 00:11 10

T.R	Title	User	Personal Name	Date	Lines
1130.1	Why do you ask?	8596::BERENSON	Lex mala, lex nulla	`Fri Apr 03 1992 00:11`	10
	On UNIX systems the RM and AP are nearly always in separate address spaces (ie, two different processes) and communicate via interprocess communications. On VMS systems there is support for hardware protection modes and, in the case of Rdb/VMS at least, the "critical portions" of the database manager run in an inner hardware mode. This provides equivalent protection at a lower communication cost between the RM and AP. Hal

On UNIX systems the RM and AP are nearly always in separate address
spaces (ie, two different processes) and communicate via interprocess
communications.

On VMS systems there is support for hardware protection modes and, in the
case of Rdb/VMS at least, the "critical portions" of the database manager
run in an inner hardware mode.  This provides equivalent protection at a
lower communication cost between the RM and AP.

Hal