| 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 | 
    How can we compare the file structure in IBM S/38 with VAX Rdb?
    I knew that is not a true Relational Database, but it has most of
    the features of Relational Database. I knew they do not have the
    optimization and data compression. In term of functionality, is
    there any useful features that S/38 lack off. How about their
    journaling? To me it seems like a transaction audit file that allows
    users to do roll backward and roll forward.  Is there any auto rollback
    functions? Please advise!
    
    Thanks
    Vincent Zao
| T.R | Title | User | Personal Name | Date | Lines | 
|---|---|---|---|---|---|
| 31.1 | Try another Conference as Well | AUNTB::BOOTH | A career of MISunderstanding | Tue Sep 15 1987 18:10 | 4 | 
|       I took the liberty of putting a copy of your note in the HPSVAX::IBM
    notes conference. I think you might stand a better chance of getting
    an answer there.
    ---- Michael Booth
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| 31.2 | Better Late than Never | BMT::MCGOVERN | Mon Apr 04 1988 20:39 | 20 | |
|     
    The S/38 file structure and operating system (CPF) does contain 
    committment control facilities (that's what they call before image
    journaling). Also, CPF has an after image journaling capability
    (which they call "journaling").
    
    The primary weaknesses of the S/38 file system are in the area of
    data recovery.
    	- The 38 has nothing analogous to Volume Shadowing under VMS.
    
    	- If you get a bad block(s) on a disk drive, you have to restore
    	  the data from tape. And if you can't read the tape you're
    	  SOL.        
    
    This stuff is based on Control Program Facility (CPF) Release 8.
    
    
    
    					Mike McGovern
    
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