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Conference ilbbak::ibi_focus

Title:	FOCUS, from INFORMATION BUILDERS

Moderator:	ZAYIUS::BROUILLETTE

Created:	Thu Feb 19 1987
Last Modified:	Mon May 05 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	615
Total number of notes:	1779

349.0. "Is SEGMENTED best ?" by PEKING::MCSHANEG (Alas poor Yorik..I knew him well) Tue Jun 19 1990 13:42

        
    Which is the best/most efficient way to define the .MAS /.MAS'S
    in terms of access speed and suportability for a large (750000 block)
    multi-table/multi-file Rdb.
    
    A .MAS for each RDB table or one or more multi-segment .MAS's depending
    on FOCUS limitations?                   
    
    Any opinions apreciated.                    
    
    (note also posted in FOCUS & MRE_INTEREST)    
    
                                    
    Gary.

T.R Title User Personal
Name Date Lines

349.1 rdb master thoughts MILPND::MADDEN Tue Jun 19 1990 17:37 16

T.R	Title	User	Personal Name	Date	Lines
349.1	rdb master thoughts	MILPND::MADDEN		`Tue Jun 19 1990 17:37`	16
	Good question! Do we want a multi-relation master with all the joins setup or a master for each relation and use the dynamic join facility? Currently, one disadvantage of the dynamic join is that you can only join one field to one field, however in the 6.0 release you should be able to get around this with the Define field join. Concatenate 2 or more DB fields into a define field and join on that. As far as performance, I'm not really sure if there is a difference. If you were dealing with a FOCUS data file, there is a definite performance advantage with 'static' joins in the master because cross-reference addresses are maintained by FOCUS. With a dynamic join everything is on the fly. However with an .RDB file, I don't think there is any performance advantage. Application wise there could be advantages/disadvantages to both methods. In the same apllication you could use both.

    Good question!  Do we want a multi-relation master with all the 
    joins setup or a master for each relation and use the dynamic join
    facility?   Currently, one disadvantage of the dynamic join is that
    you can only join one field to one field, however in the 6.0 release
    you should be able to get around this with the Define field join.
    Concatenate 2 or more DB fields into a define field and join on that.
    
    As far as performance, I'm not really sure if there is a difference.
    If you were dealing with a FOCUS data file, there is a definite 
    performance advantage with 'static' joins in the master because 
    cross-reference addresses are maintained by FOCUS.  With a dynamic
    join everything is on the fly.  However with an .RDB file, I don't
    think there is any performance advantage.  
    
    Application wise there could be advantages/disadvantages to both
    methods.  In the same apllication you could use both.