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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

458.0. "20 GB Rdb/VMS FOCUS DB" by RDOVAX::HAYDON () Mon Sep 16 1991 14:55

    I am a Rdb/VMS database spec who was called into Blue Cross Blue Shield
    of Flordia.  They are currently in the process of porting a FOCUS
    application form IBM to the VAX platform.  Come to find out that the
    ONE and ONLY reason they will be using Rdb/VMS is that the FOCUS DB
    does not support the file size that this thing might grow to.  I have
    read both notes and do not read too many good things about the Rdb/VMS
    interface.  Someone who I have talked to said that FOCUS will not use the
    optimizer??!!  My biggest concern is that they (IBI, and the customer)
    want to design the database to support the existing code that was
    generated on the IBM platform.  Would anyone care to discuss this
    matter here or offline.  I have asked to IBI folks for some reference
    sites but I would rather here from an internal DEC source.
    
    Thanks in advance....
    
    Steve Haydon  GRANPA::SHAYDON
    
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458.1optimizer...AIMHI::CIONI_LThu Sep 19 1991 13:1526
As far as the optimizer goes, you can still turn on RDMS$DEBUG_FLAGS and
truly see that yes, when the request goes against the database, it will
make use of indexes provided  your request tries to - for example:

if PART_ID is indexed in your database and in your FOCUS request you say

IF PART_ID EQ ...

It will attempt to use the index - on the other hand if you do

DEFINE FILE ...
TEMP/A2 = EDIT(PART_ID,'99$$$$$$$');
END
TABLE FILE ...
IF TEMP EQ ZZ

Since you are doing a selection on a defined field, it probably won't
make use of an index on PART_ID - in this case you might as well say

IF PART_ID EQ 'ZZ$*'  in your FOCUS code - that way you probably will get
the index.

Give me a call.

LisaC
458.2.MAS and .ACX -->RdbRDOVAX::HAYDONThu Sep 19 1991 13:549
    Thanks for the tid bit.  I was also wondering how to physically
    implement the FOCUS files used to access the Rdb DB.  I am thinking
    about .MAS and the .ACX files.  Should you have a separte one for each
    table or 1 per DB.  The FOCUS consultant here on-site seems to think
    that you should group them together by logically related data???
    
    Thanks
    
    
458.3Depends on what you are opting for...AIMHI::CIONI_LFri Sep 20 1991 15:4136
You can either keep them one per table or combine them as you need to.

For example:

	If you had orders with a lot of line items per order, 
	you might want to create a master and .acx file which
	maintains the relationship of the order with the line items
	for you so that you can just go after the one master and
	get information from the two tables at one time.

	Or, you would have to join the tables via a FOCUS command -
	whichever your end-users/you prefer.

	TABLE FILE ORDERS or



	JOIN ORDER_NO IN ORDLINES TO ORDER_NO IN ORDHDR

	TABLE FILE ORDLINES...

	
	Don't know if I would make one for the whole entire database.
	If you do, then chances are that you could be trying to make relation-
	ships between data that really need to be accomplished another way.
	There's a good chance you could get the warning message 'TESTING OF
	INDEPENDENT SETS OF DATA'...also, by making one for the whole database,
	you will only get ties to data that actually make it through the
	entire join path of the data - the use of MATCHES can deal with those
	type of relationships where something is in A and not in B but
	you still want your result to include what info there is in A and
	print out missing values for B - with the master for the entire
	database, you will miss this.

	LisaC