Re: Logical file access paths

["Lewis Libman" <LLibman@xxxxxxxx>]

When I have to change the key in a logical file I would save the record with 
the new key, delete the old record and add the new.

It may be long and weird, but it works for me.

Lewis Libman
llibman@behr.com
714 545 7101 x2118

>>> Colin Thorpe <Colin@IBS-PUBLIC-SERVICES.CO.UK> Wednesday, April 12, 2000 
>7:33:19 AM >>>

Good morning/afternoon,

I have a question regarding access paths.

When I create a logical file over a physical file containing 10,000,000
records, it takes quite some time.

This is presumably building some kind of Matrix/lookup table?

This I can understand.

So then,
Why, when I update the key to this logical in a Do loop (so attempting to
re-read the file) , does it not have to update the matrix/lookup table
(before the re-read) and therefore take a long time to complete.

ie.
KEY SETLL  FILE1
 DOW  *IN31=*OFF
KEY READE  FILE1
 (CHANGE KEY)
 UPDATE  FILE1  (move this records position within the logical
order)
 ENDDO



Thanks in advance  


Colin 
+---
| This is the RPG/400 Mailing List!
| To submit a new message, send your mail to RPG400-L@midrange.com.
| To subscribe to this list send email to RPG400-L-SUB@midrange.com.
| To unsubscribe from this list send email to RPG400-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com 
+---
                                                                                
                                                               
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                               
+---
| This is the RPG/400 Mailing List!
| To submit a new message, send your mail to RPG400-L@midrange.com.
| To subscribe to this list send email to RPG400-L-SUB@midrange.com.
| To unsubscribe from this list send email to RPG400-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com
+---