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This is a nice example of the object-based nature of the iSeries.All of these are logical files. If you do a WRKF command over a library with indexes and views, they will all have the LF attribute.
Now, if you do a DSPFD on each kind, you see a difference. Indexes have, in the section called "Data Base File Attributes", an "SQL file type" of INDEX, views have VIEW - subtle, eh? But this is important, as it defines the functions that this object can do, as well as the kind of attributes that apply to it.
Think of this model: *FILE object -- LF attribute (can be any of DSPF, PRTF, PF, PF38, ICFF, etc.) -- -- SQL type = VIEW -- -- SQL type = INDEX -- -- Not an SQL typeEach layer receives the characteristics of the more general layer above it, with more specificity as you go down.
Or in other words, do a DMPOBJ of any of the types, as well as a DSPF, say. You will see that they are all SPACEs where it says OBJECT TYPE-
Below that is a line that says NAME- and on that line it gives a TYPE & SUBTYPE(19 & 01, resp., in hex). These will be the same for all "database" files - probably not message files, as you do not read and write to those in RPG. But them their object type is not *FILE, it is *MSGF. I just tried DMPOBJ on a *MSGF - interesting - the underlying MI type is INDEX - not an SQL index, but a keyed non-database object. TYPE 0E SUBTYPE 03
Enough playing - at the bottom of all this (which is where this is, right? heh), all share common characteristics at the highest level - read, write operations, e.g. Then they get different specializations based on various attributes.
Too much fun? Makes for a very cool system, I think. HTH Vern At 09:40 PM 6/17/2005, you wrote:
To the List, Got into a discussion this afternoon about what the real differences are between logical files, views and indexes. The discussion got a little heated at times so I would ask that some of you well versed members to please help out less fortunate uninformed members about the real physical and logical attributes of these object types. Jack Derham Direct Systems, Inc. -- This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list To post a message email: MIDRANGE-L@xxxxxxxxxxxx To subscribe, unsubscribe, or change list options, visit: http://lists.midrange.com/mailman/listinfo/midrange-l or email: MIDRANGE-L-request@xxxxxxxxxxxx Before posting, please take a moment to review the archives at http://archive.midrange.com/midrange-l.
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