Re: Declare a key on a subfile... is it possible?

Must be Friday...

Michael Schutte
Work 614-492-7419
email  michael_schutte@xxxxxxxxxxxx


                                                                           
             Scott Klement                                                 
             <rpg400-l@scottkl                                             
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             04/14/2006 04:09          Re: Declare a key on a subfile...   
             PM                        is it possible?                     
                                                                           
                                                                           
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> Scott, I myself, was only saying that dimming an array limits you to the
> size of dim.  But lets say that you don't use all the elements in the
> array.  Now your program is taking up space to account for those empty
> arrays, where with a temp file, it'll grow with you.

And, as I've already replied to you, the file won't be any better.  In the
extreme case, my array with have 9999 elements, since that's how big
SFLSIZ can be.

      D  Zip            s              9P 0 dim(9999)

Each entry is 5 bytes, theres 9999 elements. So that's 49995 bytes of
space.

On the other hand, if you coded the following file:

      A                                      UNIQUE
      A          R ZIPREC
      A            ZIPCODE        9P 0
      A          K ZIPCODE

Then just create it as an empty file:

    crtpf qtemp/ziptest srcfile(mylib/qddssrc)

When I check the size of that file with DSPOBJD, here's what it shows:

  Opt  Object      Type      Attribute               Size
       ZIPTEST     *FILE     PF                     49152

So, without ANY records in it, it's already about the same size as the
array. Sure, you're saving 800ish bytes, but those 800 bytes are
completely insignificant (as is 50k, by the way, on todays computers)

Now, if he only needed 9800 elements in his array, then the arrray would
actually use less memory than an EMPTY file.

The iSeries single-level store will cause the parts of the array that
aren't getting any use to be shuffled out of physical memory and onto disk
if the system is short on memory, so the difference between a disk object
and a memory object aren't important, either.

Furthermore, where do you think subfiles are stored?  In magic elfenland?
No, they're stored in memory.  If each subfile record takes up, say, 60
bytes of memory, then setting SFLSIZ(9999) means that you're using 600k of
memory.  Yet, you don't seem too worried about setting SFLSIZ too high for
the number of loaded records, yet you're worried about the array.  It
doesn't make sense.

> I don't think any of us tried to offend you.

I wasn't offended by your post, I just didn't agree with you.  Alan
Shore's post offended me, however.
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