Re: Loading an array from file vs external described data structure.

John:

You should watch the last episode of Bob Cozzi's Tuesday Tips for Nov. 23, 2010, entitled "Faster Database I/O" available here:

http://systeminetwork.com/tuesdaytips

The key concept is to do the reads into and writes from the data structure (so you don't end up with the fields "scattered" in working storage.)

Hope that helps,

Mark S. Waterbury

> On 12/6/2010 7:22 PM, John Rusling wrote:

This is puzzling, to me.

When I use an F-spec for the file named lmit, I can auto-load an array thus -

flmit if e k disk
...
d myds ds
d custarrdata
d lcust1 overlay(custarrdata)
d lcust2 overlay(custarrdata:*next)
d lcust3 overlay(custarrdata:*next)
d lcust4 overlay(custarrdata:*next)
d lcust5 overlay(custarrdata:*next)
d lcust6 overlay(custarrdata:*next)
d lcust7 overlay(custarrdata:*next)
d lcust8 overlay(custarrdata:*next)
d lcust9 overlay(custarrdata:*next)
d lcus10 overlay(custarrdata:*next)
d custarr overlay(custarrdata)
d dim(10) like(lcust1)

but when I remove the F-specand c/ to an external desc data struc it doesn't work

d lmitds e ds extname(lmit)

*RNF3315 20 10 The Name entry is already defined on a Definition
Specification; defaults to blanks.
*RNF7030 30 1 The name or indicator is not defined.
*RNF7301 30 1 Position of subfield is greater than length of data
structure; specification ignored.


Nothing else changed, only changed from an F-spec to ext desc data struc ? ?

Anyone have any explanation for this or run across this before?

Tia

John B