Re: Best approach for Embedded SQL SELECT in V7R1

I use SQL exclusively for I/O in screen programs and was pleasant surprised
when I first used it that it actually made coding simpler and yes I always
use a data structure or records array to read records and I almost always
map to a user space. It makes it very, very fast.

If you are interested, I can send a module doing a single page load written
using subfiles and SQL.


On Tue, Nov 6, 2012 at 7:37 AM, Michael Ryan <michaelrtr@xxxxxxxxx> wrote:

Hi folks...looking for opinions/ideas here. I'm working with a program that
declares a cursor, then does a FETCH NEXT to iterate through the result set
and fill a subfile. It looks like this:

DECLARE C1 CURSOR FOR
Select * From Inventory
Where...<where and order by clauses>
...
Exec SQL
Fetch Next
From C1
Into :WkInventory;

Where WkInventory is an externally described DS based on the Inventory
file. The data is then moved from WkInventory to the subfile, and the
subfile is eventually displayed.

I *think* that performance would improve by FETCHing multiple rows into a
MODS or an array in a data structure, rather than esentially performing RLA
with SQL. Recently upgraded to V7R1, so I'm looking for the best approach
at this OS level - I know I can do more than I could do in V5R4. My first
thought is a MODS and specifying a number on the FETCH. But then I need to
be concerned about 're-FETCHing' when I run out of rows for my subfile,
right? Would an array make more sense than a MODS?

I want to use SQL where it makes sense and RLA where it makes sense. I need
to work through this concept so I can use this technique as I go forward.
Ideas, opinions, code samples all welcome. Thanks in advance!
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