RE: SQL Insert Row as last RRN

Off the top of my head ....Moving the file from one system to another
may require reset also.

Sqlstmt = 'SELECT MAX(' +
%trim(PmFld) +
') FROM ' +
%trim(PmLib) +
'/' +
%trim(PmFile);

EXEC SQL Prepare S1 From :Sqlstmt;

EXEC SQL Declare C1 Cursor For S1;

EXEC SQL Open C1;

EXEC SQL Fetch From C1 Into :MaxInt;

EXEC SQL Close C1;


Sqlstmt = 'ALTER TABLE ' +
%trim(PmLib) +
'/' +
%trim(PmFile) +
' ALTER COLUMN ' +
%trim(PmFld) +
' RESTART WITH ' +
%trim(%char(MaxInt + 1));

EXEC SQL execute immediate :Sqlstmt;



-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Morgan, Paul
Sent: Monday, September 12, 2011 3:07 PM
To: RPG programming on the IBM i / System i
Subject: RE: SQL Insert Row as last RRN

Michael,

IDENTITY column requires maintaining a sequence in the database with
some minor performance issues especially with multiple processes using
the same table. The column sequence could require a reset. It will
eventually wrap around to a lower sequence and throw off your ordering
when it does wrap. It's a similar problem you are having with the RRN.

Is this your interface to the CS 1500? Likely you don't require 24/7 so
having to shut down this single process to occasionally reset is
probably not a problem.

Hope this was helpful,
Paul Morgan

Principal Programmer Analyst
IT Supply Chain/Replenishment

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Koester, Michael
Sent: Monday, September 12, 2011 2:23 PM
To: RPG programming on the IBM i / System i
Subject: RE: SQL Insert Row as last RRN

Kevin, I'd not played with the IDENTITY Column before. I just ran some
tests and found it to be a pretty good solution. It didn't seem to
re-use values from rows I'd just deleted either. Unless someone knows
of any shortcomings of that, I think I'll add that to my CREATE TABLE,
then do the CHGPF trick to so new rows get added to the bottom, and
ensure that all my selects are ORDERED BY the identity column. Perhaps
a tiny bit more effort than I initially planned, but not too much, and
for as critical as sequence is in this case, it gives me more confidence
than RRN.

Thanks for that.

And thanks to everyone else who helped me be not as dumb as I was
earlier today :)
-- Michael K

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Kevin Bucknum
Sent: Monday, September 12, 2011 1:47 PM
To: RPG programming on the IBM i / System i
Subject: RE: SQL Insert Row as last RRN

Instead of a timestamp could you use a IDENTITY column?

Kevin B

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Koester, Michael
Sent: Monday, September 12, 2011 12:05 PM
To: RPG programming on the IBM i / System i
Subject: RE: SQL Insert Row as last RRN

In testing the timestamp idea from interactive sql, I'm showing no
duplicate timestamps (yet), but most are within 1 or 2 microseconds of
the previous row. Who said sql has performance issues?
It looks like I may be best off with an integer that I have to
hand-manage. The template file does have a sequence field, which may be
useful, but did I mention that the whole set of commands passed to the
switch includes commands from a dozen or so templates? Nothing is ever
easy, and the RRN sure looked good, if we could only get SQL to respect
it.

Back to the question I posed earlier: If I did not go the added column
route, would I be safe in changing the file to REUSEDLT(*NO), and adding
ORDER BY RRN(myfile) to the sql retrieving the rows to process?

-- Michael K





Kevin Bucknum
Senior Programmer Analyst
MEDDATA/MEDTRON
Tel: 985-893-2550