RE: RPG native to SQL

["Raikov, Lo" <RaikovL@xxxxxxxxxx>]

Richard,

performance is a separate issue. By the way, there is nothing in the AS/400
SQL implementation that would make it as inefficient as you're implying. Of
course, a "typical" SQL RPG is probably more resource-hungry than a
"typical" native RPG, but that's again another story.

I know I have to reacrchitect the application. I am just looking for
somebody who's already been through that. It seems, however, that there is
not a lot on offer. But maybe I should have explained myself in more detail.

Thank you,

Lo

> -----Original Message-----
> From: Richard Jackson [SMTP:richardjackson@richardjackson.net]
> Sent: Wednesday, August 30, 2000 11:17 PM
> To:   MIDRANGE-L@midrange.com
> Subject:      RE: RPG native to SQL
> 
> Native IO has a different view of the tables than SQL IO.
> 
> It is possible to replace each read with a SELECT and each CHAIN/READE
> loop
> with an OPEN CURSOR and FETCH loop.  You can use an IBM SQL language
> extension to fetch and update records using relative record numbers (I
> think
> ...)  But SQL has a lot more overhead per statement and most single
> statements (those not using a cursor) perform a full open and close on the
> file.  Programs using a large variety of SQL statements will probably
> occupy
> several times more virtual storage.  Please note that the ODBC driver
> programs used by the ERP products easily use 30 megabytes of "warm"
> virtual
> storage and sometimes use 100 megabytes.
> 
> You should rearchitect applications to take advantage of the strengths of
> SQL (set selection and update) and to avoid the known issues and "badness
> of
> fit".  In particular, the high cost per statement suggests that you should
> execute several times fewer statements or buy hardware to offset the delta
> and careful tuning or more memory will probably be required.
> 
> 
> Richard Jackson
> mailto:richardjackson@richardjackson.net
> http://www.richardjacksonltd.com
> Voice: 1 (303) 808-8058
> Fax:   1 (303) 663-4325
> 
> -----Original Message-----
> From: owner-midrange-l@midrange.com
> [mailto:owner-midrange-l@midrange.com]On Behalf Of Raikov, Lo
> Sent: Tuesday, August 29, 2000 10:16 PM
> To: 'MIDRANGE-L@midrange.com'
> Subject: RPG native to SQL
> 
> 
> Does anybody have experience converting native RPG to SQL RPG? Are there
> any
> known methodologies? Tools? Consultancies?
> 
> Lo
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