RE: Working with tables, best method

Doug,

Let me throw in two cents before Joe jumps in.. You are really talking about two distinct scenarios here. The issue of DDS -vs- DDL defined tables is question one, and then random I/O -vs- set-based I/O.

The first of these (DDL / DDS) is much easier to decide. DDL defined tables will have performance advantages over DDS defined files. There are not many (any?) advantages to using DDS...

The second issue relates to runtime performance, and is heavily influenced by the design of your application. In many applications, I/O is highly random for a single transaction, meaning that RPG's ability to chain by key to retrieve a single row of data should be able to outperform a single-row fetch using SQL. If the design of your application processes entire batches, then SQL set-oriented I/O *could* outperform the traditional alternative.

JMO,
Eric

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx]On Behalf Of Doug Palme
Sent: Thursday, February 14, 2008 11:12 AM
To: RPG programming on the AS400 / iSeries
Subject: Re: Working with tables, best method


Without disagreeing with you Joe and with trepidation that I am opening up
a can of sardines here; would you be willing to expound on the argument
that I/O is faster than SQL? The reason I ask is there is an intense
debate going on here locally over the issue of DDS defined PF's versus DDL
defined files and whether SQL is faster or slower than normal I/O.

Any additional information would be appreciated.....

Douglas