Re: defining files with sql but using setll/read to access

When you create a index in SQL, the OS just creates a logical file keyed by
the key of the index with all the fields. Looks like any standard logical
except if you do a DSPFD it says file type is INDEX. Your program doesn't
know the difference.

IBM recommends that you create all indexes first as SQL indexes and then
create any DDS logicals. If the index already exists, the OS will just reuse
the index of the SQL Index and the performance is better. If you delete the
index later, the DDS will keep the SQL index.

Unless you rename in your create script, the OS will give it a default name
like CUST000001.

So you have a choice. Create the index with a long name and rename to your
short name

RENAME DRIVER_BY_DRIVER_CODE TO SYSTEM NAME DRIVERI01;

or just create the SQL index and then create your DDS logicals to reuse the
index.

On Thu, Aug 13, 2009 at 4:49 PM, Vern Hamberg <vhamberg@xxxxxxxxxxx> wrote:

Yeah Jim, I believe so - you don't have a subset of the fields in an
index, as you can with standard logical files. With a view, you'd have a
subset and no key - an unkeyed logical basically.

Vern

JDHorn@xxxxxxxxxxxxxx wrote:

I think this means that -when you specify an index the compiler gets

the

physical file definition for all the fields?

Jim Horn

____________________________________________________

------------------------------

message: 7
date: Thu, 13 Aug 2009 14:00:21 -0500
from: Vern Hamberg <vhamberg@xxxxxxxxxxx>
subject: Re: defining files with sql but using setll/read to access

Just like any other PF or LF - for a table, put its name in an

F-spec -

if it has a primary key that you want to use, declare as keyed in

the

usual manner.

For an index, just put its name in the F-spec and declare it keyed.

I think you can even use a view, but it has to be treated as arrival
sequence. Right, you other SQL mavens?

All is the same as you know how to do!!

HTH
Vern

JDHorn@xxxxxxxxxxxxxx wrote:
> As time goes by, I am certainly seeing the advantage of using

sql

to
> access files, especially for search and display.
>
> In an rpg program, what is a good way to use a sql defined file

for

> setll/read access?
>
> Jim Horn
>

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