Re: LF on 2 files with 'UNION'

[Vern Hamberg <vhamberg@xxxxxxxxxxxxxxxxxxxxxxxxx>]

Sudha

Do the 2 files have the same format, same field names? Just different sets
of data? Then you can build a single-format logical (which SQL can handle)
and specify the 2 files as the based-on files of the CRTLF command.

IIRC, a problem with views, performance-wise, is that the view LF really
stores only the SELECT statement and maybe an access plan, not the actual
access path. So the SELECT is run every time you access the view. This may
be why RPG can't use it, since native IO doesn't know how to run SQL
statements.

HTH

Vern

At 11:48 AM 11/6/2002 -0600, you wrote:
> I am trying to fine tune a performance issue I have in my project where I
> am using a 'Union' over 2 large files.  This returns me a distinct result
> of selected fields from both the files, which is wonderful.  But the time
> taken is quite significant since each call creates a union. I cannot
> create a view on Union, so I am trying to find an easier way to do this
> like say via maybe a LF.  Is this possible?  Else, creating 2 separate
> indexes/views on the 2 files on the selected fields will help?
>
> TIA,
> Sudha
>
> Sudha Ramanujan
> SunGard Futures Systems
> sramanujan@sungardfutures.com
> (312)577-6179