Re: Encoded Vector Indexes

[Vern Hamberg <vhamberg@xxxxxxxxxxxxxxxxxxxxxxxxx>]

Jerry, EVIs are a different kind of index, as you know. They cannot be used 
for ordering records, only for record selection. This could be a reason to 
keep the non-EVIs, if they are used to support an ORDER BY. Also, I don't 
know whether and EVI index can be used in RPG, as a logical file can. 
Certainly it would have unpredictable order.

EVIs are cool and performance is supposed to be better in V5R2 - there were 
some problems earlier. No details, just scuttlebutt.

HTH

Vern

At 07:17 PM 10/23/2003 -0400, you wrote:
> If I already have SQL indexes existing on my system, is there any notable
> reason not to replace them with EVI's?
>
> Since the system must already maintain the existing index, wouldn't the
> overhead associated with maintaining the EVI be somewhat similar to
> maintaining the existing index? The fields used to create the EVI would be
> identical to the existing index. The only difference is that it would be
> (re)created as an EVI. Wouldn't this be of benefit if it were only to reduce
> the physical size of the index? (And I'd think the EVI would be faster too).
> I'm running V5R2. Comments???
>
> Regards, Jerry
>
> Gerald Kern
> IBM Certified AS/400 RPG IV Developer & RPG IV Programmer
> MIS Project Leader, Lotus Notes/Domino Administrator
> The Toledo Clinic, Inc.