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Re: table indexes



fixed

You can create the index but if you look at the logical file that gets
created as a result of creating the index you will see that it says that it
is being shared with the original index so in effect the only thing you are
doing is creating a name that SQL will never use because it has the
original index. The only thing being stored is the format object. Unless
you tell it no, OS400 will always share an existing index if it can. No
reason to keep and maintain two.

That is why I always look at indexes when I go to work for a company. At
one company I found somewhere upwards 300B bytes of indexes that were not
neeed if you just deleted and recreated the indexes(logical files) and it
looked and said I already have an index I can use.


On Thu, Jul 10, 2014 at 12:45 PM, Briggs, Trevor (TBriggs2) <
TBriggs2@xxxxxxxxxxx> wrote:

Surely that depends upon who or what is doing the telling? If it's the
SQL optimizer telling you then it might have a good reason. If it's your
CEO, then the correct response is, "Yes ma'am,

Trevor Briggs
Analyst/Programmer
Lincare, Inc.
(727) 431-1246
TBriggs2@xxxxxxxxxxx

-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of
Richard
Sent: Thursday, July 10, 2014 2:24 PM
To: 'Midrange Systems Technical Discussion'
Subject: RE: table indexes

I would not think so . the data will already be presented in the
desired
order.

/dick


-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of
Dave
Sent: Thursday, July 10, 2014 1:17 PM
To: Midrange Systems Technical Discussion
Subject: table indexes

Hi,

I have a table with an index already on Columns 1, 2, 3 and 4.

Now I've been told we need another one on Columns 1, 2 and 3.

Is that necessary? I don't see why.

Thanks
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