Re: table indexes

[Booth Martin <booth@xxxxxxxxxxxx>]

The boss said to do it so yes, it is necessary.  "'Shut up' he 
explained" remains my favorite quotation of all time.  :)

One question that comes to mind is: Will the records need to be 
processed sequentially?  I ask this because I have seen files with 
several fields as key and the first or second key is unique.  Or, 
conversely, uniqueness requires all fields, and processing with less 
than the full key leads to unexpected results.  In other words, design 
decisions that didn't do what the designer thought they were doing.

I put this out there as a discussion point, in case there are some 
implications you might want to prepare for as a result of this design 
decision.


On 7/10/2014 1:16 PM, Dave wrote:
> 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