Re: Index Question

Well, I inherited these databases and there's a lot wrong with them. All the character fields are defined as CHAR() even though many of them are mostly empty. What I'm really trying to figure out is whether this index (and many others like it) are worth their keep.

Van

Jens Mayer wrote in message <37384612.2291755_at_news.space.net>...
>On Mon, 10 May 1999 17:58:27 -0400, "Van Messner"
><vmessner_at_netaxis.com> wrote:
>
>>Under version 7.3:
>>I have a 1 Gig table with 9 million rows. One column is a number(12).
This
>>column is not unique and there are about 500 rows for each different
number.
>>The column has a non-unique index which takes about 300M. The table is
>>updated frequently.
>>
>>Is this index giving enough benefit to justify the additional 300 Meg?
It's
>>reasonably selective but the column on which it's based is a short number.
>>Based on the size of the index it seems like the index values might be
>>longer than the column values. Is that a problem?
>>
>>Thanks
>>
>>Van
>>
>>
>
>Hi Van,
>
>As far as I know, your index is so huge because Oracle uses about 22
>Bytes to store a number-value. the length of the value has no
>influence on the internal size of a number.
>Is it important for you to store the values as number ? Key values may
>be stored as char(12) as well and this will take only about 12
>Bytes...
>
>
>Jens Mayer
>Rat & Tat Beratungsgesllschaft mbH
>Muehlenkamp 6c
>22303 Hamburg
Received on Tue May 11 1999 - 18:08:22 CDT