Re: How many FKs is too many ?

From: Ed Stevens <nospam_at_noway.nohow>
Date: Thu, 21 Oct 2004 08:13:45 -0500
Message-ID: <s2dfn05637qkb5cgskld7btfrseq14t2bk@4ax.com>

On 21 Oct 2004 04:37:03 -0700, krislioe_at_gmail.com (xtanto) wrote:

>Hi Oracle gurus,
>
>I have two tables, one with 100.000 rows and the other with about 4
>million rows. Each table has about 55 columns, with 15 of them refer
>to a reference Table.
>
>If I put FK constraint on these 15 columns (mean I have 15 FKs).
>Is this too many ? will this cause poor performance ?
>Is there any best practices for this ?
>
>Thank you for your help,
>xtanto

Correct me if I'm missing something here ...

Table-A has100,000 rows
Table-B has 4 million rows
Table-C is a reference or lookup type table with some unknown number

of rows.

Table-A has 15 different columns with a foreign key back to Table-C

By definition, a foreign key references the primary key of the parent table.

I don't know about the perfomance impact due to the internals of maintaining 15 FK's on one table, but my head is spinning at what this implies about the design of the data. Doesn't this imply a serious failure at even the first step of normalilzation? Received on Thu Oct 21 2004 - 08:13:45 CDT