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Home -> Community -> Usenet -> c.d.o.misc -> Re: How taxing are constraints?
On Thu, 29 May 1997, Will Kooiman wrote:
> Date: Thu, 29 May 1997 22:33:10 -0500
> From: Will Kooiman <wkooiman_at_csac.com>
> Newsgroups: comp.databases.oracle.misc
> Subject: Re: How taxing are constraints?
>
> Most constraints have negligible performance degradations. I would be
> surprised if you could measure the performance impact of adding NOT NULL
> on a few columns.
>
> However, if you are stuffing spaces into a column simply to get around a
> NOT NULL constraint, you WILL see a performance degradation. Oracle
> stores null values very efficiently. I've seen systems that have NOT
> NULL on every column use 3 times the storage as they did otherwise.
I think you're implying that the tables with all the NOT NULL fields were that much bigger because they put spaces in there, correct? It sounds like if we're merely enforcing what we expect to do anyway (we really need the data in these fields, so we wouldn't be putting "filler" in them to get around the NOT NULL's), that the table wouldn't be any bigger and performance would not be affected noticably. If that's true, then I'm set.
Thanks for your help.
DDDD David Kramer dskramer_at_concentric.net DK KD http://www.concentric.net/~dskramerDKK D
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