easy query efficiency question

[John]

Hi,

Could someone confirm that the following query:

update table set x=1, y=1, z=1 where a = 1 or b = 1 or c = 1 or d = 1

is more efficient than this query:

update table set x=1, y=1, z=1 where e <> 1 and f <> 1 and g <> 1

Thanks!

[Patrick]

Hi John,
Your question is in SQL 6.5 discussion Group.
In the both case the optimizer decides a &#39;table scan&#39;
In the first request because of &#34;OR&#34;
In the second because of &#34;Not =&#34;

You could look at the optimizer decision by a quick look at the query plan. Even if the request is not started.

Bye
Patrick


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John at 7/7/01 1:40:56 PM

Hi,

Could someone confirm that the following query:

update table set x=1, y=1, z=1 where a = 1 or b = 1 or c = 1 or d = 1

is more efficient than this query:

update table set x=1, y=1, z=1 where e <> 1 and f <> 1 and g <> 1

Thanks!