Re: Fine point on rowtype and update

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"Pratap" <pratap_fin_at_rediffmail.com> wrote in message news:830861d2.0408222033.7bb1bd74_at_posting.google.com...
> Hi Jonathan,
>
> I am reading your wonderful book. If I remember correctly - You have
> mentioned in one chapter (on indexes) that index entries are not
> maintained when new value in update is same as the old value.

I never read Jonathan's book (sorry Jonathan), but this is true (I also mentioned it in my previous post).

> Does it
> mean that even when there is no change in the index entries, Oracle
> will still check existance of the data in the child table?

Also when a value doesn't change, Oracle performs the following: - locks with a 'row shared table lock' the table(s) referenced by the "modified" attribute(s)
- lookup the value(s) in the referenced primary key(s)

Chris

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