Re: does unique constraints hurt insert performance

On 13 Aug 2006 12:50:36 -0700, "sunh11373" <sunh11373_at_gmail.com> wrote:

>If I have a large table with a column defined as "unqiue index", will
>it cause performance problem in a high inserting rate environment(all
>single insert)? I heard from someone that if the index is "unique", the
>insert will have to "lock" the top node of the index tree to update the
>index. Thus it will cause a lot of latch contention under hight
>inserting case. But I suspect this is not the case. It might be true
>for some type of databases, but I don't think Oracle does this. Can
>someone offer some insights here?
>
>
>Thanks

I can offer you two insights
- first of all you are in urgent need to stop top-posting to get any further responses
- secondly, you shouldn't listen to the blatant nonsense you 'hear' from someone who apparently knows nothing about Oracle, but you should read the concepts manual yourself.
Locks are not latches and locks do not cause latch contention.

--
Sybrand Bakker, Senior Oracle DBA