Re: performance when inserting into child tables
- From: Mladen Gogala <mladen@xxxxxxxxxxxxxxx>
- To: oracle-l@xxxxxxxxxxxxx
- Date: Wed, 21 Apr 2004 14:44:56 -0400
Lock is released before commit? That would be something! So, what is to
prevent child from inserting a record with an old value of the foreign key,
the only one that it can see? It looks like a slight violation of the ACID
property. What, exactly, do they mean by "immediately"? If it is "immediately
after the transaction ends", then it's not so new. If the lock is released
before the transaction modifying the parent key ends, there are quite few
nasty possibilities for breaking the integrity. Do you have any Metalink
note? Was the instructor a former second hand car salesman or a real estate
agent?
On 04/21/2004 02:22:51 PM, "Mercadante, Thomas F" wrote:
> Jared,
>
> you said:
>
> "The lack of indexes for the FK's will cause a share lock to be taken
> out on the child table when ever the parent is deleted or updated."
>
> The most recent Oracle class I took said that in 9i, this lock on the child
> table is taken and released immediately. Supposedly to speed the process up
> a bit.
--
Mladen Gogala
Oracle DBA
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