Re: Two users, one query, two optimizer plans

See my earlier message for full explanation, but, yes, it turned out that the join predicate was missing.

On 1/18/06, Boris Dali <boris_dali_at_yahoo.ca> wrote:
>
> How many rows do you get back for users A and B?
> The CBO expects one row back for both, but I'd guess
> that A gets by far more rows in the result set than B.
>
>
> It looks like DM_GRANTPARTICIPANT is policy protected
> on company_fk column? Since there's an index range
> scan access path for A user on this table, I'd guess
> that the RLS predicate is not the only one in the
> query? I would also guess that this additional RLS
> predicate (probably treated by the CBO at the
> selectivity of 5%) simply makes it look to the CBO as
> a cheaper one to access than DM_ISSUEGRANT and hence
> the order is switched (BUFFER SORT operation seem to
> go on a more expensive row source)
>
> But why MERGE JOIN CARTESIAN? Any chance that a join
> predicate is missing?
>
> Thanks,
> Boris Dali.
>
> --- Paul Baumgartel <paul.baumgartel_at_gmail.com> wrote:
>
> > User A is schema owner. User B has select on user
> > A's objects, and is
> > subject to row-level security policy on user A's
> > objects. (Row-level
> > security predicate function returns empty string if
> > user issuing SQL is
> > owner of object).
>
>
>
>
>
>
>
> __________________________________________________________
> Find your next car at http://autos.yahoo.ca
>

--
Paul Baumgartel
paul.baumgartel_at_aya.yale.edu

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