Re: FailedAssertion() in 8.2beta1 - Mailing list pgsql-hackers

From Sergey E. Koposov
Subject Re: FailedAssertion() in 8.2beta1
Date
Msg-id Pine.LNX.4.64.0610072031330.1513@lnfm1.sai.msu.ru
Whole thread Raw
In response to Re: FailedAssertion() in 8.2beta1  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: FailedAssertion() in 8.2beta1  ("Sergey E. Koposov" <math@sai.msu.ru>)
Re: FailedAssertion() in 8.2beta1  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Sat, 7 Oct 2006, Tom Lane wrote:

> "Sergey E. Koposov" <math@sai.msu.ru> writes:
>> I've found a bug with 8.2beta1:
>
> Can you put together a self-contained test case for this?  The planner

I'll try, but it will be quite hard.

> is evidently generating an incorrect plan from that messy view, but
> trying to reverse-engineer the complete scenario from what you've told
> us looks painful.  (No, I don't think the log setting is related.)
>

At least the plan for the problematic query looks like this

cas=# explain UPDATE table_list SET description = 'tag{image SRC="/vizier/new2.gif"}3rd release of DENIS (2005Sep)'
WHERE id = cas_get_table_id ('cas_data_sega','b_denis_denis5' );
QUERY PLAN 
 

----------------------------------------------------------------------------------------------------------------------------
NestedLoop  (cost=0.01..17.11 rows=2 width=82)   ->  Index Scan using table_user_list_pkey on table_user_list
(cost=0.00..8.02rows=1 width=10)         Index Cond: (cas_get_table_id('cas_data_sega'::character varying,
'b_denis_denis5'::charactervarying) = id)   ->  Append  (cost=0.00..9.07 rows=2 width=76)         ->  Index Scan using
table_user_list_pkeyon table_user_list  (cost=0.00..8.02 rows=1 width=76)               Index Cond: (id =
cas_get_table_id('cas_data_sega'::charactervarying, 'b_denis_denis5'::character varying))         ->  Seq Scan on
table_list (cost=0.00..1.04 rows=1 width=51)               Filter: (id = cas_get_table_id('cas_data_sega'::character
varying,'b_denis_denis5'::character varying))
 
(8 rows)

As I see from it, it generates two seq. scans for one table (table_user_list)

Will it be enough to provide the testcase for just that 'expain UPDATE' ?

Regards,    Sergey

*******************************************************************
Sergey E. Koposov
Max Planck Institute for Astronomy/Sternberg Astronomical Institute
Tel: +49-6221-528-349
Web: http://lnfm1.sai.msu.ru/~math
E-mail: math@sai.msu.ru


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