Re: Solving sudoku using SQL - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Solving sudoku using SQL
Date
Msg-id AANLkTi=KX-fh6n1hYdFO54ApGewSqGwftqSTdJe7OCa_@mail.gmail.com
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In response to Solving sudoku using SQL  (Tatsuo Ishii <ishii@postgresql.org>)
Responses Re: Solving sudoku using SQL  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Wed, Dec 8, 2010 at 8:57 AM, Tatsuo Ishii <ishii@postgresql.org> wrote:
> In the page first one takes infinite time by PostgreSQL 9.0.1.  Next
> one can be executed very quickly because the join order is explicitely
> specified by cross join syntax. This seems to be a limitation of
> PostgreSQL optimizer and I would like it be removed. Comments?

It's not easy to make the optimizer degrade gracefully when confronted
with a very large number of tables, but I agree it would be worthwhile
if we could figure out how to do it.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


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