From: | Andrew Gierth <andrew(at)tao11(dot)riddles(dot)org(dot)uk> |
---|---|
To: | Alexander Korotkov <aekorotkov(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Fix picksplit with nan values |
Date: | 2013-09-16 12:13:27 |
Message-ID: | 87txhl6kc9.fsf@news-spur.riddles.org.uk |
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Thread: | |
Lists: | pgsql-hackers |
>>>>> "Alexander" == Alexander Korotkov <aekorotkov(at)gmail(dot)com> writes:
Alexander> 2) NaN coordinates should be processed in GiST index scan
Alexander> like in sequential scan.
postgres=# select * from pts order by a <-> '(0,0)' limit 10;
a
----------
(1,1)
(7,nan)
(9,nan)
(11,nan)
(4,nan)
(nan,6)
(2,1)
(1,2)
(2,2)
(3,1)
(10 rows)
postgres=# set enable_indexscan=false;
SET
postgres=# select * from pts order by a <-> '(0,0)' limit 10;
a
-------
(1,1)
(2,1)
(1,2)
(2,2)
(3,1)
(1,3)
(3,2)
(2,3)
(4,1)
(1,4)
(10 rows)
this data set was created by:
insert into pts
select point(i,j)
from (select generate_series(1,100)::float8 union all select 'nan') s1(i),
(select generate_series(1,100)::float8 union all select 'nan') s2(j)
order by random();
--
Andrew (irc:RhodiumToad)
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