Re: PostgreSQL does CAST implicitely between int and adomain derived from int

От: Kevin Grittner
Тема: Re: PostgreSQL does CAST implicitely between int and adomain derived from int
Дата: ,
Msg-id: 4A964EE1020000250002A3E8@gw.wicourts.gov
(см: обсуждение, исходный текст)
Ответ на: Re: PostgreSQL does CAST implicitely between int and a domain derived from int  (Jean-Michel Pouré)
Ответы: Re: PostgreSQL does CAST implicitely between int and adomain derived from int  (Jean-Michel Pouré)
Список: pgsql-performance

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Re: PostgreSQL does CAST implicitely between int and a domain derived from int  ("Kevin Grittner", )
 Re: PostgreSQL does CAST implicitely between int and a domain derived from int  ("Kevin Grittner", )
  Re: PostgreSQL does CAST implicitely between int and a domain derived from int  (Jean-Michel Pouré, )
   Re: PostgreSQL does CAST implicitely between int and adomain derived from int  ("Kevin Grittner", )
    Re: PostgreSQL does CAST implicitely between int and adomain derived from int  (Jean-Michel Pouré, )
     Re: PostgreSQL does CAST implicitely between int andadomain derived from int  ("Kevin Grittner", )
      Re: PostgreSQL does CAST implicitely between int andadomain derived from int  (Jean-Michel Pouré, )
       Re: PostgreSQL does CAST implicitely between int and a domain derived from int  ("Kevin Grittner", )
        Re: PostgreSQL  (Jean-Michel Pouré, )
        Re: PostgreSQL does CAST implicitely between int and a domain derived from int  (Robert Haas, )
         Re: PostgreSQL does CAST implicitely between int and a domain derived from int  (Tom Lane, )
          Re: PostgreSQL does CAST implicitely between int and a domain derived from int  (Jean-Michel Pouré, )
           Re: PostgreSQL does CAST implicitely between int and a domain derived from int  (Bruce Momjian, )
            Re: PostgreSQL does CAST implicitely between int and a domain derived from int  (Jean-Michel Pouré, )
             Re: PostgreSQL does CAST implicitely between int and a domain derived from int  (Tom Lane, )
              Re: PostgreSQL does CAST implicitely between int and a domain derived from int  (Jean-Michel Pouré, )
               Re: PostgreSQL does CAST implicitely between int and a domain derived from int  (Tom Lane, )
                Re: PostgreSQL does CAST implicitely between int and a domain derived from int  (Greg Stark, )
         Re: PostgreSQL does CAST implicitely between int and a domain derived from int  (Jean-Michel Pouré, )
 Re: PostgreSQL does CAST implicitely between int and a domain derived from int  (Jean-Michel Pouré, )
  Re: PostgreSQL does CAST implicitely between int and adomain derived from int  ("Kevin Grittner", )
   Re: PostgreSQL does CAST implicitely between int and adomain derived from int  (Jean-Michel Pouré, )

>Jean-Michel Pouré<> wrote:
> Does not show any result because of ROLLBACK;

Then you need to use a better tool to run it.  For example, in psql:

test=# create table t2 (c1 int not null);
CREATE TABLE
test=# insert into t2 select * from generate_series(1,10000);
INSERT 0 10000
test=# create unique index t2_c1 on t2 (c1);
CREATE INDEX
test=# explain analyze select count(*) from t2 where c1 between 200 and
400;
                                                      QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=47.77..47.78 rows=1 width=0) (actual
time=0.668..0.669 rows=1 loops=1)
   ->  Bitmap Heap Scan on t2  (cost=4.76..47.64 rows=50 width=0)
(actual time=0.091..0.380 rows=201 loops=1)
         Recheck Cond: ((c1 >= 200) AND (c1 <= 400))
         ->  Bitmap Index Scan on t2_c1  (cost=0.00..4.75 rows=50
width=0) (actual time=0.080..0.080 rows=201 loops=1)
               Index Cond: ((c1 >= 200) AND (c1 <= 400))
 Total runtime: 0.722 ms
(6 rows)

test=# begin transaction;
BEGIN
test=# drop index t2_c1;
DROP INDEX
test=# explain analyze select count(*) from t2 where c1 between 200 and
400;
                                               QUERY PLAN
--------------------------------------------------------------------------------------------------------
 Aggregate  (cost=190.50..190.51 rows=1 width=0) (actual
time=3.324..3.325 rows=1 loops=1)
   ->  Seq Scan on t2  (cost=0.00..190.00 rows=200 width=0) (actual
time=0.053..3.036 rows=201 loops=1)
         Filter: ((c1 >= 200) AND (c1 <= 400))
 Total runtime: 3.366 ms
(4 rows)

test=# rollback transaction;
ROLLBACK

-Kevin


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