Groups > comp.databases.postgresql > #232

Re: Case-insensitive select

From	Mladen Gogala <gogala.mladen@gmail.com>
Newsgroups	comp.databases.postgresql
Subject	Re: Case-insensitive select
Date	2011-09-05 10:53 +0000
Organization	solani.org
Message-ID	<pan.2011.09.05.10.53.26@gmail.com> (permalink)
References	(5 earlier) <1314888079.999065@proxy.dienste.wien.at> <pan.2011.09.01.21.26.13@gmail.com> <1314950920.382293@proxy.dienste.wien.at> <pan.2011.09.02.13.03.56@gmail.com> <1315208734.245902@proxy.dienste.wien.at>

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On Mon, 05 Sep 2011 09:45:13 +0200, Laurenz Albe wrote:

> 
> Why do you claim that without a test? This is PostgreSQL 9.1:
> 
> CREATE TABLE test(id serial primary key, val varchar(20) NOT NULL);
> 
> DO $$BEGIN
>    FOR i IN 1..10000 LOOP
>       INSERT INTO test(val) VALUES (substr(random()::text, 3));
>    END LOOP;
> END;$$;
> 
> CREATE INDEX test_val_ind ON test(lower(val));
> 
> SHOW default_statistics_target;
> 
>  default_statistics_target
> ---------------------------
>  100
> (1 row)
> 
> ANALYZE test;
> 
> SELECT array_length(histogram_bounds, 1) FROM pg_stats
>    WHERE tablename = 'test_val_ind';
> 
>  array_length
> --------------
>           101
> (1 row)
> 
> Yours,
> Laurenz Albe

I don't understand? What does this prove? That there is a histogram on 
lower(val)? How does your example prove that? 



-- 
http://mgogala.byethost5.com

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Thread

Case-insensitive select RVince <rvince99@gmail.com> - 2011-08-31 05:29 -0700
  Re: Case-insensitive select Mladen Gogala <gogala.mladen@gmail.com> - 2011-08-31 13:19 +0000
  Re: Case-insensitive select Matthew Woodcraft <mattheww@chiark.greenend.org.uk> - 2011-08-31 20:42 +0100
    Re: Case-insensitive select Mladen Gogala <gogala.mladen@gmail.com> - 2011-08-31 23:00 +0000
      Re: Case-insensitive select "Laurenz Albe" <invite@spam.to.invalid> - 2011-09-01 08:56 +0200
        Re: Case-insensitive select Mladen Gogala <gogala.mladen@gmail.com> - 2011-09-01 12:57 +0000
          Re: Case-insensitive select "Laurenz Albe" <invite@spam.to.invalid> - 2011-09-01 16:40 +0200
            Re: Case-insensitive select Mladen Gogala <gogala.mladen@gmail.com> - 2011-09-01 21:26 +0000
              Re: Case-insensitive select "Laurenz Albe" <invite@spam.to.invalid> - 2011-09-02 10:08 +0200
                Re: Case-insensitive select Mladen Gogala <gogala.mladen@gmail.com> - 2011-09-02 13:03 +0000
                Re: Case-insensitive select "Laurenz Albe" <invite@spam.to.invalid> - 2011-09-05 09:45 +0200
                Re: Case-insensitive select Mladen Gogala <gogala.mladen@gmail.com> - 2011-09-05 10:53 +0000
                Re: Case-insensitive select "Laurenz Albe" <invite@spam.to.invalid> - 2011-09-05 16:13 +0200
                Re: Case-insensitive select Mladen Gogala <gogala.mladen@gmail.com> - 2011-09-06 02:21 +0000
              Re: Case-insensitive select "Laurenz Albe" <invite@spam.to.invalid> - 2011-09-02 10:08 +0200

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