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From: Mladen Gogala <gogala.mladen@gmail.com>
Newsgroups: comp.databases.postgresql
Subject: Re: Case-insensitive select
Date: Mon, 5 Sep 2011 10:53:28 +0000 (UTC)
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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? 



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