Using B-Tree index for such kind of queries (with '>','<')

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От	Andrzej Zeja
Тема	Using B-Tree index for such kind of queries (with '>','<')
Дата	6 мая 2002 г. 12:52:25
Msg-id	002101c1f503$64ac6050$95d1a4c3@tu.kielce.pl обсуждение исходный текст
Список	pgsql-cygwin

I've got table Test and index for this table B-Tree type.

and

I've made query like:

Select * from test where Id<100;

During execution Optimizer makes no use of the index.

In documentation stands that using B-Tree index is used for such kind of queries (with '>','<').

Everything works fine only for '=' comparision.

Why it doesn't work in my case?

Why Sequenced Scan is executed instead of indexed scan?

Below is output of my query:

template1=# explain select * from test where id > 100;
NOTICE: QUERY PLAN:

Seq Scan on test (cost=0.00..1.06 rows=3 width=18)

NOTICE: QUERY PLAN:

Seq Scan on test (cost=0.00..1.06 rows=3 width=18)

Andrzej

В списке pgsql-cygwin по дате отправления:

От: Liviu Taloi
Дата: 06 мая 2002 г., 08:46:03
Сообщение: The service did not respond to the start..

От: "Henshall, Stuart - WCP"
Дата: 08 мая 2002 г., 08:06:08
Сообщение: Re: Using B-Tree index for such kind of queries (with '