Thread: Btree doesn't work with ">" condition

Hi,   I'm testing PostgreSQL, version 7.1.2, and I create a table,  test1, with these kind of fields:

CREATE TABLE test1 (   id integer,   content varchar
);

with 800.000 records, and a btree index setted on the id field.

I noticed the query uses the index for "=" and "<" operators, but if the value used for the "<" operator is higher
(600.000for example), the query makes a seq scan of the table, and the index never works with the ">" operator. Am I
managingthe indexes well ?
 

Thanks for the help.

Ciao Paolo





Paolo Cassago

TalentManager
Milan, Paris, Madrid

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Paolo Cassago wrote:

>Hi,
>    I'm testing PostgreSQL, version 7.1.2, and I create a table,  test1, with these kind of fields:
>
>CREATE TABLE test1 (
>    id integer,
>    content varchar
>);
>
>with 800.000 records, and a btree index setted on the id field.
>
>I noticed the query uses the index for "=" and "<" operators, but if the value used for the "<" operator is higher
(600.000for example), the query makes a seq scan of the table, and the index never works with the ">" operator. Am I
managingthe indexes well ?
 
>
Have you run VACUUM ANALYZE lately ?

What does EXPLAIN think of the costs ?

-------------
Hannu