Re: [ADMIN] Why my index does not increase performance?

> Hi, All!
>
> My database has a big table (more 1 million records) that contains
> a date field. This field has approximately 150 unique values (dates
> of five monthes) per table. I created index as follow:
>
>     create index mytable_ind on mytable (mydate date_ops);
>
> Next, I perform following query:
>
>     select max(mydate) from mytable;
>
> And time length of this query is about 100 seconds! I think postgres
> looks up ALL records in the table to find max value and does not use
> created index. Why? Database is vacuumed, PostgreSQL 6.3.2 on Solaris
> 2.5.1/x86, CPU P166, RAM 64 Mb.

It is on our TODO list.

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