On Tue, Dec 13, 2011 at 1:57 PM, Tom Lane wrote:
> Jon Nelson writes:
>> I've got a 5GB table with about 12 million rows.
>> Recently, I had to select the distinct values from just one column.
>> The planner chose an index scan. The query took almost an hour.
>> When I forced index scan off, the
Jon Nelson writes:
> I've got a 5GB table with about 12 million rows.
> Recently, I had to select the distinct values from just one column.
> The planner chose an index scan. The query took almost an hour.
> When I forced index scan off, the query took 90 seconds (full table scan).
Usually, we he
I've got a 5GB table with about 12 million rows.
Recently, I had to select the distinct values from just one column.
The planner chose an index scan. The query took almost an hour.
When I forced index scan off, the query took 90 seconds (full table scan).
The planner estimated 70,000 unique values
