Re: Question about difference in performance of 2 queries

Here is the pg_stats data. The explain analyze queries are still running.

select * from pg_stats where tablename = 'f_pageviews' and attname =
'date_key';
schemaname | tablename | attname | null_frac | avg_width |
n_distinct | most_common_vals
|
most_common_freqs
| histogram_bounds | correlation
------------+-------------+----------+-----------+-----------+------------+-------------------------------------------+---------------------------------------------------------------------------------------------------+-----------------------------------------------+-------------
public | f_pageviews | date_key | 0 | 4 |
60 | {335,307,309,336,308,321,314,342,322,316} |
{0.0283333,0.0243333,0.0243333,0.0243333,0.024,0.0233333,0.0226667,0.0226667,0.0223333,0.0216667}
| {304,311,318,325,329,334,341,346,351,356,363} | 0.345026
(1 row)

select * from pg_stats where tablename = 'f_pageviews' and attname =
'content_key';
schemaname | tablename | attname | null_frac | avg_width |
n_distinct | most_common_vals | most_common_freqs
|
histogram_bounds | correlation
------------+-------------+-------------+-----------+-----------+------------+------------------+-----------------------+-------------------------------------------------------------------------------------+-------------
public | f_pageviews | content_key | 0 | 4 |
983 | {-1,1528483} | {0.749333,0.00166667} |
{38966,323835,590676,717061,919148,1091875,1208244,1299702,1375366,1434079,1528910}
| 0.103399
(1 row)

Thanks.

--sean

Tom Lane wrote:

>Please show EXPLAIN ANALYZE output for your queries, not just EXPLAIN.
>Also it would be useful to see the pg_stats rows for the date_key and
>content_key columns.
>
> regards, tom lane
>
>
>