foreign_counts.sql

CREATE VIEW salesforce.actual_sf_task_count AS
    SELECT COUNT(*) sf_task_count
    FROM salesforce.sf_task;

-- [local]:5432 salesforce@salesforce # SELECT * FROM actual_sf_task_count;
-- +---------------+
-- | sf_task_count |
-- +---------------+
-- |       8226055 |
-- +---------------+
-- (1 row)

-- Time: 2508.322 ms

CREATE VIEW salesforce.estimated_sf_task_count AS
    SELECT reltuples::integer AS sf_task_count
    FROM pg_class
    WHERE oid = 'salesforce.sf_task'::regclass;

-- [local]:5432 salesforce@salesforce # SELECT * FROM estimated_sf_task_count;
-- +---------------+
-- | sf_task_count |
-- +---------------+
-- |       8226055 |
-- +---------------+
-- (1 row)

-- Time: 0.465 ms

CREATE FOREIGN TABLE slush.fdw_actual_sf_task_count (
    sf_task_count INTEGER
)
SERVER salesforce OPTIONS (
    schema_name 'salesforce',
    table_name 'actual_sf_task_count'
);

-- [local]:5432 slush@slush # EXPLAIN VERBOSE SELECT * FROM slush.fdw_actual_sf_task_count;
-- +--------------------------------------------------------------------------------------------+
-- |                                         QUERY PLAN                                         |
-- +--------------------------------------------------------------------------------------------+
-- | Foreign Scan on slush.fdw_actual_sf_task_count  (cost=351767.69..351767.72 rows=1 width=0) |
-- |   Output: sf_task_count                                                                    |
-- |   Remote SQL: SELECT sf_task_count FROM salesforce.actual_sf_task_count                    |
-- +--------------------------------------------------------------------------------------------+
-- (3 rows)

-- Time: 7.936 ms

CREATE FOREIGN TABLE slush.fdw_estimated_sf_task_count (
    sf_task_count INTEGER
)
SERVER salesforce OPTIONS (
    schema_name 'salesforce',
    table_name 'estimated_sf_task_count'
);

-- [local]:5432 slush@slush # EXPLAIN VERBOSE SELECT * FROM slush.fdw_estimated_sf_task_count;
-- +-----------------------------------------------------------------------------------------+
-- |                                       QUERY PLAN                                        |
-- +-----------------------------------------------------------------------------------------+
-- | Foreign Scan on slush.fdw_estimated_sf_task_count  (cost=100.27..108.31 rows=1 width=4) |
-- |   Output: sf_task_count                                                                 |
-- |   Remote SQL: SELECT sf_task_count FROM salesforce.estimated_sf_task_count              |
-- +-----------------------------------------------------------------------------------------+
-- (3 rows)

-- Time: 1.591 ms

SELECT COUNT(*)
FROM salesforce.sf_task;

-- [local]:5432 slush@slush # SELECT COUNT(*)
-- slush-# FROM salesforce.sf_task;
-- +---------+
-- |  count  |
-- +---------+
-- | 8226055 |
-- +---------+
-- (1 row)

-- Time: 11673.777 ms