foreign data wrapper caching mechanism support

Question

I want to use FDWs to access data from different data sources (CSV, SQL Server, Web Server) . I want to know if caching mechanism is supported for Foreign tables, so that when the connection is lost the data is still available?

Thanks.

Answer 1

example using MATERIALIZED VIEW

t=# create foreign table ft1 (pid int,state text) server past options (schema_name 'pg_catalog',table_name 'pg_stat_activity');
CREATE FOREIGN TABLE
Time: 1.771 ms
t=# create materialized view mv1 as select * FROM ft1 where state = 'active';
SELECT 8
Time: 275.935 ms
t=# select * from mv1;
  pid  | state
-------+--------
 15103 | active
 17699 | active
   795 | active
 17211 | active
  3434 | active
 20671 | active
 20888 | active
 27827 | active
(8 rows)

Time: 0.289 ms
t=# refresh materialized view mv1;
REFRESH MATERIALIZED VIEW
Time: 329.095 ms
t=# select * from mv1;
  pid  | state
-------+--------
 15103 | active
 17699 | active
   795 | active
 17211 | active
  3434 | active
 27396 | active
 27780 | active
 27803 | active
(8 rows)

Time: 0.401 ms