\connect dblink_test_slave create table foo(f1 int, f2 text, f3 text[], primary key (f1,f2)); insert into foo values(0,'a','{"a0","b0","c0"}'); insert into foo values(1,'b','{"a1","b1","c1"}'); insert into foo values(2,'c','{"a2","b2","c2"}'); insert into foo values(3,'d','{"a3","b3","c3"}'); insert into foo values(4,'e','{"a4","b4","c4"}'); insert into foo values(5,'f','{"a5","b5","c5"}'); insert into foo values(6,'g','{"a6","b6","c6"}'); insert into foo values(7,'h','{"a7","b7","c7"}'); insert into foo values(8,'i','{"a8","b8","c8"}'); insert into foo values(9,'j','{"a9","b9","c9"}'); \connect dblink_test_master -- regular old dblink select * from dblink('dbname=dblink_test_slave','select * from foo') as t(a int, b text, c text[]) where t.a > 7; -- should generate "no connection available" error select * from dblink('select * from foo') as t(a int, b text, c text[]) where t.a > 7; -- create a persistent connection select dblink_connect('dbname=dblink_test_slave'); -- use the persistent connection select * from dblink('select * from foo') as t(a int, b text, c text[]) where t.a > 7; -- open a cursor select dblink_open('rmt_foo_cursor','select * from foo'); -- fetch some data select * from dblink_fetch('rmt_foo_cursor',4) as t(a int, b text, c text[]); select * from dblink_fetch('rmt_foo_cursor',4) as t(a int, b text, c text[]); -- this one only finds two rows left select * from dblink_fetch('rmt_foo_cursor',4) as t(a int, b text, c text[]); -- close the cursor select dblink_close('rmt_foo_cursor'); -- should generate "cursor rmt_foo_cursor does not exist" error select * from dblink_fetch('rmt_foo_cursor',4) as t(a int, b text, c text[]); -- close the persistent connection select dblink_disconnect(); -- should generate "no connection available" error select * from dblink('select * from foo') as t(a int, b text, c text[]) where t.a > 7; -- put more data into our slave table, first using arbitrary connection syntax -- but truncate the actual return value so we can use diff to check for success select substr(dblink_exec('dbname=dblink_test_slave','insert into foo values(10,''k'',''{"a10","b10","c10"}'')'),1,6); -- create a persistent connection select dblink_connect('dbname=dblink_test_slave'); -- put more data into our slave table, using persistent connection syntax -- but truncate the actual return value so we can use diff to check for success select substr(dblink_exec('insert into foo values(11,''l'',''{"a11","b11","c11"}'')'),1,6); -- let's see it select * from dblink('select * from foo') as t(a int, b text, c text[]); -- change some data select dblink_exec('update foo set f3[2] = ''b99'' where f1 = 11'); -- let's see it select * from dblink('select * from foo') as t(a int, b text, c text[]) where a = 11; -- delete some data select dblink_exec('delete from foo where f1 = 11'); -- let's see it select * from dblink('select * from foo') as t(a int, b text, c text[]) where a = 11; -- misc utilities \connect dblink_test_slave -- show the currently executing query select 'hello' as hello, dblink_current_query() as query; -- list the primary key fields select * from dblink_get_pkey('foo'); -- build an insert statement based on a local tuple, -- replacing the primary key values with new ones select dblink_build_sql_insert('foo','1 2',2,'{"0", "a"}','{"99", "xyz"}'); -- build an update statement based on a local tuple, -- replacing the primary key values with new ones select dblink_build_sql_update('foo','1 2',2,'{"0", "a"}','{"99", "xyz"}'); -- build a delete statement based on a local tuple, select dblink_build_sql_delete('foo','1 2',2,'{"0", "a"}');