Hi! Are you trying to fix any real problem? So, do you have any reproduces where dblink stucks while processing tuples? I am somehow surprised if we do not have CFI somewhere inside tuplestore_puttuple...
This can be reproduced when iteration over millions of tuples, particularly when the tuples spill to a temp file on disk.
I added pg_usleep(1000L) before the end of the loop to have a predictable repro, which looks like no CFI in tuplestore_puttuple.
Tested with the below queries to verify the behavior (which should trigger temp IO).
SET work_mem = '64kB'; SELECT dblink_connect('myconn', 'dbname=' || current_database()); SELECT dblink_open('myconn', 'mycursor', 'SELECT i, repeat(''x'', 1024) FROM generate_series(1, 100000) i'); explain analyze SELECT * FROM dblink_fetch('myconn', 'mycursor', 100000) AS t(i int, pad text); SELECT dblink_close('myconn', 'mycursor'); SELECT dblink_disconnect('myconn'); RESET work_mem;
