I was implementing the infinity time constants in DuckDB when I ran into an infinite loop. It seems that PG has the same problem for the same reason (adding an interval to an infinite timestamp produces the same timestamp, so the increment operation never goes anywhere.) Here is the query:
selectCOUNT(*)
FROM generate_series('-infinity'::TIMESTAMP, 'epoch'::TIMESTAMP, INTERVAL'1 DAY');
This seems like a DoS great attack, so we are disallowing infinities as bounds for both table and scalar series generation. As an upper bound, it eventually gives an error, so it seems there is not much utility anyway.
There are more ways to achieve the same effect. The protection is safe setting of temp_file_limit
2022-04-20 09:59:54) postgres=# set temp_file_limit to '1MB'; SET (2022-04-20 18:51:48) postgres=# select COUNT(*) FROM generate_series('-infinity'::TIMESTAMP, 'epoch'::TIMESTAMP, INTERVAL '1 DAY'); ERROR: temporary file size exceeds temp_file_limit (1024kB) (2022-04-20 18:51:50) postgres=#
Regards
Pavel
Met vriendelijke groet, best regards, mit freundlichen Grüßen,