While I was creating postgresql table partitions, I realized that I needed to move/copy the old id sequence to the new table. We can do this with the following query

copy_id_sequence.sql

postgres_test_db=# select last_value from old_table_id_seq;
 last_value 
------------
    2084740
(1 row)

postgres_test_db=# select last_value from new_table_id_seq;
 last_value 
------------
          1
(1 row)

-- In order to avoid errors, the id must be able to continue from where it left off. 
-- For this, we need to set the last value from the old sequence to the new one. 
-- We can get this id value in two different ways;

-- First one;
SELECT pg_catalog.setval(
  'new_table_id_seq', 
  (SELECT last_value FROM old_table_id_seq),
  true
);

-- Second one;
SELECT pg_catalog.setval(
  'new_table_id_seq',
  (SELECT max(id) FROM old_table),
  true
);

-- Technically they both do the same job but getting it directly from id_seq made more sense to me

-- After running setval we can verify that the old id is written to the new sequence;
postgres_test_db=# select last_value from new_table_id_seq;
 last_value 
------------
    2084740
(1 row)