multicolumn partitioning help

[James Robertson <james@xxxxxxxxxxxxxxx>]

Hey folks,

I am having issues with multicolumn partitioning. For reference I am using the following link as my guide:
https://www.postgresql.org/docs/devel/sql-createtable.html

To demonstrate my problem, I created a simple table called humans. I want to partition by the year of the human birth and then the first character of the hash. So for each year I'll have year*16 partitions. (hex)

CREATE TABLE humans (
    hash bytea,
    fname text,
    dob date
    )PARTITION BY RANGE (EXTRACT(YEAR FROM dob),substring(hash::text, 1, 1));
   
Reading the documentation:   "When creating a range partition, the lower bound specified with FROM is an inclusive bound, whereas the upper bound specified with TO is an exclusive bound".

However I can't insert any of the following after the first one, because it says it overlaps. Do I need to do anything different when defining multi-column partitions?

This works:
CREATE TABLE humans_1968_0 PARTITION OF humans FOR VALUES FROM (1968, '0') TO (1969, '1');


These fail: 
CREATE TABLE humans_1968_1 PARTITION OF humans FOR VALUES FROM (1968, '1') TO (1969, '2');
CREATE TABLE humans_1968_2 PARTITION OF humans FOR VALUES FROM (1968, '2') TO (1969, '3');
CREATE TABLE humans_1968_3 PARTITION OF humans FOR VALUES FROM (1968, '3') TO (1969, '4');
CREATE TABLE humans_1968_4 PARTITION OF humans FOR VALUES FROM (1968, '4') TO (1969, '5');
CREATE TABLE humans_1968_5 PARTITION OF humans FOR VALUES FROM (1968, '5') TO (1969, '6');
CREATE TABLE humans_1968_6 PARTITION OF humans FOR VALUES FROM (1968, '6') TO (1969, '7');
CREATE TABLE humans_1968_7 PARTITION OF humans FOR VALUES FROM (1968, '7') TO (1969, '8');
CREATE TABLE humans_1968_8 PARTITION OF humans FOR VALUES FROM (1968, '8') TO (1969, '9');
CREATE TABLE humans_1968_9 PARTITION OF humans FOR VALUES FROM (1968, '9') TO (1969, 'a');
CREATE TABLE humans_1968_a PARTITION OF humans FOR VALUES FROM (1968, 'a') TO (1969, 'b');
CREATE TABLE humans_1968_b PARTITION OF humans FOR VALUES FROM (1968, 'b') TO (1969, 'c');
CREATE TABLE humans_1968_c PARTITION OF humans FOR VALUES FROM (1968, 'c') TO (1969, 'd');
CREATE TABLE humans_1968_d PARTITION OF humans FOR VALUES FROM (1968, 'd') TO (1969, 'e');
CREATE TABLE humans_1968_e PARTITION OF humans FOR VALUES FROM (1968, 'e') TO (1969, 'f');
CREATE TABLE humans_1968_f PARTITION OF humans FOR VALUES FROM (1968, 'f') TO (1969, 'g');
CREATE TABLE humans_1969_0 PARTITION OF humans FOR VALUES FROM (1969, '0') TO (1970, '1');
CREATE TABLE humans_1969_1 PARTITION OF humans FOR VALUES FROM (1969, '1') TO (1970, '2');
CREATE TABLE humans_1969_2 PARTITION OF humans FOR VALUES FROM (1969, '2') TO (1970, '3');
CREATE TABLE humans_1969_3 PARTITION OF humans FOR VALUES FROM (1969, '3') TO (1970, '4');
CREATE TABLE humans_1969_4 PARTITION OF humans FOR VALUES FROM (1969, '4') TO (1970, '5');
CREATE TABLE humans_1969_5 PARTITION OF humans FOR VALUES FROM (1969, '5') TO (1970, '6');
CREATE TABLE humans_1969_6 PARTITION OF humans FOR VALUES FROM (1969, '6') TO (1970, '7');
CREATE TABLE humans_1969_7 PARTITION OF humans FOR VALUES FROM (1969, '7') TO (1970, '8');
CREATE TABLE humans_1969_8 PARTITION OF humans FOR VALUES FROM (1969, '8') TO (1970, '9');
CREATE TABLE humans_1969_9 PARTITION OF humans FOR VALUES FROM (1969, '9') TO (1970, 'a');
CREATE TABLE humans_1969_a PARTITION OF humans FOR VALUES FROM (1969, 'a') TO (1970, 'b');
CREATE TABLE humans_1969_b PARTITION OF humans FOR VALUES FROM (1969, 'b') TO (1970, 'c');
CREATE TABLE humans_1969_c PARTITION OF humans FOR VALUES FROM (1969, 'c') TO (1970, 'd');
CREATE TABLE humans_1969_d PARTITION OF humans FOR VALUES FROM (1969, 'd') TO (1970, 'e');
CREATE TABLE humans_1969_e PARTITION OF humans FOR VALUES FROM (1969, 'e') TO (1970, 'f');
CREATE TABLE humans_1969_f PARTITION OF humans FOR VALUES FROM (1969, 'f') TO (1970, 'g');

Thank you for reviewing this problem.