Postgres 15

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

select version();

version

PostgreSQL 15beta3 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-10), 64-bit

SELECT 1

CREATE TABLE foo (
    id INT PRIMARY KEY GENERATED ALWAYS AS IDENTITY,
    name TEXT DEFAULT md5(random()::text)
);

CREATE TABLE

MERGE INTO
  foo AS tgt
USING
  generate_series(1, 10) AS src  -- << use your source row set here
ON
  FALSE
WHEN NOT MATCHED THEN
  INSERT DEFAULT VALUES
;

MERGE 10

select * from foo ;

id
name

1
87eea996b7a6d15df944840535f3cf49

2
38d4907bfaf87a538e1de05188579f64

3
b084842a4fef68a58b0218ed3d460229

4
406692360ada3ee7b83d049477fc20fc

5
758a411fe8474fbba0b9e74a2c276fb1

6
9043ece40bb0b19ba37047de9923b227

7
b5154cc83185fa636437191408ff50f4

8
5047bb2693b750dbef14e5a7022cf4a0

9
f8b002b82ac97e5808e8b57b5ca8f838

10
09c7995d0d3993b814fe205c87295031

SELECT 10

id	name
1	87eea996b7a6d15df944840535f3cf49
2	38d4907bfaf87a538e1de05188579f64
3	b084842a4fef68a58b0218ed3d460229
4	406692360ada3ee7b83d049477fc20fc
5	758a411fe8474fbba0b9e74a2c276fb1
6	9043ece40bb0b19ba37047de9923b227
7	b5154cc83185fa636437191408ff50f4
8	5047bb2693b750dbef14e5a7022cf4a0
9	f8b002b82ac97e5808e8b57b5ca8f838
10	09c7995d0d3993b814fe205c87295031