PostgreSQL sharding example

to start

rename .env_example to .env
docker compose up 

to insert test data

INSERT INTO books (id, category_id, author, title, year)
VALUES (1, 1, 'Author1', 'book1', 1980),
       (2, 2, 'Author2', 'book2', 1997),
       (3, 5, 'Author3', 'book3', 2005),
       (4, 2, 'Author4', 'book4', 2005),
       (5, 7, 'Author5', 'book5', 2005),
       (6, 5, 'Author6', 'book6', 2001),
       (7, 9, 'Author7', 'book7', 1917),
       (8, 2, 'Author8', 'book8', 1956),
       (9, 1, 'Author9', 'book9', 1972),
       (10, 8, 'Author10', 'book10', 1993);