在单体到微服务迁移中如何重构关系数据库？

-----------+----------+-----------+---------------
 Instance  | Database | Schema    | Table
-----------+----------+-----------+---------------
 postgres1 | pagila   | common    | city
 postgres1 | pagila   | common    | country
-----------+----------+-----------+---------------
 postgres1 | pagila   | customers | address
 postgres1 | pagila   | customers | customer
-----------+----------+-----------+---------------
 postgres1 | pagila   | films     | actor
 postgres1 | pagila   | films     | category
 postgres1 | pagila   | films     | film
 postgres1 | pagila   | films     | film_actor
 postgres1 | pagila   | films     | film_category
 postgres1 | pagila   | films     | language
-----------+----------+-----------+---------------
 postgres1 | pagila   | sales     | payment
 postgres1 | pagila   | sales     | rental
-----------+----------+-----------+---------------
 postgres1 | pagila   | staff     | address
 postgres1 | pagila   | staff     | staff
-----------+----------+-----------+---------------
 postgres1 | pagila   | stores    | address
 postgres1 | pagila   | stores    | inventory
 postgres1 | pagila   | stores    | store

— wrap in transaction
BEGIN;

— create new customers.address table
CREATE SEQUENCE IF NOT EXISTS customers.address_address_id_seq
    INCREMENT 1
    START 1
    MINVALUE 1
    MAXVALUE 9223372036854775807
    CACHE 1;

ALTER SEQUENCE customers.address_address_id_seq
    OWNER TO pagila_admin;

CREATE TABLE IF NOT EXISTS customers.address (
    address_id integer DEFAULT nextval('address_address_id_seq'::regclass) NOT NULL PRIMARY KEY,
    address text NOT NULL,
    address2 text,
    district text NOT NULL,
    city_id smallint NOT NULL REFERENCES common.city ON UPDATE CASCADE ON DELETE RESTRICT,
    postal_code text,
    phone text NOT NULL,
    last_update timestamp with time zone DEFAULT now() NOT NULL
);

ALTER TABLE customers.address
    OWNER TO pagila_admin;

CREATE INDEX IF NOT EXISTS idx_fk_city_id ON customers.address(city_id);

CREATE TRIGGER last_updated
    BEFORE UPDATE ON customers.address FOR EACH ROW
    EXECUTE PROCEDURE last_updated();

COMMIT;

— wrap in transaction
BEGIN;

— copy only customer addresses to new customers.address table
INSERT INTO customers.address
SELECT *
FROM common.address
WHERE common.address.address_id IN (
        SELECT DISTINCT address_id
        FROM customers.customer
    );

— copy only staff addresses to new staff.address table
INSERT INTO staff.address
SELECT COUNT(*)
FROM common.address
WHERE common.address.address_id IN (
        SELECT DISTINCT address_id
        FROM staff.staff
    );

— copy only store addresses to new stores.address table
INSERT INTO stores.address
SELECT *
FROM common.address
WHERE common.address.address_id IN (
        SELECT DISTINCT address_id
        FROM stores.store
    );

— check for extraneous data in common.address before deleting
SELECT *
FROM common.address
WHERE common.address.address_id NOT IN
        (SELECT DISTINCT address_id FROM customers.customer)
    AND common.address.address_id NOT IN
        (SELECT DISTINCT address_id FROM staff.staff)
    AND common.address.address_id NOT IN
        (SELECT DISTINCT address_id FROM stores.store);
COMMIT;

— wrap in transaction
BEGIN;

— customers.customer
ALTER TABLE IF EXISTS customers.customer 
    DROP CONSTRAINT IF EXISTS customer_address_id_fkey;

ALTER TABLE IF EXISTS customers.customer
    ADD CONSTRAINT customer_address_id_fkey FOREIGN KEY (address_id)
    REFERENCES customers.address (address_id) MATCH SIMPLE
    ON UPDATE CASCADE
    ON DELETE RESTRICT;

COMMIT;

# dump v2 of pagila database
pg_dump -Fc -d pagila_v2 -f pagila_v2.dump

# create 2 new v3 databases
export PGDATABASE="postgres"
psql << EOF
\x
CREATE DATABASE pagila_v3;
CREATE DATABASE products_v3;
EOF

# restore v2 of pagila database
pg_restore -d pagila_v3 pagila_v2.dump
pg_restore -d products_v3 -n films pagila_v2.dump

# connect to new pagila database
export PGDATABASE="pagila_v3"
psql