PostgreSQL

create database

    CREATE DATABASE "name" ENCODING 'UTF8' LC_COLLATE 'ru_UA.UTF-8' LC_CTYPE 'ru_UA.UTF-8' TEMPLATE template0;

unix timestamp with microseconds

    "unix_timestamp" FLOAT NOT NULL DEFAULT EXTRACT(EPOCH FROM CURRENT_TIMESTAMP),

uuid

https://www.postgresql.org/docs/current/static/uuid-ossp.html

    CREATE EXTENSION IF NOT EXISTS "uuid-ossp";

    # use UUID v1 - based on MAC addr.
    "id" UUID PRIMARY KEY NOT NULL DEFAULT uuid_generate_v1()

    CREATE EXTENSION IF NOT EXISTS "pgcrypto";

    # use UUID v4 - random
    "id" UUID PRIMARY KEY NOT NULL DEFAULT gen_random_uuid()