orderTable

CREATE TABLE IF NOT EXISTS orderTable
(
    order_id        SERIAL          PRIMARY KEY,
    order_name      TEXT            NOT NULL,
    product_id      SERIAL          REFERENCES productTable (product_id),
    begin_timestamp TIMESTAMPTZ,
    end_timestamp   TIMESTAMPTZ,
    target_units    INTEGER,
    asset_id        SERIAL          REFERENCES assetTable (id),
    unique (asset_id, order_name),
    CHECK (begin_timestamp < end_timestamp),
    CHECK (target_units > 0),
    EXCLUDE USING gist (asset_id WITH =, tstzrange(begin_timestamp, end_timestamp) WITH &&) WHERE (begin_timestamp IS NOT NULL AND end_timestamp IS NOT NULL)
);