CREATE TABLE IF NOT EXISTS data_quality_stats (
    customer_id UUID PRIMARY KEY,
    table_name TEXT NOT NULL,
    row_count BIGINT NOT NULL DEFAULT 0,
    drift_score FLOAT NOT NULL DEFAULT 0.0,
    last_sync_at TIMESTAMPTZ,
    last_error TEXT,
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_dqs_customer ON data_quality_stats(customer_id);
CREATE INDEX IF NOT EXISTS idx_dqs_table ON data_quality_stats(customer_id, table_name);