Thiết Kế Dashboard Grafana Cho TimescaleDB Không Gây Quá Tải CPU

-- Automatically route Grafana queries by selected zoom span
WITH params AS (
  SELECT ($__timeTo()::timestamptz - $__timeFrom()::timestamptz) AS span
)
SELECT bucket AS "time", close AS "value", volume
FROM ohlcv_1m, params
WHERE params.span <= INTERVAL '14 days'
  AND symbol_id = $symbol_id
  AND bucket BETWEEN $__timeFrom() AND $__timeTo()
UNION ALL
SELECT bucket AS "time", close AS "value", volume
FROM ohlcv_1h, params
WHERE params.span > INTERVAL '14 days'
  AND symbol_id = $symbol_id
  AND bucket BETWEEN $__timeFrom() AND $__timeTo()
ORDER BY 1 ASC;