private static double getAlpha(int precision, int m) {
    switch (precision) {
      case 4:
        return 0.673;
      case 5:
        return 0.697;
      case 6:
        return 0.709;
      default:
        return 0.7213 / (1 + 1.079 / m);
    }
  }
Constructs a HyperLogLog with the given precision.

<p>The precision parameter (4 <= precision <= 16)
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/operator/source/relational/aggregation/approximate/HyperLogLog.java