private void grow(long length) {
    // how many segments are required to get to the length?
    int requiredSegments = segment(length) + 1;

    // grow base array if necessary
    if (array.length < requiredSegments) {
      array = Arrays.copyOf(array, requiredSegments);
    }

    // add new segments
    while (segments < requiredSegments) {
      allocateNewSegment();
    }
  }
Fills the entire big array with the specified value.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/operator/source/relational/aggregation/grouped/array/LongBigArray.java