LOG2

1
SELECT
2
  value,
3
  LOG2(value) as log2_val,
4
  FLOOR(LOG2(value)) as bits_needed
5
FROM (
6
  SELECT unnest([1, 2, 4, 8, 16, 100, 1000]) as value
7
);

1
SELECT
2
  node_count,
3
  CEILING(LOG2(node_count + 1)) as min_tree_depth
4
FROM (
5
  SELECT unnest([1, 3, 7, 15, 31, 100]) as node_count
6
);

1
SELECT
2
  file_size_bytes,
3
  CASE FLOOR(LOG2(file_size_bytes) / 10)
4
    WHEN 0 THEN 'Bytes'
5
    WHEN 1 THEN 'KB'
6
    WHEN 2 THEN 'MB'
7
    WHEN 3 THEN 'GB'
8
    ELSE 'TB+'
9
  END as size_category
10
FROM files;