Math
DuckDB
LOG2
DuckDBMenghitung logaritma basis 2 dari sebuah angka. Berguna untuk perhitungan binary dan computer science.
Tipe hasil:
DOUBLEDiperbarui: 6 Jan 2026Syntax
SQL
LOG2(number)Parameter
numberDOUBLEwajib
Angka yang akan dihitung log2-nya (harus > 0)
Contoh Penggunaan
Logaritma Basis 2
SQL
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 );
Menghitung log2 dan jumlah bit yang dibutuhkan.
Hasil
| value | log2_val | bits_needed |
|---|---|---|
| 1 | 0 | 0 |
| 2 | 1 | 1 |
| 4 | 2 | 2 |
| 8 | 3 | 3 |
| ... 3 baris lainnya | ||
Binary Tree Depth
SQL
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 );
Menghitung kedalaman minimum binary tree untuk n nodes.
Hasil
| node_count | min_tree_depth |
|---|---|
| 1 | 1 |
| 3 | 2 |
| 7 | 3 |
| 15 | 4 |
| ... 2 baris lainnya | |
Storage Size Categories
SQL
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;
Mengkategorikan file berdasarkan ukuran menggunakan log2.
Hasil
| file_size_bytes | size_category |
|---|---|
| 500 | Bytes |
| 5000 | KB |
| 5000000 | MB |
| 5000000000 | GB |