Configuration
Block Sizes
When persisting a database to disk, DuckDB writes to a dedicated file containing a list of blocks holding the data.
In the case of a file that only holds very little data, e.g., a small table, the default block size of 256KB might not be ideal.
Therefore, DuckDB's storage format supports different block sizes.  
There are a few constraints on possible block size values.  
* Must be a power of two.
* Must be greater or equal to 16384 (16 KB).
* Must be lesser or equal to 262144 (256 KB).  
You can set the default block size for all new DuckDB files created by an instance like so:  
```sql
SET default_block_size = '16384';
```  
It is also possible to set the block size on a per-file basis, see [`ATTACH`](#docs:sql:statements:attach) for details.