This table contains column-level statistics for a single data file.

Column name	Column type
data_file_id	BIGINT
table_id	BIGINT
column_id	BIGINT
column_size_bytes	BIGINT
value_count	BIGINT
null_count	BIGINT
min_value	VARCHAR
max_value	VARCHAR
contains_nan	BOOLEAN
extra_stats	VARCHAR
min_is_exact	BOOLEAN
max_is_exact	BOOLEAN

• data_file_id refers to a data_file_id from the ducklake_data_file table.
• table_id refers to a table_id from the ducklake_table table.
• column_id refers to a column_id from the ducklake_column table.
• column_size_bytes is the byte size of the column.
• value_count is the number of non-NULL values in the column. This does not have to correspond to the number of records in the file for nested types.
• null_count is the number of values in the column that are NULL.
• min_value contains the minimum value for the column, encoded as a string. This does not have to be exact but has to be a lower bound. The value has to be decoded as the actual type for accurate comparison, e.g., on integer types.
• max_value contains the maximum value for the column, encoded as a string. This does not have to be exact but has to be an upper bound. The value has to be decoded as the actual type for accurate comparison, e.g., on integer types.
• contains_nan is a flag whether the column contains any NaN values. This is only relevant for floating-point types.
• extra_stats contains additional type-specific statistics, such as bounding box information for geometry types or shredded-field statistics for variant columns encoded as JSON.
• min_is_exact indicates whether min_value is exact rather than a conservative lower bound. NULL means that exactness is unknown.
• max_is_exact indicates whether max_value is exact rather than a conservative upper bound. NULL means that exactness is unknown.

The skip_stats_columns option suppresses min/max bounds for selected columns while retaining counts and sizes. Missing bounds cannot be used to exclude a file.