Struct WriteOptions 

pub struct WriteOptions {
    pub mode: WriteMode,
    pub max_rows_per_group: usize,
    pub max_values_per_group: usize,
    pub column_defaults: Option<ColumnOptions>,
    pub column_options: HashMap<String, ColumnOptions>,
    pub stats: bool,
    pub casting: Casting,
    pub target_fragment_bytes: usize,
    pub write_parallelism: usize,
    pub storage_options: StorageOptions,
}

Options for write() and append().

Fields

mode: WriteMode

How write() treats an existing table. append() ignores it.

max_rows_per_group: usize

Most rows that a writer encodes as one group.

max_values_per_group: usize

Most nd values that a writer encodes as one group. A group ends after the row that reaches it.

column_defaults: Option<ColumnOptions>

Encoding defaults for the columns of a new table. The table stores them and gives them to each column that a later write adds. For an existing table, they must be None or equal to the stored defaults.

column_options: HashMap<String, ColumnOptions>

Encoding options per column name, over the defaults. They apply when this write adds the column. Lance keeps them for later appends.

stats: bool

Store the min and max of each variable per row, see FORMAT.md section 7. Only a new table or an overwrite reads it. An append writes stats when the table has them.

casting: Casting

How a write treats a variable or attribute type that differs from the table, see Casting.

target_fragment_bytes: usize

crate::NdWriter buffers rows until they have about this many bytes on disk, then writes them as one Lance fragment. The writer learns the ratio of disk to memory bytes from the fragments it wrote. Before the first fragment, it counts bytes in memory. The buffer holds at most 8 times this size in memory. A row is never split. write() ignores it.

write_parallelism: usize

The most fragments that crate::NdWriter writes at the same time.

storage_options: StorageOptions

Lance storage options, for example the credentials of an object store, see crate::StorageOptions. append() uses the options of its table when this is empty.

Trait Implementations

impl Clone for WriteOptions

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for WriteOptions

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for WriteOptions

fn default() -> Self

Returns the “default value” for a type.