Struct KeyspaceCreateOptions 

pub struct KeyspaceCreateOptions {
    pub data_block_hash_ratio_policy: HashRatioPolicy,
    /* private fields */
}

Options to configure a keyspace

Fields

data_block_hash_ratio_policy: HashRatioPolicy

Data block hash ratio

Implementations

impl CreateOptions

pub fn with_kv_separation(self, opts: Option<KvSeparationOptions>) -> Self

Toggles key-value separation.

pub fn data_block_restart_interval_policy( self, policy: RestartIntervalPolicy, ) -> Self

Sets the restart interval inside data blocks.

A higher restart interval saves space while increasing lookup times inside data blocks.

Default = 16

pub fn filter_block_pinning_policy(self, policy: PinningPolicy) -> Self

Sets the pinning policy for filter blocks.

By default, L0 filter blocks are pinned.

pub fn index_block_pinning_policy(self, policy: PinningPolicy) -> Self

Sets the pinning policy for index blocks.

By default, L0 and L1 index blocks are pinned.

pub fn filter_block_partitioning_policy( self, policy: PartitioningPolicy, ) -> Self

Sets the partitioning policy for filter blocks.

pub fn index_block_partitioning_policy(self, policy: PartitioningPolicy) -> Self

Sets the partitioning policy for index blocks.

pub fn filter_policy(self, policy: FilterPolicy) -> Self

Sets the filter policy for data blocks.

pub fn expect_point_read_hits(self, b: bool) -> Self

If true, the last level will not build filters, reducing the filter size of a database by ~90% typically.

Enable this only if you know that point reads generally are expected to find a key-value pair.

pub fn data_block_compression_policy(self, policy: CompressionPolicy) -> Self

Sets the compression policy for data blocks.

pub fn index_block_compression_policy(self, policy: CompressionPolicy) -> Self

Sets the compression policy for index blocks.

pub fn compaction_strategy( self, compaction_strategy: Arc<dyn CompactionStrategy + Send + Sync>, ) -> Self

Sets the compaction strategy.

Default = Leveled

pub fn manual_journal_persist(self, flag: bool) -> Self

If false, writes will flush data to the operating system.

Default = false

Set to true to handle persistence manually, e.g. manually using PersistMode::SyncData.

pub fn max_memtable_size(self, bytes: u64) -> Self

Sets the maximum memtable size.

Default = 64 MiB

Recommended size 8 - 64 MiB, depending on how much memory is available.

Conversely, if max_memtable_size is larger than 64 MiB, it may require increasing the database’s max_write_buffer_size.

pub fn data_block_size_policy(self, policy: BlockSizePolicy) -> Self

Sets the block size.

Once set for a keyspace, this property is not considered in the future.

Default = 4 KiB

For point read heavy workloads (get) a sensible default is somewhere between 4 - 8 KiB, depending on the average value size.

For more space efficiency, block size between 16 - 64 KiB are sensible.

Panics

Panics if the block size is smaller than 1 KiB or larger than 1 MiB.

Trait Implementations

impl Clone for CreateOptions

fn clone(&self) -> CreateOptions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Default for CreateOptions

fn default() -> Self

Returns the “default value” for a type.