Type Alias Levelled

pub type Levelled = Leveled;

Alias for Leveled

Aliased Type

struct Levelled {
    pub l0_threshold: u8,
    pub target_size: u32,
    pub level_ratio: u8,
}

Fields

l0_threshold: u8

When the number of segments in L0 reaches this threshold, they are merged into L1

Default = 4

Same as level0_file_num_compaction_trigger in RocksDB

target_size: u32

Target segment size (compressed)

Default = 64 MiB

Same as target_file_size_base in RocksDB

level_ratio: u8

Size ratio between levels of the LSM tree (a.k.a fanout, growth rate)

This is the exponential growth of the from one. level to the next

A level target size is: max_memtable_size * level_ratio.pow(#level + 1)