CostConfig class

Constructors

CostConfig({double seqIoCost = 1.0, double randomIoCost = 1.25, double cpuTupleCost = 0.01, double cpuOperatorCost = 0.0025, double indexFetchCost = 0.5, double rowsPerPage = 60.0})

const

Properties

cpuOperatorCost → double

CPU cost per operator evaluation (comparisons, expressions).

final

cpuTupleCost → double

CPU cost per tuple processed.

final

hashCode → int

The hash code for this object.

no setter, inherited

indexFetchCost → double

Additional cost for each index fetch (tree traversal amortized).

final

randomIoCost → double

Random I/O cost per page. HDD: 4.0 | NVMe SSD: 1.25 | In-memory: 0.2

final

rowsPerPage → double

Estimated rows per page (used when pageCount is unknown). For 4096-byte pages with typical 64-byte binary tuples: ~60 rows/page. The original value of 16 was based on JSON row sizes (~200 bytes).

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

seqIoCost → double

Sequential I/O cost per page (baseline = 1.0).

final

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Constants

hdd → const CostConfig

HDD-tuned constants (for rotating disk deployments).

memory → const CostConfig

All-in-memory (benchmarking / WAL-bypass mode).

nvme → const CostConfig

NVMe SSD (default — NebulaDB target platform).