Implementation:Lance format Lance Java BTreeIndexParams

Knowledge Sources	Lance
Domains	Java_SDK, Indexing
Last Updated	2026-02-08 19:33 GMT

Overview

Description

BTreeIndexParams is a final Java class in the org.lance.index.scalar package that provides a builder-style configuration for B-Tree scalar index parameters. It is a convenience wrapper that constructs a ScalarIndexParams instance with the index type set to "btree". The builder supports two optional parameters: zoneSize (number of rows per zone) and rangeId (ordinal ID for distributed BTree index builds). Parameters are serialized to JSON using JsonUtils and passed to ScalarIndexParams.create().

Usage

Use BTreeIndexParams.builder() to configure B-Tree index options. The build() method returns a ScalarIndexParams object (not a BTreeIndexParams instance), which can then be set on an IndexParams builder.

Code Reference

Source Location

java/src/main/java/org/lance/index/scalar/BTreeIndexParams.java

Signature

public final class BTreeIndexParams {
    public static Builder builder();

    public static final class Builder {
        public Builder zoneSize(long zoneSize);
        public Builder rangeId(int rangeId);
        public ScalarIndexParams build();
    }
}

Import

import org.lance.index.scalar.BTreeIndexParams;

I/O Contract

Builder Inputs

Parameter	Type	Required	Default	Validation	Description
zoneSize	long	No	Not set	Must be positive	Number of rows per zone in the B-Tree
rangeId	int	No	Not set	Must be non-negative	Ordinal ID of a data partition for building a large, distributed BTree index

Build Output

Return Type	Description
ScalarIndexParams	A scalar index params object with type "btree" and optional JSON configuration

JSON Parameters (serialized internally)

Key	Type	Description
zone_size	long	Number of rows per zone
range_id	int	Range identifier for distributed builds

Usage Examples

import org.lance.index.scalar.BTreeIndexParams;
import org.lance.index.scalar.ScalarIndexParams;
import org.lance.index.IndexParams;

// Create a default BTree index (no custom zone size or range)
ScalarIndexParams defaultBTree = BTreeIndexParams.builder().build();

// Create a BTree index with a custom zone size
ScalarIndexParams customBTree = BTreeIndexParams.builder()
    .zoneSize(4096)
    .build();

// Create a distributed BTree with range partitioning
ScalarIndexParams distributedBTree = BTreeIndexParams.builder()
    .zoneSize(2048)
    .rangeId(3)
    .build();

// Wrap in IndexParams for use with IndexOptions
IndexParams params = IndexParams.builder()
    .setScalarIndexParams(customBTree)
    .build();

Related Pages

• ScalarIndexParams - The output type produced by BTreeIndexParams.Builder.build()
• IndexParams - Top-level container that holds scalar index params
• ZoneMapIndexParams - Another scalar index builder for zone map indices
• IndexType - Contains the BTREE enum constant