Implementation:Lance format Lance Java IndexCriteria

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

Overview

Description

IndexCriteria is a final Java class in the org.lance.index package that defines criteria for describing or selecting indices on a Lance dataset. It mirrors the semantics of the Rust IndexCriteria struct used by Dataset::describe_indices and related APIs. The class uses an immutable design with a Builder pattern and allows filtering indices by column name, index name, full-text search support, and exact equality predicate support.

Usage

IndexCriteria is constructed via its inner Builder class and passed to dataset methods that list or describe indices. By setting criteria fields, callers can narrow down which indices are returned. All filter fields are optional; when omitted, all indices are considered.

Code Reference

Source Location

java/src/main/java/org/lance/index/IndexCriteria.java

Signature

public final class IndexCriteria {
    public Optional<String> getForColumn();
    public Optional<String> getHasName();
    public boolean mustSupportFts();
    public boolean mustSupportExactEquality();

    public static final class Builder {
        public Builder forColumn(String forColumn);
        public Builder hasName(String name);
        public Builder mustSupportFts(boolean mustSupportFts);
        public Builder mustSupportExactEquality(boolean mustSupportExactEquality);
        public IndexCriteria build();
    }
}

Import

import org.lance.index.IndexCriteria;

I/O Contract

Builder Inputs

Parameter	Type	Required	Default	Description
forColumn	String	No	null (no filter)	Restrict to indices built on this column only
hasName	String	No	null (no filter)	Restrict to indices with this specific name
mustSupportFts	boolean	No	false	If true, only indices supporting full-text search
mustSupportExactEquality	boolean	No	false	If true, only indices supporting exact equality predicates

Accessor Outputs

Method	Return Type	Description
getForColumn()	Optional<String>	Column name filter, if set
getHasName()	Optional<String>	Index name filter, if set
mustSupportFts()	boolean	Whether FTS support is required
mustSupportExactEquality()	boolean	Whether exact equality support is required

Usage Examples

import org.lance.index.IndexCriteria;

// Find all indices on the "embedding" column
IndexCriteria criteria = new IndexCriteria.Builder()
    .forColumn("embedding")
    .build();

// Find a specific index by name
IndexCriteria byName = new IndexCriteria.Builder()
    .hasName("my_btree_idx")
    .build();

// Find indices that support full-text search
IndexCriteria ftsCriteria = new IndexCriteria.Builder()
    .mustSupportFts(true)
    .build();

// Combine criteria: column + exact equality support
IndexCriteria combined = new IndexCriteria.Builder()
    .forColumn("category")
    .mustSupportExactEquality(true)
    .build();

Related Pages

• IndexDescription - Returned by describe-indices APIs that accept IndexCriteria
• Index - Per-segment index metadata
• IndexType - Enum classifying index types