mirror of https://github.com/lancedb/lancedb.git synced 2026-10-12 14:52:26 +00:00

Files

T

XY Zhan 2bf70758a7 fix: read back the maintained-index selection a table was given (#4447 )

`maintained_indexes` on a MemWAL table has three values: a named list,
`[]` for none, and `null` for every index the table has, including ones
created later. This PR makes every client read all three back as they
were set.

- **Rust remote client** (also used by the Python and Node SDKs) reads
`null` as `None`.
- **Java client** reads `null` as `null`, not as an empty list.
- **Docs** for the setter, the field and the getter describe the three
values the same way in Rust, Python, Node and Java. The generated JS
docs are regenerated to match.

## Testing

- `rust/lancedb`: 73 LSM tests pass, including one case per value. With
the decoder typed as a list, the `null` case fails.
- Java: two cases for `null` and `[]` on the read path, run by the Java
CI job.
- `cargo fmt`, `cargo clippy -D warnings` and `ruff format` are clean.

2026-10-06 19:07:10 -04:00

2.3 KiB

Raw Blame History

LanceDB Java Enterprise Client

Configuration and Initialization

LanceDB Cloud

For LanceDB Cloud, use the simplified builder API:

import com.lancedb.LanceDbNamespaceClientBuilder;
import org.lance.namespace.LanceNamespace;

// If your DB url is db://example-db, then your database here is example-db
LanceNamespace namespaceClient = LanceDbNamespaceClientBuilder.newBuilder()
    .apiKey("your_lancedb_cloud_api_key")
    .database("your_database_name")
    .build();

LanceDB Enterprise

For Enterprise deployments, use your custom endpoint:

LanceNamespace namespaceClient = LanceDbNamespaceClientBuilder.newBuilder()
    .apiKey("your_lancedb_enterprise_api_key")
    .database("your_database_name")
    .endpoint("<your_enterprise_endpoint>")
    .build();

MemWAL LSM write path

Most table operations reach LanceDB through the LanceNamespace above, which is generated from the Lance Namespace specification. The MemWAL LSM routes are not part of that specification, so they are issued through a separate client:

import com.lancedb.LanceDbRestClient;
import com.lancedb.LanceDbTableLsm;
import com.lancedb.LsmWriteSpec;

LanceDbRestClient client = LanceDbNamespaceClientBuilder.newBuilder()
    .apiKey("your_lancedb_cloud_api_key")
    .database("your_database_name")
    .buildRestClient();

LanceDbTableLsm lsm = new LanceDbTableLsm(client, "my_table");

// Route future merge_insert upserts through the MemWAL, hash-bucketed by `id`.
lsm.setLsmWriteSpec(LsmWriteSpec.bucket("id", 16));

// ... merge_insert traffic ...

// Converge the fresh tier into the base table.
lsm.checkpointLsm();

// Inspect live per-bucket state.
lsm.getLsmStats().ifPresent(stats -> stats.buckets().forEach(bucket ->
    System.out.println(bucket.shardId() + ": " + bucket.generations().size() + " L0 generations")));

client.close();

maintainedIndexes is tri-state, and the null default is the opposite of what a Java reader usually expects:

Value	Meaning
unset (null)	Maintain every index the table has, including ones created later
`Collections.emptyList()`	Maintain none
`Arrays.asList("id_idx")`	Maintain exactly those

Development

Build:

./mvnw install -pl lancedb-core -am

Run tests:

./mvnw test -pl lancedb-core

2.3 KiB Raw Blame History