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XY Zhan
2bf70758a7
`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.
87 lines
2.3 KiB
Markdown
87 lines
2.3 KiB
Markdown
# LanceDB Java Enterprise Client
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## Configuration and Initialization
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### LanceDB Cloud
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For LanceDB Cloud, use the simplified builder API:
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```java
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import com.lancedb.LanceDbNamespaceClientBuilder;
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import org.lance.namespace.LanceNamespace;
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// If your DB url is db://example-db, then your database here is example-db
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LanceNamespace namespaceClient = LanceDbNamespaceClientBuilder.newBuilder()
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.apiKey("your_lancedb_cloud_api_key")
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.database("your_database_name")
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.build();
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```
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### LanceDB Enterprise
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For Enterprise deployments, use your custom endpoint:
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```java
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LanceNamespace namespaceClient = LanceDbNamespaceClientBuilder.newBuilder()
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.apiKey("your_lancedb_enterprise_api_key")
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.database("your_database_name")
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.endpoint("<your_enterprise_endpoint>")
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.build();
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```
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## MemWAL LSM write path
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Most table operations reach LanceDB through the `LanceNamespace` above, which is
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generated from the Lance Namespace specification. The MemWAL LSM routes are not part
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of that specification, so they are issued through a separate client:
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```java
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import com.lancedb.LanceDbRestClient;
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import com.lancedb.LanceDbTableLsm;
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import com.lancedb.LsmWriteSpec;
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LanceDbRestClient client = LanceDbNamespaceClientBuilder.newBuilder()
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.apiKey("your_lancedb_cloud_api_key")
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.database("your_database_name")
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.buildRestClient();
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LanceDbTableLsm lsm = new LanceDbTableLsm(client, "my_table");
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// Route future merge_insert upserts through the MemWAL, hash-bucketed by `id`.
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lsm.setLsmWriteSpec(LsmWriteSpec.bucket("id", 16));
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// ... merge_insert traffic ...
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// Converge the fresh tier into the base table.
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lsm.checkpointLsm();
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// Inspect live per-bucket state.
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lsm.getLsmStats().ifPresent(stats -> stats.buckets().forEach(bucket ->
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System.out.println(bucket.shardId() + ": " + bucket.generations().size() + " L0 generations")));
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client.close();
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```
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`maintainedIndexes` is tri-state, and the null default is the opposite of what a Java
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reader usually expects:
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| Value | Meaning |
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| --- | --- |
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| unset (null) | Maintain **every** index the table has, including ones created later |
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| `Collections.emptyList()` | Maintain **none** |
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| `Arrays.asList("id_idx")` | Maintain exactly those |
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## Development
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Build:
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```shell
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./mvnw install -pl lancedb-core -am
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```
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Run tests:
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```shell
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./mvnw test -pl lancedb-core
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```
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