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Jack Ye
21f11b4463
A 1M-row column refresh over 200 fragments produced no visible result,
and the client could only ever say `"running"`. Everything needed to
diagnose it already existed server-side — the job registry records a
`claim`/`claim_complete` pair per fragment carrying `rows_processed` —
but none of it was reachable.
## Before
Four ways to ask about a job, none of which told you much.
```python
job = table.refresh_column_async("embedding")
job.status() # "running". That was the entire debug surface.
db.get_job(job_id) # state, and a spec. No result, no progress.
db.job_history(job_id) # raw record batches, no limit, no filter
db.job(job_id) # a handle that knew nothing
```
## After
Open a job the way you open a table; the handle answers everything.
```python
job = db.open_job(job_id) # raises JobNotFoundError if there is no such job
```
```python
>>> print(job)
Job(
id='job-1',
state='failed',
job_type='refresh_column',
creation_ms=1757000000000,
spec={
"column": "embedding",
"num_workers": 4
},
failure=JobFailureInfo(phase='execute', message='worker died', retryable=True),
)
```
Individual fields are there too — `job.state`, `job.job_type`,
`job.creation_ms`, `job.spec`, `job.result`, `job.failure` — and
`job.result` carries `rows_assigned` / `rows_failed` as soon as the job
succeeds, with no `wait()` required.
Per-fragment progress *while it is still running*:
```python
done = job.events(filter="state = 'claim_complete'", limit=10_000)
done.column("rows_processed").to_pylist() # [5000, 5000, ...]
```
The handle an async action returns is the same object, one `refresh()`
away:
```python
job = table.refresh_column_async("embedding")
job.refresh()
job.state, job.result
```
TypeScript is the same experience, down to `console.log`:
```ts
const job = await db.openJob(jobId); // rejects if there is no such job
console.log(job); // same multi-line layout
job.state; job.jobType; job.spec; job.result; job.failure;
const done = await job.events({ filter: "state = 'claim_complete'", limit: 10_000 });
```
## Why each piece matters
- **A result without waiting.** `rows_assigned` / `rows_failed` used to
live only on the terminal result, so a job that never terminated
reported nothing at all.
- **`limit`.** The server caps event rows at 1000 and truncates without
saying so, which silently hid most of a 200-fragment job's history.
- **`filter`.** `claim_complete` rows carry per-claim `rows_processed` —
the only progress signal that exists mid-flight.
- **Events outlive the worker.** They live in the job registry, not in
pod logs that vanish with the pod.
- **One place to ask.** `open_job` replaces `describe_job`,
`query_job_events` and `job`, so a question about a job has one answer
instead of one per calling location.
- **A missing job is an error, not a `None`.** The common case is a job
id copied out of a log, where absence is the surprise worth raising —
and it matches `open_table`.
- **Printing is the debug surface.** Every field on its own line, JSON
payloads keeping their structure. An unrefreshed handle stays on one
line, because there is nothing to lay out.
- **In-process jobs say so.** A local refresh reports `state` and leaves
the rest null rather than inventing fields it has no record for.
`list_jobs` and `cancel_job` stay as they were: one lists, the other is
a one-shot action that should not need a describe first.
## Breaking
All shipped in 0.38.0. No deprecated aliases.
| Was | Now |
| --- | --- |
| `Connection.get_job` → `describe_job` | `Connection.open_job` returns
a populated `Job`, or raises |
| `Connection.job_history` → `query_job_events` | `job.events(...)` |
| `Connection.job` | `Connection.open_job` |
| Python events → `List[pa.RecordBatch]` | `pa.Table` |
| `JobDescription.spec_json` / `.result_json` | internal; use `job.spec`
/ `job.result` |
Node's `Job` is now a TypeScript class wrapping the native handle, so it
returns an Arrow table and parsed values like Python does. New
`Error::JobNotFound` / `JobNotFoundError`; the three job exceptions are
now in the Python API reference.
@lancedb/lancedb • Docs
LanceDB JavaScript SDK
A JavaScript library for LanceDB.
Installation
npm install @lancedb/lancedb
This will download the appropriate native library for your platform. We currently support:
- Linux (x86_64 and aarch64 on glibc and musl)
- MacOS (Intel and ARM/M1/M2)
- Windows (x86_64 and aarch64)
Usage
Basic Example
import * as lancedb from "@lancedb/lancedb";
const db = await lancedb.connect("data/sample-lancedb");
const table = await db.createTable("my_table", [
{ id: 1, vector: [0.1, 1.0], item: "foo", price: 10.0 },
{ id: 2, vector: [3.9, 0.5], item: "bar", price: 20.0 },
]);
const results = await table.vectorSearch([0.1, 0.3]).limit(20).toArray();
console.log(results);
The quickstart contains more complete examples.
Development
See CONTRIBUTING.md for information on how to contribute to LanceDB.