XY Zhan fbfb53e30f refactor(lsm): remove the index-catchup activation surface (#3980)
Follows lance-format/lance#8680, which removes
`FLAG_MEM_WAL_INDEX_CATCHUP`.
With one set of semantics there is no mode to switch into.

## Removed

`require_mem_wal_index_catchup` — the activation entry point — from the
trait,
from `Table`, and from the LSM merge module.

## The read path

`exclusion_watermarks` loses its `catchup_required` argument and keeps
the
conservative branch: an index with no entry is not known to hold these
rows, so
every generation stays readable from its SSTable. Nothing is excluded
until an
index records that it covers those generations, so a table that has
never
recorded catch-up reads every row from its SSTables rather than assuming
the
base covers them.

## One guard needed a replacement, not deletion

`refresh_column` and computed-column declaration refuse a table whose
rows sit
in un-compacted tiers, since refresh enumerates base fragments and would
silently omit them. They keyed on the feature bit because
`unset_lsm_write_spec` **drops the MemWAL index** — after an unset the
write
spec no longer describes such a table, and the bit was the only marker
that
outlived it. Two tests covered this, so deleting the term would have
dropped a
tested property.

Both guards now check for MemWAL shard directories on storage, which
outlive
the index. That is strictly wider than the bit ever was: the bit only
marked
tables where activation had run.

## Two tests conflated two different things

An index that is *caught up* and one that is *untracked* both fell back
to the
compaction watermark, because absence carried no information without the
bit.
Absence now means "not caught up", so untracked retains everything.
`an_untracked_index_does_not_widen_a_lagging_sibling` becomes
`an_untracked_index_retains_everything`, with the genuinely-caught-up
case
asserted separately.

## Testing

933 `lancedb` lib tests. `cargo fmt` clean. (The pre-existing
`Error::Http`
build failure in `job.rs` without the `remote` feature is unrelated and
untouched.)
2026-08-21 19:35:42 +08:00
2023-03-17 18:15:19 -07:00
2025-03-10 09:01:23 -07:00

LanceDB Cloud Public Beta

LanceDB Website Blog Discord Twitter LinkedIn

LanceDB

The Multimodal AI Lakehouse

How to Install Detailed DocumentationTutorials and RecipesContributors

The ultimate multimodal data platform for AI/ML applications.

LanceDB is designed for fast, scalable, and production-ready vector search. It is built on top of the Lance columnar format. You can store, index, and search over petabytes of multimodal data and vectors with ease. LanceDB is a central location where developers can build, train and analyze their AI workloads.


Demo: Multimodal Search by Keyword, Vector or with SQL

LanceDB Multimodal Search

Star LanceDB to get updates!

Click here to see how fast we're growing!

Key Features:

  • Fast Vector Search: Search billions of vectors in milliseconds with state-of-the-art indexing.
  • Comprehensive Search: Support for vector similarity search, full-text search and SQL.
  • Multimodal Support: Store, query and filter vectors, metadata and multimodal data (text, images, videos, point clouds, and more).
  • Advanced Features: Zero-copy, automatic versioning, manage versions of your data without needing extra infrastructure. GPU support in building vector index.

Products:

  • Open Source & Local: 100% open source, runs locally or in your cloud. No vendor lock-in.
  • Cloud and Enterprise: Production-scale vector search with no servers to manage. Complete data sovereignty and security.

Ecosystem:

  • Columnar Storage: Built on the Lance columnar format for efficient storage and analytics.
  • Seamless Integration: Python, Node.js, Rust, and REST APIs for easy integration. Native Python and Javascript/Typescript support.
  • Rich Ecosystem: Integrations with LangChain 🦜🔗, LlamaIndex 🦙, Apache-Arrow, Pandas, Polars, DuckDB and more on the way.

How to Install:

Follow the Quickstart doc to set up LanceDB locally.

API & SDK: We also support Python, Typescript and Rust SDKs

Interface Documentation
Python SDK https://lancedb.github.io/lancedb/python/python/
Typescript SDK https://lancedb.github.io/lancedb/js/globals/
Rust SDK https://docs.rs/lancedb/latest/lancedb/index.html
REST API https://docs.lancedb.com/api-reference/rest

Join Us and Contribute

We welcome contributions from everyone! Whether you're a developer, researcher, or just someone who wants to help out.

If you have any suggestions or feature requests, please feel free to open an issue on GitHub or discuss it on our Discord server.

Check out the GitHub Issues if you would like to work on the features that are planned for the future. If you have any suggestions or feature requests, please feel free to open an issue on GitHub.

Contributors

Stay in Touch With Us


Website Blog Discord Twitter LinkedIn

S
Description
Languages
Rust 37.6%
HTML 28.9%
Python 25.1%
TypeScript 7.2%
Java 0.9%
Other 0.2%