> Stacked on #3780. Blocked only on #3922 (`lance` → `v11.0.0-beta.6`), so CI > stays red until that lands. ## Missing coverage must mean "not known to be covered" #3780 caps the SSTable exclusion watermark at an index's recorded catch-up when there is one, and silently ignores the case where there is none. On a table that requires catch-up, an absent entry means the index is *not* known to hold the compacted rows — and the LSM base arm reads base through the index (`fast_search`, no brute-force tail), so dropping that SSTable loses those rows for that query. ```rust Some(caught_up) => watermark = watermark.min(caught_up), None if catchup_required => watermark = 0, // retain everything None => {} ``` `catchup_required` reads the manifest feature bit directly, and requires both words: a half-set manifest is treated as legacy, which is the conservative side. Without the bit the field is not maintained at all, so absence carries no information and behaviour is unchanged. ## Activation, as a table-level entry point `Table::require_mem_wal_index_catchup()` performs the one-way switch, separate from `set_lsm_write_spec`: a table carrying the bit retains every generation until something records catch-up, so it has to follow the deployment of whatever repairs coverage, not the creation of the table. This is a convenience, not the only path — a writer holding the dataset calls the equivalent on `DatasetMemWalExt`, which is what the WAL pod does. Lance enforces the preconditions either way: the MemWAL index must exist, and the table must not already carry `compacted_sstables` from before this protocol, since those numbers cannot be validated. ## Still correct after the Lance rework lance-format/lance#8481 replaced the transmitted `IndexCatchupAdvance` with a position derived at commit time from the version a transaction read. That changed how a writer earns coverage; it did not change what a reader may conclude from its absence. The rule here, and the field it reads, are unchanged. ## Tests Existing `exclusion_watermarks` unit tests carry the new argument. Coverage against a real dataset follows once #3922 lands and this can build.
The Multimodal AI Lakehouse
How to Install ✦ Detailed Documentation ✦ Tutorials and Recipes ✦ Contributors
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
Star LanceDB to get updates!
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.
