lance-format/lance

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Open Lakehouse Format for Multimodal AI. Convert from Parquet in 2 lines of code for 100x faster random access, vector index, and data versioning. Compatible with Pandas, DuckDB, Polars, Pyarrow, and PyTorch with more integrations coming..

Stars: 7.1k
Forks: 852
Open beginner issues: 23
Indexed issues: 798
Avg merge: 3d 18h
Merged PRs (30d): 272

Dominant language: Rust
License: Apache-2.0
Last GitHub push: Sep 18, 2026
Latest indexed: Sep 18, 2026
Contributing guide: Contributing guide
Code of conduct: No code of conduct
Beginner labels: good first issue help wanted

Beginner friendly Everything

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27 beginner-friendly issues open

bug: build_ivf_model panics when num_partitions is unset Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 85/100

lance-format/lance#9428 · Opened Sep 18, 2026
bug: Flatten panics on a multivector batch without a row-id column Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 84/100

lance-format/lance#9425 · Opened Sep 18, 2026
bug: IVF_RQ with the hamming metric panics in the kmeans trainer Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 84/100

lance-format/lance#9422 · Opened Sep 18, 2026
bug: skip_transpose is ignored for IVF_HNSW_PQ Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

lance-format/lance#9418 · Opened Sep 18, 2026
bug: IVF_SQ and IVF_RQ on a UInt8 column train the whole IVF model before rejecting the dtype Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 84/100

lance-format/lance#9415 · Opened Sep 18, 2026
bug: the kmeans balance factor is NaN when nothing is assigned, and f32::min hides it Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 86/100

lance-format/lance#9406 · Opened Sep 18, 2026
bug: filter_nan=False is silently ignored on CPU index builds Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 78/100

lance-format/lance#9400 · Opened Sep 18, 2026
bug: IvfTransformer::new_flat stores the unconverted metric for cosine Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 84/100

lance-format/lance#9398 · Opened Sep 18, 2026
bug: license-header-check.yml never runs on java-only pull requests Open

bug

Difficulty 1/5 Under an hour Newbie friendliness 92/100

lance-format/lance#9397 · Opened Sep 18, 2026
bug: RQTransformer emits two different schemas depending on whether the batch was already encoded Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

lance-format/lance#9395 · Opened Sep 18, 2026
bug: NormalizeTransformer panics when its column is not a fixed-size list Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

lance-format/lance#9392 · Opened Sep 18, 2026
bug: the RQ transform panics instead of erroring when the partition column is missing Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

lance-format/lance#9390 · Opened Sep 18, 2026
bug: the Python binding drops shuffle_partition_batches Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

lance-format/lance#9387 · Opened Sep 18, 2026
bug: create_index accepts index_cache_size and silently ignores it Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 75/100

lance-format/lance#9383 · Opened Sep 18, 2026
bug: load_or_build_quantizer validates its params after sampling, and carries a dead match arm Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 84/100

lance-format/lance#9367 · Opened Sep 18, 2026
bug: weighted k-means pads the partition count with duplicate clusters, leaving them permanently empty Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 78/100

lance-format/lance#9345 · Opened Sep 17, 2026
bug: Project leaves overlays behind for the columns it drops Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

lance-format/lance#9313 · Opened Sep 16, 2026
perf: U64Segment::slice decodes and re-encodes a Range instead of slicing it in O(1) Open

performance

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

lance-format/lance#9308 · Opened Sep 16, 2026
bug: CapturedRowIds::row_addrs panics instead of returning an error Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 86/100

lance-format/lance#9306 · Opened Sep 16, 2026
bug: rechunk_sequences rejects a valid input when a sequence ends with an empty segment Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

lance-format/lance#9301 · Opened Sep 16, 2026
bug: select_row_ids panics on an out-of-bounds RangeFrom instead of returning InvalidInput Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

lance-format/lance#9297 · Opened Sep 16, 2026
bug: Windows CI flake - pytest-xdist workers race on the shared torchinductor cache Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 76/100

lance-format/lance#9055 · Opened Sep 8, 2026
bug: binary_quantization appends a spurious byte when the length is a multiple of 8 Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 84/100

lance-format/lance#9028 · Opened Sep 7, 2026
Upgrade DataFusion for the unparser stack-overflow fix Open

Difficulty 2/5 1-3 hours Newbie friendliness 72/100

lance-format/lance#8225 · Opened Aug 4, 2026
take_blobs: _rowaddr column duplicated on unsorted row ID path Open

enhancement

Difficulty 1/5 Under an hour Newbie friendliness 84/100

lance-format/lance#6425 · 2 comments · Opened Apr 7, 2026
Expose compute_pq_distance Open

enhancement

Difficulty 1/5 1-3 hours Newbie friendliness 62/100

lance-format/lance#5675 · 1 comment · Opened Jan 9, 2026
Update `encoding.md` for `MiniBlockChunk` minichunk size changes Open

documentation

Difficulty 1/5 1-3 hours Newbie friendliness 78/100

lance-format/lance#5240 · Opened Nov 14, 2025

lance-format/lance

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