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

Open All

798 open issues indexed

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
fix_schema renumbers a duplicated nested field without re-parenting its children, leaving the dataset unopenable Open

Difficulty 4/5 3-5 days Newbie friendliness 65/100

lance-format/lance#9424 · 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
perf: reading a shuffle partition plans one empty range per flush group it is absent from Open

performance

Difficulty 3/5 1-2 days Newbie friendliness 74/100

lance-format/lance#9412 · 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: a panic in the shuffle transform aborts the build instead of returning an error Open

bug

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

lance-format/lance#9404 · Opened Sep 18, 2026
Memory pool failures for query::primitives::test_query_integer::case_7_uint32 Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 48/100

lance-format/lance#9402 · 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
perf: the IVF shuffle sorts a key tuple per row when partition ids are already bucketable Open

performance

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

lance-format/lance#9381 · Opened Sep 18, 2026
perf: opening an IVF index reads its two global buffers one after the other Open

performance

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

lance-format/lance#9377 · Opened Sep 18, 2026
bug: the current IVF build path does not enforce the precomputed-input contracts Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 52/100

lance-format/lance#9375 · Opened Sep 18, 2026
perf: KeepFiniteVectors walks every row even when the whole batch is finite Open

performance

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

lance-format/lance#9370 · 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: pre-computed IVF centroids are only length-checked, so wrong-shaped ones break the build later Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 68/100

lance-format/lance#9365 · Opened Sep 18, 2026
Feature request: error handling for `push_uri` API for error handling Open

feature

Difficulty 5/5 Over a week Newbie friendliness 35/100

lance-format/lance#9362 · Opened Sep 17, 2026
bug: PartitionTransformer::new unwraps a fallible index build Open

bug

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

lance-format/lance#9348 · Opened Sep 17, 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: a malformed precomputed partitions file panics the index build Open

bug

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

lance-format/lance#9341 · Opened Sep 17, 2026
bug: binding docstrings say stable row ids do not survive an update Open

bug

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

lance-format/lance#9327 · Opened Sep 17, 2026
perf: delete builds the dataset-wide row id index only to translate ids it does not need Open

performance

Difficulty 3/5 1-2 days Newbie friendliness 74/100

lance-format/lance#9320 · Opened Sep 16, 2026
bug: comparing a boolean column with a boolean expression fails to plan when the expression contains a literal Open

bug

Difficulty 3/5 1-2 days Newbie friendliness 68/100

lance-format/lance#9319 · 1 comment · Opened Sep 16, 2026
perf: a double-typed literal against a Float32 column casts the column and skips its index Open

performance

Difficulty 3/5 1-2 days Newbie friendliness 74/100

lance-format/lance#9318 · Opened Sep 16, 2026
feature: accept a float literal against an integer column in filters Open

feature

Difficulty 4/5 3-5 days Newbie friendliness 58/100

lance-format/lance#9317 · Opened Sep 16, 2026
bug: -0.0 and 0.0 still compare unequal between columns and in array_has Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 55/100

lance-format/lance#9316 · 1 comment · Opened Sep 16, 2026
bug: a NaN with its sign bit set sorts below every number in filters Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 52/100

lance-format/lance#9315 · 1 comment · Opened Sep 16, 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: the scratch dir leak tests can pass without checking anything Open

bug

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

lance-format/lance#9283 · Opened Sep 16, 2026
perf: scope scalar prefilters to selected vector index segments Open

performance

Difficulty 5/5 Over a week Newbie friendliness 35/100

lance-format/lance#9282 · 1 reaction · Opened Sep 16, 2026
Merging index segments after deferred-remap compaction silently drops live entries Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 58/100

lance-format/lance#9270 · 1 comment · Opened Sep 16, 2026
Cluster base data in accordance with index structure Open

feature

Difficulty 5/5 Over a week Newbie friendliness 30/100

lance-format/lance#9266 · 1 comment · 4 reactions · Opened Sep 16, 2026
feature: let the v3 shufflers own their shuffle scratch directory Open

feature performance

Difficulty 4/5 3-5 days Newbie friendliness 65/100

lance-format/lance#9264 · 1 reaction · Opened Sep 16, 2026
feat: make load_segment_params generic over scalar index types, not inverted-only Open

feature

Difficulty 4/5 3-5 days Newbie friendliness 58/100

lance-format/lance#9258 · Opened Sep 15, 2026
bug: JSON index on a nested path is matched by typed accessors that cannot evaluate it, so indexed and unindexed results disagree Open

bug performance

Difficulty 3/5 1-2 days Newbie friendliness 68/100

lance-format/lance#9257 · Opened Sep 15, 2026
JsonIndexDetails cannot represent target_data_type, so details are insufficient to rebuild a JSON index Open

lance-format/lance#9256 · 2 comments · 1 assignee · Opened Sep 15, 2026
§5.3 Row ID sequences spill to data files as a hidden column Open

lance-format/lance#9250 · 1 assignee · Opened Sep 15, 2026
bug: compaction fails determinstically on a very small-fragment dataset Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 42/100

lance-format/lance#9224 · Opened Sep 14, 2026

lance-format/lance

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