{"record":{"id":"508e09dcbee54893","repo":"pola-rs/polars","slug":"polars-maximum-length-reached-consider-compiling","errorCode":null,"errorMessage":"Polars' maximum length reached. Consider compiling with 'bigidx' feature.","messagePattern":"Polars' maximum length reached\\. Consider compiling with 'bigidx' feature\\.","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"critical","filePath":"crates/polars-core/src/series/implementations/null.rs","lineNumber":30,"sourceCode":"impl Series {\n    pub fn new_null(name: PlSmallStr, len: usize) -> Series {\n        NullChunked::new(name, len).into_series()\n    }\n}\n\n#[derive(Clone)]\npub struct NullChunked {\n    pub(crate) name: PlSmallStr,\n    length: usize,\n    // we still need chunks as many series consumers expect\n    // chunks to be there\n    chunks: Vec<ArrayRef>,\n}\n\nimpl NullChunked {\n    pub(crate) fn new(name: PlSmallStr, len: usize) -> Self {\n        if len >= (IdxSize::MAX as usize) && chunkops::CHECK_LENGTH.get() {\n            panic!(\"{}\", LENGTH_LIMIT_MSG);\n        }\n\n        Self {\n            name,\n            length: len,\n            chunks: vec![Box::new(arrow::array::NullArray::new(\n                ArrowDataType::Null,\n                len,\n            ))],\n        }\n    }\n\n    pub fn len(&self) -> usize {\n        self.length\n    }\n\n    pub fn is_empty(&self) -> bool {\n        self.length == 0","sourceCodeStart":12,"sourceCodeEnd":48,"githubUrl":"https://github.com/pola-rs/polars/blob/68506541d2de983056c9eb244e1ea05fab377dfc/crates/polars-core/src/series/implementations/null.rs#L12-L48","documentation":"By default polars indexes rows with IdxSize = u32 (max ~4.29 billion). NullChunked::new (used for any Null-dtyped series creation) checks the requested length and panics with LENGTH_LIMIT_MSG when it reaches IdxSize::MAX, advising to compile with the bigidx feature which switches IdxSize to u64.","triggerScenarios":"Materializing a Null/empty-typed Series with length >= 2^32: pl.Series of dtype Null with a huge size hint, range(5_000_000_000) eager materialization, giant broadcasts, or cross joins that create more than 4.29e9 rows on a default (non-bigidx) build.","commonSituations":"Large-scale ETL (multi-billion row ranges, cross joins, reindexes) on the standard wheel/build; code ported from systems with 64-bit indexes; tests with synthetic huge lengths.","solutions":["Enable the bigidx feature (Rust: features = [\"bigidx\"]) so indexes become u64","Reduce the materialized length: process in chunks, or keep the operation lazy/streaming so rows are never fully materialized","Guard user-supplied sizes against the 2^32 limit and fail with a clear error before calling into polars"],"exampleFix":"# before\ns = pl.repeat(None, 5_000_000_000, dtype=pl.Null, eager=True)  # panics\n\n# after\n# rust: polars = { features = [\"bigidx\"] }\n# or keep it lazy / chunk the work\nlf = pl.select(pl.repeat(None, 5_000_000_000, dtype=pl.Null)).lazy()","handlingStrategy":"validation","validationCode":"const IDX_MAX: usize = u32::MAX as usize; // default IdxSize\nfn length_allowed(len: usize) -> bool {\n    len < IDX_MAX\n}","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Enable the bigidx feature when data can exceed ~4.29 billion rows","Guard user-supplied sizes/lengths against 2^32 before materializing Series","Keep huge operations lazy/streaming so rows are never fully materialized in one Series"],"tags":["polars","bigidx","index-overflow","length-limit","panic","memory-scale"],"backgroundTag":"index-overflow-bigidx","analyzedSha":"68506541d2de983056c9eb244e1ea05fab377dfc","analyzedAt":"2026-08-19T12:15:06.350Z","contentChangedAt":"2026-08-19T12:15:06.350Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}