Problemsby GlyphPolars
Open source project60 problems196 posts+1 this week
Problem posts per week
Polars problems
Claude Code users keep filing bugs
Top post: "Bug Report: Privacy violation in User-Agent header", one of 42 posts from 39 people on GitHub issues, Reddit.
pandas users keep filing bugs
Top post: ".to_latex() throws an exception in some cases", one of 26 posts from 19 people on GitHub issues, Stack Overflow, Reddit.
Trouble with Polars column
Top post: "Compare lists in one column to the first n elements of another column in Python Polars lazyframes, where n is", one of 20 posts from 16 people on GitHub issues, Stack Overflow.
Small files, skew and partitioning hurt performance
14 posts from 14 people on GitHub issues, Hacker News.
Jobs and services run out of memory
14 posts from 14 people on GitHub issues, Stack Overflow, Reddit.
Claude Code tables suffer from small files and skew
9 posts from 9 people on GitHub issues, Reddit.
Trouble with pandas index
Top post: "DOC: document `pd.Index.to_flat_index`", one of 4 posts from 4 people on GitHub issues.
Trouble with Claude zero
Top post: "Azure AI Claude Mythos 5.1 has no cost-map entry and records zero spend", one of 2 posts from 2 people on GitHub issues. Unverified.
Polars upgrades break working setups
23 posts from 16 people on GitHub issues.
Polars users keep filing bugs
Top post: "Consider upgrading the brotli crate (CVE-2026-111497)", one of 22 posts from 15 people on GitHub issues.
Databases hit connection, locking and scaling limits
16 posts from 16 people on GitHub issues, Hacker News, Reddit.
Trouble with Apache Iceberg table
Top post: "Parquet files written with the default CRS are not compatible with Iceberg Java EPSG:4326 table", one of 12 posts from 8 people on GitHub issues.
Microsoft Fabric users keep asking for help
Top post: "SQL: support time-zone-aware timestamps (CAST AS TIMESTAMPTZ / TIMESTAMP WITH TIME ZONE, AT TIME ZONE)", one of 10 posts from 9 people on Reddit, GitHub issues.
Trouble with Polars unique
Top post: "Streaming engine: multi-column `.unique()` in `group_by().agg()` much slower than in-memory", one of 7 posts from 4 people on GitHub issues.
Trouble with Polars parquet
Top post: "`is_in` with more than 100 values does not skip Parquet row groups between the values", one of 7 posts from 7 people on GitHub issues.
Trouble with Polars join
Top post: "Coalescing full join on Int32-vs-Int64 keys with `unique` incorrect", one of 6 posts from 6 people on GitHub issues.
Trouble with Polars instead
Top post: "Series.to_list() panics on out-of-range datetimes instead of raising an error", one of 6 posts from 6 people on GitHub issues.
Vendor support is slow or unhelpful
6 posts from 6 people on Reddit, GitHub issues, Hacker News.
Trouble with pandas read
Top post: "CI: sanitizers environment has no pyarrow, so the read_csv pyarrow string path is never sanitized", one of 5 posts from 5 people on GitHub issues.
Trouble with Apache Spark rows
Top post: "scan_delta returns deleted rows from partitions whose path is percent-encoded", one of 4 posts from 4 people on GitHub issues, Stack Overflow.
Trouble with Polars group
Top post: "Datetime out-of-range in `group_by_dynamic` streaming engine", one of 4 posts from 3 people on GitHub issues.
Apache Spark upgrades break working setups
4 posts from 4 people on GitHub issues.
Apache Iceberg runs out of memory
4 posts from 3 people on GitHub issues.
Redis users keep filing bugs
Top post: "7.0.0rc2 Flight SQL/ADBC validation: source-install dependency failures and metadata gaps", one of 3 posts from 1 person on GitHub issues.
Trouble with Polars returns
Top post: "GPU `max_horizontal` returns NaN for a finite value followed by NaN", one of 3 posts from 2 people on GitHub issues.
Trouble with Apache Iceberg delete
Top post: "Iceberg DROP PARTITION aborts or republishes parent delete counters after an overwrite snapshot", one of 3 posts from 3 people on GitHub issues.
Trouble with Polars value
Top post: "polars.read_excel() value error on very large date", one of 3 posts from 3 people on GitHub issues.
Trouble with Polars true
Top post: "wrap_numerical=True saturates floats at the dtype maximum", one of 3 posts from 3 people on GitHub issues.
Trouble with Polars read
Top post: "`read_database` raises `ImportError` with SQLAlchemy 2.1 when `greenlet` is not installed", one of 3 posts from 3 people on GitHub issues.
About
Problems here are about Polars or name it. It is tracked from the product list on the Method page. Website: pola.rs.