ddn.data.arrow

Pure-D Apache Arrow C Data Interface and IPC file interchange for columnar data.

This package owns the standard interchange boundary of the DDN Analytics family: the Arrow C Data Interface (ArrowArray and ArrowSchema ABI structs with release callbacks), the admitted type mappings to and from the canonical columnar types, and the Arrow IPC file format - the minimal self-owned FlatBuffers subset, record-batch readers and writers, dictionary messages and LZ4 frame body compression through the DDN pure-D compressor provider.

It is a pure-D implementation of the standard formats, not a binding to the Arrow C++ library: no C++ or Python dependency, Arrow Flight, C Stream Interface or IPC stream format is part of it. Its API consumes and produces schemas, columns and batches over ddn-columnar; dataframes, lazy frames and query plans belong to the integration package above it.

The admitted subset stays the delivered one: buffer sharing on export where the layout matches, copy-on-import, decimal widening and narrowing within int64 coefficients, and explicit rejection of unsupported shapes and codecs.

The delivered surface includes the complete admitted C Data and IPC subset with independent C and pyarrow conformance probes owned by this package. Compatibility re-exports preserve historical imports for IO consumers without introducing frame or query dependencies.