Explain the internal working of LanceDB's zero-copy data access via Arrow?

Zero-copy access means that when data moves between LanceDB and another Arrow-compatible tool, the underlying bytes in memory don't need to be copied or re-serialized into a different format — both sides simply agree on and read the same memory layout directly.

Because Arrow defines a precise, language-independent specification for how columnar data is laid out in memory — contiguous buffers per column, with a well-defined format per data type — any tool that understands the Arrow spec can read a buffer produced by a completely different tool without needing to parse or transform it first.

In practice, this means a query result from LanceDB can be handed to Pandas as a DataFrame, or to DuckDB for further SQL analysis, or to Polars, all without a serialization step in between; the performance benefit compounds when working with very large result sets, since the cost of a full copy and reformat scales with data size, while zero-copy access avoids that cost regardless of how much data is being passed along.