Files
lancedb/python/python
Wyatt Alt 7ef2ecb873 feat: recompute computed column rows whose inputs changed
refresh_column fills nulls, so once a row has a value nothing revisits
it: an update to one of its inputs, or a definition change, leaves the
computed value stale for good.

This stamps the column's field metadata with the definition it was
computed under and a per-fragment signature of the input storage it was
read from (input data files and overlays; not the deletion file, since
a delete changes no surviving value). A refresh recomputes every live
row of a fragment whose stamp disagrees with the manifest, then records
what it computed from in a second commit after the fill. A compacted
fragment built from signed fragments inherits their freshness through
the Rewrite lineage; one built from an unsigned fragment recomputes. A
column declared before the stamps existed keeps the null-fill contract
on its first refresh, which enrolls it as it stood.

The stamp is a metadata-only commit on the computed columns, so a
materialized view's drift check treats it like the fill. The core lives
in `table::freshness` so a remote refresh can share the contract.
2026-09-10 22:34:58 +00:00
..