Versioning

The Lance file format has a single version number for both the overall file format and the encoding strategy. The major number is changed when the file format itself is modified while the minor number is changed when only the encoding strategy is modified. Newer versions will typically have better performance and compression but may not be readable by older versions of Lance.

In addition, the next alias points to an unstable format version and should not be used for production use cases. Breaking changes could be made to unstable encodings and that would mean that files written with these encodings are no longer readable by any newer versions of Lance. The next version should only be used for experimentation and benchmarking upcoming features.

The stable and next aliases are resolved by the specific Lance release you are using. During a format rollout (for example, 2.2), prefer explicit version pinning for deterministic behavior across environments.

The following values are supported:

Version	Minimal Lance Version	Maximum Lance Version	Description
0.1	Any	0.34 (write)	This is the initial Lance format. It is no longer writable.
2.0	0.16.0	Any	Rework of the Lance file format that removed row groups and introduced null support for lists, fixed size lists, and primitives
2.1	0.38.1	Any	Enhances integer and string compression, adds support for nulls in struct fields, and improves random access performance with nested fields.
2.2 (unstable)	None	Any	Adds support for newer nested type/encoding capabilities (including map support) and 2.2-era storage features.
legacy	N/A	N/A	Alias for 0.1
stable	N/A	N/A	Alias for the latest stable version in the Lance release you are running.
next	N/A	N/A	Alias for the latest unstable version in the Lance release you are running.