fix: remove primary key constraint from MemWAL bucket sharding

Lance v7.0.0-rc.1 intentionally removed the requirement for
bucket_sharding to match (or even require) the unenforced primary key
column. Update LanceDB to match: drop the PK-related doc comments and
the test assertions that expected rejection when no PK is set or when
the bucket column differs from the PK.

The Rust changes are taken from #3435; this commit additionally applies
the equivalent updates to the Python and TypeScript bindings.

See https://github.com/lance-format/lance/issues/6917

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

python/python/lancedb/table.py

@@ -3875,15 +3875,11 @@ class AsyncTable:
         strategies:
 
         - ``LsmWriteSpec.bucket(column, num_buckets)`` — hash-bucket writes by
-          the single-column unenforced primary key.
+          a scalar column.
         - ``LsmWriteSpec.identity(column)`` — shard by the raw value of a
           scalar column.
         - ``LsmWriteSpec.unsharded()`` — route every write to a single shard.
 
-        All variants require the table to have an unenforced primary key set
-        via [`set_unenforced_primary_key`]; bucket sharding additionally
-        requires it to be the single column being bucketed.
-
         Parameters
         ----------
         spec : LsmWriteSpec
@@ -3892,7 +3888,6 @@ class AsyncTable:
         Examples
         --------
         >>> from lancedb._lancedb import LsmWriteSpec
-        >>> # table.set_unenforced_primary_key("id")
         >>> # table.set_lsm_write_spec(LsmWriteSpec.bucket("id", 16))
         """
         await self._inner.set_lsm_write_spec(spec)

python/python/tests/test_lsm_write_spec.py

@@ -40,16 +40,6 @@ def _make_table(tmp_path):
 def test_set_lsm_write_spec_validates(tmp_path):
     _db, table = _make_table(tmp_path)
 
-    # No PK set yet.
-    with pytest.raises(Exception, match="primary key"):
-        table.set_lsm_write_spec(LsmWriteSpec.bucket("id", 4))
-
-    table.set_unenforced_primary_key("id")
-
-    # Column mismatch.
-    with pytest.raises(Exception, match="match"):
-        table.set_lsm_write_spec(LsmWriteSpec.bucket("v", 4))
-
     # Out-of-range num_buckets.
     with pytest.raises(Exception, match="num_buckets"):
         table.set_lsm_write_spec(LsmWriteSpec.bucket("id", 0))
@@ -70,7 +60,6 @@ def test_unset_lsm_write_spec(tmp_path):
         table.unset_lsm_write_spec()
 
     # Install a spec, then remove it; afterwards a fresh spec can be set.
-    table.set_unenforced_primary_key("id")
     table.set_lsm_write_spec(LsmWriteSpec.bucket("id", 4))
     table.unset_lsm_write_spec()
     # A second unset errors — there is no spec left to remove.
@@ -81,9 +70,7 @@ def test_unset_lsm_write_spec(tmp_path):
 
 def test_set_unsharded_spec(tmp_path):
     _db, table = _make_table(tmp_path)
-    # Lance MemWAL still requires a primary key on the dataset; Unsharded
-    # just skips per-row hashing.
-    table.set_unenforced_primary_key("id")
+    # Unsharded routes every write to a single shard, skipping per-row hashing.
     table.set_lsm_write_spec(LsmWriteSpec.unsharded())
     table.unset_lsm_write_spec()
 
@@ -120,7 +107,6 @@ async def test_async_set_unset_lsm_write_spec(tmp_path):
         pa.RecordBatchReader.from_batches(SCHEMA, [_batch(["seed"], [0])]),
     )
 
-    await table.set_unenforced_primary_key("id")
     await table.set_lsm_write_spec(LsmWriteSpec.bucket("id", 4))
     await table.unset_lsm_write_spec()
     # A second unset errors.
@@ -130,9 +116,7 @@ async def test_async_set_unset_lsm_write_spec(tmp_path):
 
 def test_set_identity_spec(tmp_path):
     _db, table = _make_table(tmp_path)
-    # Identity sharding still requires an unenforced primary key on the
-    # table; it shards by the raw value of the given column.
-    table.set_unenforced_primary_key("id")
+    # Identity sharding shards by the raw value of the given column.
     table.set_lsm_write_spec(LsmWriteSpec.identity("v"))
     table.unset_lsm_write_spec()
 

python/src/table.rs

@@ -185,7 +185,7 @@ pub struct LsmWriteSpec {
 
 #[pymethods]
 impl LsmWriteSpec {
-    /// Hash-bucket sharding by the unenforced primary key column.
+    /// Hash-bucket sharding by a scalar column.
     #[staticmethod]
     pub fn bucket(column: String, num_buckets: u32) -> Self {
         Self {