feat: support remote empty query (#1828)

Support sending empty query types to remote lancedb. also include offset
and limit, where were previously omitted.

python/python/tests/test_remote_db.py

@@ -197,6 +197,23 @@ def test_query_sync_minimal():
         assert data == expected
 
 
+def test_query_sync_empty_query():
+    def handler(body):
+        assert body == {
+            "k": 10,
+            "filter": "true",
+            "vector": [],
+            "columns": ["id"],
+        }
+
+        return pa.table({"id": [1, 2, 3]})
+
+    with query_test_table(handler) as table:
+        data = table.search(None).where("true").select(["id"]).limit(10).to_list()
+        expected = [{"id": 1}, {"id": 2}, {"id": 3}]
+        assert data == expected
+
+
 def test_query_sync_maximal():
     def handler(body):
         assert body == {

python/python/tests/test_table.py

@@ -892,10 +892,15 @@ def test_empty_query(db):
     table = LanceTable.create(db, "my_table2", data=[{"id": i} for i in range(100)])
     df = table.search().select(["id"]).to_pandas()
     assert len(df) == 10
+    # None is the same as default
     df = table.search().select(["id"]).limit(None).to_pandas()
-    assert len(df) == 100
+    assert len(df) == 10
+    # invalid limist is the same as None, wihch is the same as default
     df = table.search().select(["id"]).limit(-1).to_pandas()
-    assert len(df) == 100
+    assert len(df) == 10
+    # valid limit should work
+    df = table.search().select(["id"]).limit(42).to_pandas()
+    assert len(df) == 42
 
 
 def test_search_with_schema_inf_single_vector(db):