fix saas open_table and table_names issues (#640)

- added check whether a table exists in SaaS open_table
- remove prefilter not supported warning in SaaS search
- fixed issues for SaaS table_names

python/lancedb/remote/client.py

@@ -155,13 +155,10 @@ class RestfulLanceDBClient:
         self, limit: int, page_token: Optional[str] = None
     ) -> Iterable[str]:
         """List all tables in the database."""
-        try:
-            json = await self.get(
-                "/v1/table/", {"limit": limit, "page_token": page_token}
-            )
-            return json["tables"]
-        except StopAsyncIteration:
-            return []
+        if page_token is None:
+            page_token = ""
+        json = await self.get("/v1/table/", {"limit": limit, "page_token": page_token})
+        return json["tables"]
 
     @_check_not_closed
     async def query(self, table_name: str, query: VectorQuery) -> VectorQueryResult:

python/lancedb/remote/db.py

@@ -13,6 +13,7 @@
 
 import asyncio
 import inspect
+import logging
 import uuid
 from typing import Iterable, List, Optional, Union
 from urllib.parse import urlparse
@@ -62,7 +63,7 @@ class RemoteDBConnection(DBConnection):
 
         Parameters
         ----------
-        last_token: str
+        page_token: str
             The last token to start the new page.
 
         Returns
@@ -95,8 +96,16 @@ class RemoteDBConnection(DBConnection):
         """
         from .table import RemoteTable
 
-        # TODO: check if table exists
-
+        # check if table exists
+        try:
+            self._loop.run_until_complete(
+                self._client.post(f"/v1/table/{name}/describe/")
+            )
+        except Exception:
+            logging.error(
+                "Table {name} does not exist."
+                "Please first call db.create_table({name}, data)"
+            )
         return RemoteTable(self, name)
 
     @override

python/lancedb/remote/table.py

@@ -99,8 +99,6 @@ class RemoteTable(Table):
         return LanceVectorQueryBuilder(self, query, vector_column_name)
 
     def _execute_query(self, query: Query) -> pa.Table:
-        if query.prefilter:
-            raise NotImplementedError("Cloud support for prefiltering is coming soon")
         result = self._conn._client.query(self._name, query)
         return self._conn._loop.run_until_complete(result).to_arrow()