fix cluster type filter, test

Author: TrevorBergeron

bigframes/session/bq_caching_executor.py

@@ -643,7 +643,12 @@ def _execute_plan_gbq(
                 plan = nodes.PromoteOffsetsNode(plan, offsets_id)
                 cluster_cols = [offsets_id.sql]
             else:
-                cluster_cols = cache_spec.cluster_cols[:_MAX_CLUSTER_COLUMNS]
+                cluster_cols = [
+                    col
+                    for col in cache_spec.cluster_cols
+                    if bigframes.dtypes.is_clusterable(plan.schema.get_type(col))
+                ]
+                cluster_cols = cluster_cols[:_MAX_CLUSTER_COLUMNS]
 
         compiled = compile.compile_sql(
             compile.CompileRequest(

tests/system/small/test_dataframe.py

@@ -5540,7 +5540,7 @@ def test_df_cached(scalars_df_index):
 def test_df_cached_many_index_cols(scalars_df_index):
     index_cols = [
         "int64_too",
-        "geography_col",
+        "time_col",
         "int64_col",
         "bool_col",
         "date_col",