Revert "snapshot update"

This reverts commit 123a50e.

Author: shuoweil

bigframes/dataframe.py

@@ -2288,13 +2288,8 @@ def _assign_scalar(self, label: str, value: Union[int, float, str]) -> DataFrame
     def _assign_series_join_on_index(
         self, label: str, series: bigframes.series.Series
     ) -> DataFrame:
-        # Only use block_identity_join for null indices
-        use_block_identity_join = (
-            self._block.index.nlevels == 0 and series._block.index.nlevels == 0
-        )
-
         block, (get_column_left, get_column_right) = self._block.join(
-            series._block, how="left", block_identity_join=use_block_identity_join
+            series._block, how="left", block_identity_join=True
         )
 
         column_ids = [

tests/unit/core/compile/sqlglot/expressions/snapshots/test_binary_compiler/test_add_numeric/out.sql

@@ -1,42 +1,16 @@
-WITH `bfcte_1` AS (
+WITH `bfcte_0` AS (
   SELECT
-    `rowindex` AS `bfcol_0`
+    `int64_col` AS `bfcol_0`,
+    `rowindex` AS `bfcol_1`
   FROM `bigframes-dev`.`sqlglot_test`.`scalar_types`
-), `bfcte_4` AS (
-  SELECT
-    `bfcol_0` AS `bfcol_1`
-  FROM `bfcte_1`
-), `bfcte_0` AS (
-  SELECT
-    `int64_col` AS `bfcol_2`,
-    `rowindex` AS `bfcol_3`
-  FROM `bigframes-dev`.`sqlglot_test`.`scalar_types`
-), `bfcte_2` AS (
+), `bfcte_1` AS (
   SELECT
     *,
-    `bfcol_3` AS `bfcol_6`,
-    `bfcol_2` AS `bfcol_7`,
-    `bfcol_2` AS `bfcol_8`
+    `bfcol_1` AS `bfcol_4`,
+    `bfcol_0` + `bfcol_0` AS `bfcol_5`
   FROM `bfcte_0`
-), `bfcte_3` AS (
-  SELECT
-    *,
-    `bfcol_7` + `bfcol_8` AS `bfcol_12`
-  FROM `bfcte_2`
-), `bfcte_5` AS (
-  SELECT
-    `bfcol_6` AS `bfcol_13`,
-    `bfcol_12` AS `bfcol_14`
-  FROM `bfcte_3`
-), `bfcte_6` AS (
-  SELECT
-    *
-  FROM `bfcte_4`
-  LEFT JOIN `bfcte_5`
-    ON COALESCE(`bfcol_1`, 0) = COALESCE(`bfcol_13`, 0)
-    AND COALESCE(`bfcol_1`, 1) = COALESCE(`bfcol_13`, 1)
 )
 SELECT
-  `bfcol_1` AS `rowindex`,
-  `bfcol_14` AS `int64_col`
-FROM `bfcte_6`
+  `bfcol_4` AS `rowindex`,
+  `bfcol_5` AS `int64_col`
+FROM `bfcte_1`