fix: update default temp table expiration to 7 days (#174)

Author: tswast

bigframes/constants.py

@@ -26,4 +26,4 @@
 
 ABSTRACT_METHOD_ERROR_MESSAGE = f"Abstract method. You have likely encountered a bug. Please share this stacktrace and how you reached it with the BigQuery DataFrames team. {FEEDBACK_LINK}"
 
-DEFAULT_EXPIRATION = datetime.timedelta(days=1)
+DEFAULT_EXPIRATION = datetime.timedelta(days=7)

bigframes/dataframe.py

@@ -16,6 +16,7 @@
 
 from __future__ import annotations
 
+import datetime
 import re
 import textwrap
 import typing
@@ -2327,7 +2328,8 @@ def to_gbq(
                 self._session.bqclient,
                 self._session._anonymous_dataset,
                 # TODO(swast): allow custom expiration times, probably via session configuration.
-                constants.DEFAULT_EXPIRATION,
+                datetime.datetime.now(datetime.timezone.utc)
+                + constants.DEFAULT_EXPIRATION,
             )
 
             if if_exists is not None and if_exists != "replace":

bigframes/session/__init__.py

@@ -430,7 +430,9 @@ def _read_gbq_query(
             index_cols = list(index_col)
 
         destination, query_job = self._query_to_destination(
-            query, index_cols, api_name="read_gbq_query"
+            query,
+            index_cols,
+            api_name=api_name,
         )
 
         # If there was no destination table, that means the query must have

bigframes/session/_io/bigquery.py

@@ -14,6 +14,8 @@
 
 """Private module: Helpers for I/O operations."""
 
+from __future__ import annotations
+
 import datetime
 import textwrap
 import types
@@ -69,6 +71,29 @@ def create_export_data_statement(
     )
 
 
+def random_table(dataset: bigquery.DatasetReference) -> bigquery.TableReference:
+    """Generate a random table ID with BigQuery DataFrames prefix.
+    Args:
+        dataset (google.cloud.bigquery.DatasetReference):
+            The dataset to make the table reference in. Usually the anonymous
+            dataset for the session.
+    Returns:
+        google.cloud.bigquery.TableReference:
+            Fully qualified table ID of a table that doesn't exist.
+    """
+    now = datetime.datetime.now(datetime.timezone.utc)
+    random_id = uuid.uuid4().hex
+    table_id = TEMP_TABLE_PREFIX.format(
+        date=now.strftime("%Y%m%d"), random_id=random_id
+    )
+    return dataset.table(table_id)
+
+
+def table_ref_to_sql(table: bigquery.TableReference) -> str:
+    """Format a table reference as escaped SQL."""
+    return f"`{table.project}`.`{table.dataset_id}`.`{table.table_id}`"
+
+
 def create_snapshot_sql(
     table_ref: bigquery.TableReference, current_timestamp: datetime.datetime
 ) -> str:
@@ -95,17 +120,12 @@ def create_snapshot_sql(
 def create_temp_table(
     bqclient: bigquery.Client,
     dataset: bigquery.DatasetReference,
-    expiration: datetime.timedelta,
+    expiration: datetime.datetime,
 ) -> str:
     """Create an empty table with an expiration in the desired dataset."""
-    now = datetime.datetime.now(datetime.timezone.utc)
-    random_id = uuid.uuid4().hex
-    table_id = TEMP_TABLE_PREFIX.format(
-        date=now.strftime("%Y%m%d"), random_id=random_id
-    )
-    table_ref = dataset.table(table_id)
+    table_ref = random_table(dataset)
     destination = bigquery.Table(table_ref)
-    destination.expires = now + expiration
+    destination.expires = expiration
     bqclient.create_table(destination)
     return f"{table_ref.project}.{table_ref.dataset_id}.{table_ref.table_id}"
 

tests/unit/session/test_io_bigquery.py

@@ -56,9 +56,9 @@ def test_create_temp_table_default_expiration():
     """Make sure the created table has an expiration."""
     bqclient = mock.create_autospec(bigquery.Client)
     dataset = bigquery.DatasetReference("test-project", "test_dataset")
-    now = datetime.datetime.now(datetime.timezone.utc)
-    expiration = datetime.timedelta(days=3)
-    expected_expires = now + expiration
+    expiration = datetime.datetime(
+        2023, 11, 2, 13, 44, 55, 678901, datetime.timezone.utc
+    )
 
     bigframes.session._io.bigquery.create_temp_table(bqclient, dataset, expiration)
 
@@ -69,9 +69,9 @@ def test_create_temp_table_default_expiration():
     assert table.dataset_id == "test_dataset"
     assert table.table_id.startswith("bqdf")
     assert (
-        (expected_expires - datetime.timedelta(minutes=1))
+        (expiration - datetime.timedelta(minutes=1))
         < table.expires
-        < (expected_expires + datetime.timedelta(minutes=1))
+        < (expiration + datetime.timedelta(minutes=1))
     )