feat: add estimated number of rows to CreateReadSession response (#542)

* feat: add estimated number of rows to CreateReadSession response

PiperOrigin-RevId: 495122850

Source-Link: googleapis/googleapis@83b2baf

Source-Link: googleapis/googleapis-gen@6720765
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google/cloud/bigquery_storage_v1/types/stream.py

@@ -105,6 +105,11 @@ class ReadSession(proto.Message):
             are completely consumed. This estimate is based
             on metadata from the table which might be
             incomplete or stale.
+        estimated_row_count (int):
+            Output only. An estimate on the number of
+            rows present in this session's streams. This
+            estimate is based on metadata from the table
+            which might be incomplete or stale.
         trace_id (str):
             Optional. ID set by client to annotate a
             session identity.  This does not need to be
@@ -268,6 +273,10 @@ class TableReadOptions(proto.Message):
         proto.INT64,
         number=12,
     )
+    estimated_row_count: int = proto.Field(
+        proto.INT64,
+        number=14,
+    )
     trace_id: str = proto.Field(
         proto.STRING,
         number=13,

tests/unit/gapic/bigquery_storage_v1/test_big_query_read.py

@@ -702,6 +702,7 @@ def test_create_read_session(request_type, transport: str = "grpc"):
             data_format=stream.DataFormat.AVRO,
             table="table_value",
             estimated_total_bytes_scanned=3076,
+            estimated_row_count=2047,
             trace_id="trace_id_value",
             avro_schema=avro.AvroSchema(schema="schema_value"),
         )
@@ -718,6 +719,7 @@ def test_create_read_session(request_type, transport: str = "grpc"):
     assert response.data_format == stream.DataFormat.AVRO
     assert response.table == "table_value"
     assert response.estimated_total_bytes_scanned == 3076
+    assert response.estimated_row_count == 2047
     assert response.trace_id == "trace_id_value"
 
 
@@ -763,6 +765,7 @@ async def test_create_read_session_async(
                 data_format=stream.DataFormat.AVRO,
                 table="table_value",
                 estimated_total_bytes_scanned=3076,
+                estimated_row_count=2047,
                 trace_id="trace_id_value",
             )
         )
@@ -779,6 +782,7 @@ async def test_create_read_session_async(
     assert response.data_format == stream.DataFormat.AVRO
     assert response.table == "table_value"
     assert response.estimated_total_bytes_scanned == 3076
+    assert response.estimated_row_count == 2047
     assert response.trace_id == "trace_id_value"