feat(bigtable): support materialized views in the data client

Adds a MaterializedView class (async and sync) to the Bigtable data
client, alongside Table and AuthorizedView, plus a
client.get_materialized_view() factory. Materialized views are
instance-scoped and read-only: read_rows and sample_row_keys route
requests via materialized_view_name, while mutation methods raise
NotImplementedError since the mutation RPCs cannot target a
materialized view.

To support targets without a backing table, table identity
(table_id/table_name) moves from the shared _DataApiTarget base class
into the Table and AuthorizedView subclasses.

Author: axyjo

packages/google-cloud-bigtable/docs/data_client/async_data_materialized_view.rst

@@ -0,0 +1,11 @@
+Materialized View Async
+~~~~~~~~~~~~~~~~~~~~~~~
+
+    .. note::
+
+      It is generally not recommended to use the async client in an otherwise synchronous codebase. To make use of asyncio's
+      performance benefits, the codebase should be designed to be async from the ground up.
+
+.. autoclass:: google.cloud.bigtable.data._async.client.MaterializedViewAsync
+  :members:
+  :inherited-members:

packages/google-cloud-bigtable/docs/data_client/data_client_usage.rst

@@ -10,6 +10,7 @@ Sync Surface
   sync_data_client
   sync_data_table
   sync_data_authorized_view
+  sync_data_materialized_view
   sync_data_mutations_batcher
   sync_data_execute_query_iterator
 
@@ -22,6 +23,7 @@ Async Surface
   async_data_client
   async_data_table
   async_data_authorized_view
+  async_data_materialized_view
   async_data_mutations_batcher
   async_data_execute_query_iterator
 

packages/google-cloud-bigtable/docs/data_client/sync_data_materialized_view.rst

@@ -0,0 +1,6 @@
+Materialized View
+~~~~~~~~~~~~~~~~~
+
+.. autoclass:: google.cloud.bigtable.data._sync_autogen.client.MaterializedView
+  :members:
+  :inherited-members:

packages/google-cloud-bigtable/google/cloud/bigtable/data/__init__.py

@@ -19,6 +19,7 @@
 from google.cloud.bigtable.data._async.client import (
     AuthorizedViewAsync,
     BigtableDataClientAsync,
+    MaterializedViewAsync,
     TableAsync,
 )
 from google.cloud.bigtable.data._async.mutations_batcher import MutationsBatcherAsync
@@ -33,6 +34,7 @@
 from google.cloud.bigtable.data._sync_autogen.client import (
     AuthorizedView,
     BigtableDataClient,
+    MaterializedView,
     Table,
 )
 from google.cloud.bigtable.data._sync_autogen.mutations_batcher import MutationsBatcher
@@ -80,10 +82,12 @@
     "BigtableDataClientAsync",
     "TableAsync",
     "AuthorizedViewAsync",
+    "MaterializedViewAsync",
     "MutationsBatcherAsync",
     "BigtableDataClient",
     "Table",
     "AuthorizedView",
+    "MaterializedView",
     "MutationsBatcher",
     "RowKeySamples",
     "ReadRowsQuery",