Add per-table suggest_facets configuration option

Allow disabling suggested facets for individual tables by setting
"suggest_facets": false in table configuration. This is useful for
tables where facet suggestions are unhelpful or too expensive, while
keeping them enabled for other tables in the same instance.

https://claude.ai/code/session_01JkWNePDCxMYKcq5qSfMo3r

datasette/utils/__init__.py

@@ -1443,6 +1443,7 @@ _table_config_keys = (
     "fts_table",
     "fts_pk",
     "searchmode",
+    "suggest_facets",
 )
 
 

datasette/views/table.py

@@ -1378,7 +1378,9 @@ async def table_view_data(
         suggested_facets = []
         # Calculate suggested facets
         if (
-            datasette.setting("suggest_facets")
+            table_metadata.get(
+                "suggest_facets", datasette.setting("suggest_facets")
+            )
             and datasette.setting("allow_facet")
             and not _next
             and not nofacet

docs/facets.rst

@@ -254,6 +254,55 @@ For the currently filtered data are there any columns which, if applied as a fac
 That last point is particularly important: Datasette runs a query for every column that is displayed on a page, which could get expensive - so to avoid slow load times it sets a time limit of just 50ms for each of those queries.
 This means suggested facets are unlikely to appear for tables with millions of records in them.
 
+You can turn off suggested facets for a specific table by setting ``"suggest_facets"`` to ``false`` in the table's configuration:
+
+.. [[[cog
+    from metadata_doc import metadata_example
+    metadata_example(cog, {
+      "databases": {
+        "mydb": {
+          "tables": {
+            "big_table": {
+              "suggest_facets": False
+            }
+          }
+        }
+      }
+    })
+.. ]]]
+
+.. tab:: metadata.yaml
+
+    .. code-block:: yaml
+
+        databases:
+          mydb:
+            tables:
+              big_table:
+                suggest_facets: false
+
+
+.. tab:: metadata.json
+
+    .. code-block:: json
+
+        {
+          "databases": {
+            "mydb": {
+              "tables": {
+                "big_table": {
+                  "suggest_facets": false
+                }
+              }
+            }
+          }
+        }
+.. [[[end]]]
+
+This will disable suggested facets for that table only. Other tables in the same database will continue to suggest facets as normal. Explicitly requested facets (using ``?_facet=column``) will still work.
+
+You can also disable suggested facets for the entire Datasette instance using the :ref:`setting_suggest_facets` setting.
+
 Speeding up facets with indexes
 -------------------------------
 

tests/test_table_api.py

@@ -1002,6 +1002,39 @@ def test_suggest_facets_off():
         )
 
 
+def test_suggest_facets_off_per_table():
+    with make_app_client(
+        metadata={
+            "databases": {
+                "fixtures": {
+                    "tables": {
+                        "facetable": {"suggest_facets": False},
+                    }
+                }
+            }
+        }
+    ) as client:
+        # suggested_facets should be [] for the table with suggest_facets: false
+        assert (
+            []
+            == client.get("/fixtures/facetable.json?_extra=suggested_facets").json[
+                "suggested_facets"
+            ]
+        )
+        # But other tables should still get suggestions
+        other = client.get(
+            "/fixtures/simple_primary_key.json?_extra=suggested_facets"
+        ).json["suggested_facets"]
+        # simple_primary_key has a 'content' column that can be faceted
+        assert isinstance(other, list)
+        # Explicit facets should still work even when suggestions are off
+        response = client.get(
+            "/fixtures/facetable.json?_facet=state&_extra=suggested_facets"
+        )
+        assert response.json["suggested_facets"] == []
+        assert response.json["facet_results"]["results"] != {}
+
+
 @pytest.mark.asyncio
 @pytest.mark.parametrize("nofacet", (True, False))
 async def test_nofacet(ds_client, nofacet):