perf(api): add multi-column GIN index on findings array fields (#11001)

api/src/backend/api/migrations/0091_findings_arrays_gin_index_partitions.py

@@ -0,0 +1,31 @@
+from functools import partial
+
+from django.db import migrations
+
+from api.db_utils import create_index_on_partitions, drop_index_on_partitions
+
+
+class Migration(migrations.Migration):
+    atomic = False
+
+    dependencies = [
+        ("api", "0090_attack_paths_cleanup_priority"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            partial(
+                create_index_on_partitions,
+                parent_table="findings",
+                index_name="gin_find_arrays_idx",
+                columns="categories, resource_services, resource_regions, resource_types",
+                method="GIN",
+                all_partitions=True,
+            ),
+            reverse_code=partial(
+                drop_index_on_partitions,
+                parent_table="findings",
+                index_name="gin_find_arrays_idx",
+            ),
+        )
+    ]

api/src/backend/api/migrations/0092_findings_arrays_gin_index_parent.py

@@ -0,0 +1,58 @@
+import django.contrib.postgres.indexes
+from django.db import migrations
+
+INDEX_NAME = "gin_find_arrays_idx"
+PARENT_TABLE = "findings"
+
+
+def create_parent_and_attach(apps, schema_editor):
+    with schema_editor.connection.cursor() as cursor:
+        cursor.execute(
+            f"CREATE INDEX {INDEX_NAME} ON ONLY {PARENT_TABLE} "
+            f"USING gin (categories, resource_services, resource_regions, resource_types)"
+        )
+        cursor.execute(
+            "SELECT inhrelid::regclass::text "
+            "FROM pg_inherits "
+            "WHERE inhparent = %s::regclass",
+            [PARENT_TABLE],
+        )
+        for (partition,) in cursor.fetchall():
+            child_idx = f"{partition.replace('.', '_')}_{INDEX_NAME}"
+            cursor.execute(f"ALTER INDEX {INDEX_NAME} ATTACH PARTITION {child_idx}")
+
+
+def drop_parent_index(apps, schema_editor):
+    with schema_editor.connection.cursor() as cursor:
+        cursor.execute(f"DROP INDEX IF EXISTS {INDEX_NAME}")
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("api", "0091_findings_arrays_gin_index_partitions"),
+    ]
+
+    operations = [
+        migrations.SeparateDatabaseAndState(
+            state_operations=[
+                migrations.AddIndex(
+                    model_name="finding",
+                    index=django.contrib.postgres.indexes.GinIndex(
+                        fields=[
+                            "categories",
+                            "resource_services",
+                            "resource_regions",
+                            "resource_types",
+                        ],
+                        name=INDEX_NAME,
+                    ),
+                ),
+            ],
+            database_operations=[
+                migrations.RunPython(
+                    create_parent_and_attach,
+                    reverse_code=drop_parent_index,
+                ),
+            ],
+        ),
+    ]

api/src/backend/api/models.py

@@ -946,7 +946,6 @@ class Resource(RowLevelSecurityProtectedModel):
                 OpClass(Upper("name"), name="gin_trgm_ops"),
                 name="res_name_trgm_idx",
             ),
-            GinIndex(fields=["text_search"], name="gin_resources_search_idx"),
             models.Index(fields=["tenant_id", "id"], name="resources_tenant_id_idx"),
             models.Index(
                 fields=["tenant_id", "provider_id"],
@@ -1152,6 +1151,15 @@ class Finding(PostgresPartitionedModel, RowLevelSecurityProtectedModel):
                 fields=["tenant_id", "scan_id", "check_id"],
                 name="find_tenant_scan_check_idx",
             ),
+            GinIndex(
+                fields=[
+                    "categories",
+                    "resource_services",
+                    "resource_regions",
+                    "resource_types",
+                ],
+                name="gin_find_arrays_idx",
+            ),
         ]
 
     class JSONAPIMeta: