diff --git a/datasette/app.py b/datasette/app.py
index d5994e5e..bc5aaa74 100644
--- a/datasette/app.py
+++ b/datasette/app.py
@@ -116,6 +116,43 @@ async def favicon(request):
     return response.text("")
 
 
+class ConnectedDatabase:
+    def __init__(self, path=None, is_mutable=False, is_memory=False):
+        self.path = path
+        self.is_mutable = is_mutable
+        self.is_memory = is_memory
+        self.hash = None
+        self.size = None
+        if not self.is_mutable:
+            p = Path(path)
+            self.hash = inspect_hash(p)
+            self.size = p.stat().st_size
+
+    @property
+    def name(self):
+        if self.is_memory:
+            return ":memory:"
+        else:
+            return Path(self.path).stem
+
+    def __repr__(self):
+        tags = []
+        if self.is_mutable:
+            tags.append("mutable")
+        if self.is_memory:
+            tags.append("memory")
+        if self.hash:
+            tags.append("hash={}".format(self.hash))
+        if self.size is not None:
+            tags.append("size={}".format(self.size))
+        tags_str = ""
+        if tags:
+            tags_str = " ({})".format(", ".join(tags))
+        return "<ConnectedDatabase: {}{}>".format(
+            self.name, tags_str
+        )
+
+
 class Datasette:
 
     def __init__(
@@ -141,6 +178,18 @@ class Datasette:
             self.files = [MEMORY]
         elif memory:
             self.files = (MEMORY,) + self.files
+        self.databases = {}
+        for file in self.files:
+            path = file
+            is_memory = False
+            if file is MEMORY:
+                path = None
+                is_memory = True
+            db = ConnectedDatabase(path, is_mutable=path not in self.immutables, is_memory=is_memory)
+            if db.name in self.databases:
+                raise Exception("Multiple files with same stem: {}".format(db.name))
+            self.databases[db.name] = db
+        print(self.databases)
         self.cache_headers = cache_headers
         self.cors = cors
         self._inspect = inspect_data
@@ -419,17 +468,17 @@ class Datasette:
         def in_thread():
             conn = getattr(connections, db_name, None)
             if not conn:
-                info = self.inspect()[db_name]
-                if info["file"] == ":memory:":
+                db = self.databases[db_name]
+                if db.is_memory:
                     conn = sqlite3.connect(":memory:")
                 else:
                     # mode=ro or immutable=1?
-                    if info["file"] in self.immutables:
-                        qs = "immutable=1"
-                    else:
+                    if db.is_mutable:
                         qs = "mode=ro"
+                    else:
+                        qs = "immutable=1"
                     conn = sqlite3.connect(
-                        "file:{}?{}".format(info["file"], qs),
+                        "file:{}?{}".format(db.path, qs),
                         uri=True,
                         check_same_thread=False,
                     )
diff --git a/datasette/views/base.py b/datasette/views/base.py
index e79a46ec..8da51d65 100644
--- a/datasette/views/base.py
+++ b/datasette/views/base.py
@@ -156,14 +156,13 @@ class BaseView(RenderMixin):
         return r
 
     async def resolve_db_name(self, request, db_name, **kwargs):
-        databases = self.ds.inspect()
         hash = None
         name = None
         if "-" in db_name:
             # Might be name-and-hash, or might just be
             # a name with a hyphen in it
             name, hash = db_name.rsplit("-", 1)
-            if name not in databases:
+            if name not in self.ds.databases:
                 # Try the whole name
                 name = db_name
                 hash = None
@@ -171,11 +170,13 @@ class BaseView(RenderMixin):
             name = db_name
         # Verify the hash
         try:
-            info = databases[name]
+            db = self.ds.databases[name]
         except KeyError:
             raise NotFound("Database not found: {}".format(name))
 
-        expected = info["hash"][:HASH_LENGTH]
+        expected = "000"
+        if db.hash is not None:
+            expected = db.hash[:HASH_LENGTH]
         correct_hash_provided = (expected == hash)
 
         if not correct_hash_provided:
diff --git a/tests/fixtures.py b/tests/fixtures.py
index 81432e30..c3883fe7 100644
--- a/tests/fixtures.py
+++ b/tests/fixtures.py
@@ -29,6 +29,7 @@ def make_app_client(
     cors=False,
     config=None,
     filename="fixtures.db",
+    is_immutable=False,
 ):
     with tempfile.TemporaryDirectory() as tmpdir:
         filepath = os.path.join(tmpdir, filename)
@@ -48,7 +49,8 @@ def make_app_client(
             }
         )
         ds = Datasette(
-            [filepath],
+            [] if is_immutable else [filepath],
+            immutables=[filepath] if is_immutable else [],
             cors=cors,
             metadata=METADATA,
             plugins_dir=plugins_dir,
@@ -76,8 +78,8 @@ def app_client_no_files():
 @pytest.fixture(scope="session")
 def app_client_with_hash():
     yield from make_app_client(config={
-        'hash_urls': True
-    })
+        'hash_urls': True,
+    }, is_immutable=True)
 
 
 @pytest.fixture(scope='session')
diff --git a/tests/test_api.py b/tests/test_api.py
index b92b9ffb..6fdcb115 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -1317,10 +1317,10 @@ def test_ttl_parameter(app_client, path, expected_cache_control):
     ("/fixtures/facetable.json?_hash=1", "/fixtures-HASH/facetable.json"),
     ("/fixtures/facetable.json?city_id=1&_hash=1", "/fixtures-HASH/facetable.json?city_id=1"),
 ])
-def test_hash_parameter(app_client, path, expected_redirect):
+def test_hash_parameter(app_client_with_hash, path, expected_redirect):
     # First get the current hash for the fixtures database
-    current_hash = app_client.get("/-/inspect.json").json["fixtures"]["hash"][:7]
-    response = app_client.get(path, allow_redirects=False)
+    current_hash = app_client_with_hash.get("/-/inspect.json").json["fixtures"]["hash"][:7]
+    response = app_client_with_hash.get(path, allow_redirects=False)
     assert response.status == 302
     location = response.headers["Location"]
     assert expected_redirect.replace("HASH", current_hash) == location