diff --git a/swh/provenance/graph.py b/swh/provenance/graph.py
index cc2a92d..4e77eb6 100644
--- a/swh/provenance/graph.py
+++ b/swh/provenance/graph.py
@@ -1,275 +1,257 @@
 # Copyright (C) 2021  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 from __future__ import annotations
 
 from datetime import datetime, timezone
 import os
 from typing import Any, Dict, Optional, Set
 
 from swh.core.statsd import statsd
 from swh.model.hashutil import hash_to_hex
 from swh.model.model import Sha1Git
 
 from .archive import ArchiveInterface
 from .interface import ProvenanceInterface
 from .model import DirectoryEntry, RevisionEntry
 
 GRAPH_DURATION_METRIC = "swh_provenance_graph_duration_seconds"
 GRAPH_OPERATIONS_METRIC = "swh_provenance_graph_operations_total"
 
 UTCMIN = datetime.min.replace(tzinfo=timezone.utc)
 
 
 class HistoryNode:
     def __init__(
         self, entry: RevisionEntry, is_head: bool = False, in_history: bool = False
     ) -> None:
         self.entry = entry
         # A revision is `is_head` if it is directly pointed by an origin (ie. a head
         # revision for some snapshot)
         self.is_head = is_head
         # A revision is `in_history` if it appears in the history graph of an already
         # processed revision in the provenance database
         self.in_history = in_history
         # XXX: the current simplified version of the origin-revision layer algorithm
         # does not use this previous two flags at all. They are kept for now but might
         # be removed in the future (hence, RevisionEntry might be used instead of
         # HistoryNode).
 
     def __str__(self) -> str:
         return f"<{self.entry}: is_head={self.is_head}, in_history={self.in_history}>"
 
     def as_dict(self) -> Dict[str, Any]:
         return {
             "rev": hash_to_hex(self.entry.id),
             "is_head": self.is_head,
             "in_history": self.in_history,
         }
 
 
 class HistoryGraph:
     @statsd.timed(metric=GRAPH_DURATION_METRIC, tags={"method": "build_history_graph"})
     def __init__(
         self,
         provenance: ProvenanceInterface,
         archive: ArchiveInterface,
         revision: RevisionEntry,
     ) -> None:
         self._head = HistoryNode(
             revision,
             is_head=provenance.revision_visited(revision),
             in_history=provenance.revision_in_history(revision),
         )
         self._graph: Dict[HistoryNode, Set[HistoryNode]] = {}
 
         stack = [self._head]
         while stack:
             current = stack.pop()
 
             if current not in self._graph:
                 self._graph[current] = set()
                 current.entry.retrieve_parents(archive)
                 for parent in current.entry.parents:
                     node = HistoryNode(
                         parent,
                         is_head=provenance.revision_visited(parent),
                         in_history=provenance.revision_in_history(parent),
                     )
                     self._graph[current].add(node)
                     stack.append(node)
 
     @property
     def head(self) -> HistoryNode:
         return self._head
 
     @property
     def parents(self) -> Dict[HistoryNode, Set[HistoryNode]]:
         return self._graph
 
     def __str__(self) -> str:
         return f"<HistoryGraph: head={self._head}, graph={self._graph}"
 
     def as_dict(self) -> Dict[str, Any]:
         return {
             "head": self.head.as_dict(),
             "graph": {
                 hash_to_hex(node.entry.id): sorted(
                     [parent.as_dict() for parent in parents],
                     key=lambda d: d["rev"],
                 )
                 for node, parents in self._graph.items()
             },
         }
 
 
 class IsochroneNode:
     def __init__(
         self,
         entry: DirectoryEntry,
         dbdate: Optional[datetime] = None,
         depth: int = 0,
         prefix: bytes = b"",
     ) -> None:
         self.entry = entry
         self.depth = depth
 
         # dbdate is the maxdate for this node that comes from the DB
         self._dbdate: Optional[datetime] = dbdate
 
         # maxdate is set by the maxdate computation algorithm
         self.maxdate: Optional[datetime] = None
 
-        # known is True if this node is already known in the db; either because
-        # the current directory actually exists in the database, or because all
-        # the content of the current directory is known (subdirectories and files)
-        self.known = self.dbdate is not None
         self.invalid = False
         self.path = os.path.join(prefix, self.entry.name) if prefix else self.entry.name
         self.children: Set[IsochroneNode] = set()
 
     @property
     def dbdate(self) -> Optional[datetime]:
         # use a property to make this attribute (mostly) read-only
         return self._dbdate
 
     def invalidate(self) -> None:
         statsd.increment(
             metric=GRAPH_OPERATIONS_METRIC, tags={"method": "invalidate_frontier"}
         )
         self._dbdate = None
         self.maxdate = None
-        self.known = False
         self.invalid = True
 
     def add_directory(
         self, child: DirectoryEntry, date: Optional[datetime] = None
     ) -> IsochroneNode:
         # we should not be processing this node (ie add subdirectories or files) if it's
         # actually known by the provenance DB
         assert self.dbdate is None
         node = IsochroneNode(child, dbdate=date, depth=self.depth + 1, prefix=self.path)
         self.children.add(node)
         return node
 
     def __str__(self) -> str:
         return (
-            f"<{self.entry}: depth={self.depth}, "
-            f"dbdate={self.dbdate}, maxdate={self.maxdate}, "
-            f"known={self.known}, invalid={self.invalid}, path={self.path!r}, "
+            f"<{self.entry}: depth={self.depth}, dbdate={self.dbdate}, "
+            f"maxdate={self.maxdate}, invalid={self.invalid}, path={self.path!r}, "
             f"children=[{', '.join(str(child) for child in self.children)}]>"
         )
 
     def __eq__(self, other: Any) -> bool:
         return isinstance(other, IsochroneNode) and self.__dict__ == other.__dict__
 
     def __hash__(self) -> int:
         # only immutable attributes are considered to compute hash
         return hash((self.entry, self.depth, self.path))
 
 
 @statsd.timed(metric=GRAPH_DURATION_METRIC, tags={"method": "build_isochrone_graph"})
 def build_isochrone_graph(
     provenance: ProvenanceInterface,
     archive: ArchiveInterface,
     revision: RevisionEntry,
     directory: DirectoryEntry,
     minsize: int = 0,
 ) -> IsochroneNode:
     assert revision.date is not None
     assert revision.root == directory.id
 
     # this function process a revision in 2 steps:
     #
     # 1. build the tree structure of IsochroneNode objects (one INode per
     #    directory under the root directory of the revision but not following
     #    known subdirectories), and gather the dates from the DB for already
     #    known objects; for files, just keep all the dates in a global 'fdates'
     #    dict; note that in this step, we will only recurse the directories
     #    that are not already known.
     #
     # 2. compute the maxdate for each node of the tree that was not found in the DB.
 
     # Build the nodes structure
     root_date = provenance.directory_get_date_in_isochrone_frontier(directory)
     root = IsochroneNode(directory, dbdate=root_date)
     stack = [root]
     fdates: Dict[Sha1Git, datetime] = {}  # map {file_id: date}
     while stack:
         current = stack.pop()
         if current.dbdate is None or current.dbdate >= revision.date:
             # If current directory has an associated date in the isochrone frontier that
             # is greater or equal to the current revision's one, it should be ignored as
             # the revision is being processed out of order.
             if current.dbdate is not None and current.dbdate >= revision.date:
                 current.invalidate()
 
             # Pre-query all known dates for directories in the current directory
             # for the provenance object to have them cached and (potentially) improve
             # performance.
             current.entry.retrieve_children(archive, minsize=minsize)
             ddates = provenance.directory_get_dates_in_isochrone_frontier(
                 current.entry.dirs
             )
             for dir in current.entry.dirs:
                 # Recursively analyse subdirectory nodes
                 node = current.add_directory(dir, date=ddates.get(dir.id, None))
                 stack.append(node)
 
             fdates.update(provenance.content_get_early_dates(current.entry.files))
 
     # Precalculate max known date for each node in the graph (only directory nodes are
     # pushed to the stack).
     stack = [root]
 
     while stack:
         current = stack.pop()
         # Current directory node is known if it already has an assigned date (ie. it was
         # already seen as an isochrone frontier).
-        if current.known:
+        if current.dbdate is not None:
             assert current.maxdate is None
             current.maxdate = current.dbdate
         else:
             if any(x.maxdate is None for x in current.children):
                 # at least one child of current has no maxdate yet
                 # Current node needs to be analysed again after its children.
                 stack.append(current)
                 for child in current.children:
                     if child.maxdate is None:
                         # if child.maxdate is None, it must be processed
                         stack.append(child)
             else:
                 # all the files and directories under current have a maxdate,
                 # we can infer the maxdate for current directory
                 assert current.maxdate is None
                 # if all content is already known, update current directory info.
-                current.maxdate = max(
-                    [UTCMIN]
-                    + [
-                        child.maxdate
-                        for child in current.children
-                        if child.maxdate is not None  # unnecessary, but needed for mypy
-                    ]
-                    + [
-                        fdates.get(file.id, revision.date)
-                        for file in current.entry.files
-                    ]
+                current.maxdate = min(
+                    max(
+                        [UTCMIN]
+                        + [
+                            child.maxdate
+                            for child in current.children
+                            if child.maxdate is not None  # for mypy
+                        ]
+                        + [
+                            fdates.get(file.id, revision.date)
+                            for file in current.entry.files
+                        ]
+                    ),
+                    revision.date,
                 )
-                if current.maxdate <= revision.date:
-                    current.known = (
-                        # true if all subdirectories are known
-                        all(child.known for child in current.children)
-                        # true if all files are in fdates, i.e. if all files were known
-                        # *before building this isochrone graph node*
-                        # Note: the 'all()' is lazy: will stop iterating as soon as
-                        # possible
-                        and all((file.id in fdates) for file in current.entry.files)
-                    )
-                else:
-                    # at least one content is being processed out-of-order, then current
-                    # node should be treated as unknown
-                    current.maxdate = revision.date
-                    current.known = False
     return root
diff --git a/swh/provenance/tests/data/graphs_cmdbts2_lower_1.yaml b/swh/provenance/tests/data/graphs_cmdbts2_lower_1.yaml
index 2b2f523..b3dd843 100644
--- a/swh/provenance/tests/data/graphs_cmdbts2_lower_1.yaml
+++ b/swh/provenance/tests/data/graphs_cmdbts2_lower_1.yaml
@@ -1,401 +1,370 @@
 # Isochrone graph for R00
 - rev: "c0d8929936631ecbcf9147be6b8aa13b13b014e4"
   graph:
     entry:
       id: "a4cb5e6b2831f7e8eef0e6e08e43d642c97303a1"
       name: ""
     maxdate: 1000000000.0
     path: ""
     children:
       - entry:
           id: "1c8d9fd9afa7e5a2cf52a3db6f05dc5c3a1ca86b"
           name: "A"
         maxdate: 1000000000.0
         path: "A"
         children:
           - entry:
               id: "36876d475197b5ad86ad592e8e28818171455f16"
               name: "B"
             maxdate: 1000000000.0
             path: "A/B"
             children:
               - entry:
                   id: "98f7a4a23d8df1fb1a5055facae2aff9b2d0a8b3"
                   name: "C"
                 maxdate: 1000000000.0
                 path: "A/B/C"
 # Isochrone graph for R01
 - rev: "1444db96cbd8cd791abe83527becee73d3c64e86"
   graph:
       entry:
         id: "b3cf11b22c9f93c3c494cf90ab072f394155072d"
         name: ""
       maxdate: 1000000010.0
       path: ""
       children:
         - entry:
             id: "baca735bf8b8720131b4bfdb47c51631a9260348"
             name: "A"
           maxdate: 1000000010.0
           path: "A"
           children:
             - entry:
                 id: "4b28979d88ed209a09c272bcc80f69d9b18339c2"
                 name: "B"
               maxdate: 1000000010.0
               path: "A/B"
               children:
                 - entry:
                     id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                     name: "C"
                   maxdate: 1000000010.0
                   path: "A/B/C"
 # Isochrone graph for R02
 - rev: "0d45f1ee524db8f6f0b5a267afac4e733b4b2cee"
   graph:
     entry:
         id: "195601c98c28f04e0d19c218434738006990db72"
         name: ""
     maxdate: 1000000020.0
     path: ""
     children:
       - entry:
           id: "d591b308488541aabffd854eae85a9bf83a9d9f5"
           name: "A"
         maxdate: 1000000020.0
         path: "A"
         children:
           - entry:
               id: "0e540a8ebea2f5de3e62b92e2139902cf6f46e92"
               name: "B"
             maxdate: 1000000020.0
             path: "A/B"
             children:
               - entry:
                   id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                   name: "C"
                 maxdate: 1000000010.0
-                known: True
                 path: "A/B/C"
 # Isochrone graph for R03
 - rev: "540bd6155a3c50cc47b2e6f43aeaace67a696d1d"
   graph:
     entry:
       id: "cea28838ec1fb757e44b724fe1365d64c6a94e24"
       name: ""
     maxdate: 1000000010.0
-    known: True
     path: ""
     children:
       - entry:
           id: "48007c961cc734d1f63886d0413a6dc605e3e2ea"
           name: "A"
         maxdate: 1000000010.0
-        known: True
         path: "A"
         children:
           - entry:
               id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
               name: "C"
             dbdate: 1000000010.0
             maxdate: 1000000010.0
-            known: True
             path: "A/C"
 # Isochrone graph for R04
 - rev: "17ed10db0612c9b46ba340943cb6b48b25431419"
   graph:
     entry:
       id: "195601c98c28f04e0d19c218434738006990db72"
       name: ""
     maxdate: 1000000020.0
-    known: True
     path: ""
     children:
       - entry:
           id: "d591b308488541aabffd854eae85a9bf83a9d9f5"
           name: "A"
         maxdate: 1000000020.0
-        known: True
         path: "A"
         children:
           - entry:
               id: "0e540a8ebea2f5de3e62b92e2139902cf6f46e92"
               name: "B"
             maxdate: 1000000020.0
-            known: True
             path: "A/B"
             children:
               - entry:
                   id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                   name: "C"
                 dbdate: 1000000010.0
                 maxdate: 1000000010.0
-                known: True
                 path: "A/B/C"
 # Isochrone graph for R05
 - rev: "c8bef45193355db33d64f375b4a4e4f23ac2a4f6"
   graph:
     entry:
       id: "fa63f03d67d1a15563afe9f8ba97832dfb20f42a"
       name: ""
     maxdate: 1000000050.0
     path: ""
     children:
       - entry:
           id: "12f1bc8ca9678ecc055bc65efd7fb4dd1f13457e"
           name: "D"
         maxdate: 1000000050.0
         path: "D"
 # Isochrone graph for R06
 - rev: "f5c16cb16dc29d9e5b25bd3d4d1e252ac7d5493c"
   graph:
     entry:
       id: "c86d2f588234098642ef6f33ca662a6a9de865bc"
       name: ""
     maxdate: 1000000050.0
-    known: True
     path: ""
     children:
       - entry:
           id: "8a3993f4efa9385ce993775cab5ec4dc2c78d7f6"
           name: "D"
         maxdate: 1000000050.0
-        known: True
         path: "D"
         children:
           - entry:
               id: "fa63f03d67d1a15563afe9f8ba97832dfb20f42a"
               name: "E"
             maxdate: 1000000050.0
-            known: True
             path: "D/E"
             children:
             - entry:
                 id: "12f1bc8ca9678ecc055bc65efd7fb4dd1f13457e"
                 name: "D"
               maxdate: 1000000050.0
-              known: True
               path: "D/E/D"
 # Isochrone graph for R07
 - rev: "91ed6a03c80b61e0d63d328f7a4325230e7a0237"
   graph:
     entry:
       id: "641baf6738fa5ebb3c5eb39af45f62ff52f8cc62"
       name: ""
     maxdate: 1000000050.0
-    known: True
     path: ""
     children:
       - entry:
           id: "b0ae56ed5ca7daa34fd7a91a28db443ab3c389a0"
           name: "F"
         maxdate: 1000000050.0
-        known: True
         path: "F"
         children:
           - entry:
               id: "fa63f03d67d1a15563afe9f8ba97832dfb20f42a"
               name: "E"
             maxdate: 1000000050.0
-            known: True
             path: "F/E"
             children:
               - entry:
                   id: "12f1bc8ca9678ecc055bc65efd7fb4dd1f13457e"
                   name: "D"
                 dbdate: 1000000050.0
                 maxdate: 1000000050.0
-                known: True
                 path: "F/E/D"
 # Isochrone graph for R08
 - rev: "a97e5c8a626510eefaa637091924cf800b1e8b06"
   graph:
     entry:
       id: "79e219827e12f40e7146cc6834ee04b617a8073a"
       name: ""
     maxdate: 1000000050.0
-    known: True
     path: ""
     children:
       - entry:
           id: "9a7b5762e20b11735b93a635cda451c75bd31270"
           name: "F"
         maxdate: 1000000050.0
-        known: True
         path: "F"
         children:
           - entry:
               id: "81b84d8fd8ceebd47f51896d19ce1aa286629225"
               name: "E"
             maxdate: 1000000050.0
-            known: True
             path: "F/E"
             children:
               - entry:
                   id: "cb211f2d9dfee6c3968837a07960afd6ab09506c"
                   name: "D"
                 maxdate: 1000000050.0
-                known: True
                 path: "F/E/D"
 # Isochrone graph for R09
 - rev: "3c5ad6be812b182ee2a01e84884b8ab7d384a4a0"
   graph:
     entry:
       id: "53a71b331248f2144f4f012fd7e05f86b8ee62a0"
       name: ""
     maxdate: 1000000090.0
     path: ""
     children:
       - entry:
           id: "16cb311fc491b0b6dfade153191ee1c09d2152cf"
           name: "F"
         maxdate: 1000000090.0
         path: "F"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "E"
             maxdate: 1000000090.0
             path: "F/E"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 maxdate: 1000000090.0
                 path: "F/E/D"
 # Isochrone graph for R10
 - rev: "b7c52e28d441ca0cb736fdbe49e39eae3847ad0f"
   graph:
     entry:
       id: "8c61bb233c89936b310d8b269a35c24bff432227"
       name: ""
     maxdate: 1000000100.0
     path: ""
     children:
       - entry:
           id: "db2b00211f77c6c7f1f742020e483b506b82b5d6"
           name: "F"
         maxdate: 1000000100.0
         path: "F"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "E"
             maxdate: 1000000090.0
-            known: True
             path: "F/E"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 maxdate: 1000000090.0
-                known: True
                 path: "F/E/D"
 # Isochrone graph for R11
 - rev: "f4b2d6d273a6f0d9f2b1299c668b7b7ea095a6a2"
   graph:
     entry:
       id: "b29a1c3fee0057016af424c41d58a8811b8c3a41"
       name: ""
     maxdate: 1000000110.0
     path: ""
     children:
       - entry:
           id: "74fb9789d162f02deabbdfbc3c8daa97f31559a1"
           name: "G"
         maxdate: 1000000110.0
         path: "G"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "E"
             maxdate: 1000000090.0
-            known: True
             path: "G/E"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 dbdate: 1000000090.0
                 maxdate: 1000000090.0
-                known: True
                 path: "G/E/D"
 # Isochrone graph for R12
 - rev: "99bd98e1803343ecfabe4b05d0218475c2b1bf74"
   graph:
     entry:
       id: "6b2d11dd7bc6c7d7dcf59afed80f57413d929cf5"
       name: ""
     maxdate: 1000000120.0
     path: ""
     children:
       - entry:
           id: "5aa1d185e7e32bb53a16ba0db1b06d3a6243b36f"
           name: "G"
         maxdate: 1000000120.0
         path: "G"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "H"
             maxdate: 1000000090.0
-            known: True
             path: "G/H"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 dbdate: 1000000090.0
                 maxdate: 1000000090.0
-                known: True
                 path: "G/H/D"
 # Isochrone graph for R13
 - rev: "10287882c7ed1b7c96f43da269e6a868b98291ff"
   graph:
     entry:
       id: "148f08e057416af1e471abb3dcd594d27233085d"
       name: ""
     maxdate: 1000000130.0
     path: ""
     children:
       - entry:
           id: "8084b999790aab88e5119915ea1083e747a3f42f"
           name: "G"
         maxdate: 1000000130.0
         path: "G"
         children:
           - entry:
               id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
               name: "D"
             dbdate: 1000000090.0
             maxdate: 1000000090.0
-            known: True
             path: "G/D"
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "I"
             maxdate: 1000000090.0
-            known: True
             path: "G/I"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 dbdate: 1000000090.0
                 maxdate: 1000000090.0
-                known: True
                 path: "G/I/D"
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "H"
             maxdate: 1000000090.0
-            known: True
             path: "G/H"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 dbdate: 1000000090.0
                 maxdate: 1000000090.0
-                known: True
                 path: "G/H/D"
diff --git a/swh/provenance/tests/data/graphs_cmdbts2_lower_2.yaml b/swh/provenance/tests/data/graphs_cmdbts2_lower_2.yaml
index b05f986..b370e6f 100644
--- a/swh/provenance/tests/data/graphs_cmdbts2_lower_2.yaml
+++ b/swh/provenance/tests/data/graphs_cmdbts2_lower_2.yaml
@@ -1,401 +1,370 @@
 # Isochrone graph for R00
 - rev: "c0d8929936631ecbcf9147be6b8aa13b13b014e4"
   graph:
     entry:
       id: "a4cb5e6b2831f7e8eef0e6e08e43d642c97303a1"
       name: ""
     maxdate: 1000000000.0
     path: ""
     children:
       - entry:
           id: "1c8d9fd9afa7e5a2cf52a3db6f05dc5c3a1ca86b"
           name: "A"
         maxdate: 1000000000.0
         path: "A"
         children:
           - entry:
               id: "36876d475197b5ad86ad592e8e28818171455f16"
               name: "B"
             maxdate: 1000000000.0
             path: "A/B"
             children:
               - entry:
                   id: "98f7a4a23d8df1fb1a5055facae2aff9b2d0a8b3"
                   name: "C"
                 maxdate: 1000000000.0
                 path: "A/B/C"
 # Isochrone graph for R01
 - rev: "1444db96cbd8cd791abe83527becee73d3c64e86"
   graph:
     entry:
       id: "b3cf11b22c9f93c3c494cf90ab072f394155072d"
       name: ""
     maxdate: 1000000010.0
     path: ""
     children:
       - entry:
           id: "baca735bf8b8720131b4bfdb47c51631a9260348"
           name: "A"
         maxdate: 1000000010.0
         path: "A"
         children:
           - entry:
               id: "4b28979d88ed209a09c272bcc80f69d9b18339c2"
               name: "B"
             maxdate: 1000000010.0
             path: "A/B"
             children:
               - entry:
                   id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                   name: "C"
                 maxdate: 1000000010.0
                 path: "A/B/C"
 # Isochrone graph for R02
 - rev: "0d45f1ee524db8f6f0b5a267afac4e733b4b2cee"
   graph:
     entry:
       id: "195601c98c28f04e0d19c218434738006990db72"
       name: ""
     maxdate: 1000000020.0
     path: ""
     children:
       - entry:
           id: "d591b308488541aabffd854eae85a9bf83a9d9f5"
           name: "A"
         maxdate: 1000000020.0
         path: "A"
         children:
           - entry:
               id: "0e540a8ebea2f5de3e62b92e2139902cf6f46e92"
               name: "B"
             maxdate: 1000000020.0
             path: "A/B"
             children:
               - entry:
                   id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                   name: "C"
                 maxdate: 1000000010.0
-                known: True
                 path: "A/B/C"
 # Isochrone graph for R03
 - rev: "540bd6155a3c50cc47b2e6f43aeaace67a696d1d"
   graph:
     entry:
       id: "cea28838ec1fb757e44b724fe1365d64c6a94e24"
       name: ""
     maxdate: 1000000010.0
-    known: True
     path: ""
     children:
       - entry:
           id: "48007c961cc734d1f63886d0413a6dc605e3e2ea"
           name: "A"
         maxdate: 1000000010.0
-        known: True
         path: "A"
         children:
           - entry:
               id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
               name: "C"
             dbdate: 1000000010.0
             maxdate: 1000000010.0
-            known: True
             path: "A/C"
 # Isochrone graph for R04
 - rev: "17ed10db0612c9b46ba340943cb6b48b25431419"
   graph:
     entry:
       id: "195601c98c28f04e0d19c218434738006990db72"
       name: ""
     maxdate: 1000000020.0
-    known: True
     path: ""
     children:
       - entry:
           id: "d591b308488541aabffd854eae85a9bf83a9d9f5"
           name: "A"
         maxdate: 1000000020.0
-        known: True
         path: "A"
         children:
           - entry:
               id: "0e540a8ebea2f5de3e62b92e2139902cf6f46e92"
               name: "B"
             maxdate: 1000000020.0
-            known: True
             path: "A/B"
             children:
               - entry:
                   id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                   name: "C"
                 dbdate: 1000000010.0
                 maxdate: 1000000010.0
-                known: True
                 path: "A/B/C"
 # Isochrone graph for R05
 - rev: "c8bef45193355db33d64f375b4a4e4f23ac2a4f6"
   graph:
     entry:
       id: "fa63f03d67d1a15563afe9f8ba97832dfb20f42a"
       name: ""
     maxdate: 1000000050.0
     path: ""
     children:
       - entry:
           id: "12f1bc8ca9678ecc055bc65efd7fb4dd1f13457e"
           name: "D"
         maxdate: 1000000050.0
         path: "D"
 # Isochrone graph for R06
 - rev: "f5c16cb16dc29d9e5b25bd3d4d1e252ac7d5493c"
   graph:
     entry:
       id: "c86d2f588234098642ef6f33ca662a6a9de865bc"
       name: ""
     maxdate: 1000000050.0
-    known: True
     path: ""
     children:
       - entry:
           id: "8a3993f4efa9385ce993775cab5ec4dc2c78d7f6"
           name: "D"
         maxdate: 1000000050.0
-        known: True
         path: "D"
         children:
           - entry:
               id: "fa63f03d67d1a15563afe9f8ba97832dfb20f42a"
               name: "E"
             maxdate: 1000000050.0
-            known: True
             path: "D/E"
             children:
               - entry:
                   id: "12f1bc8ca9678ecc055bc65efd7fb4dd1f13457e"
                   name: "D"
                 maxdate: 1000000050.0
-                known: True
                 path: "D/E/D"
 # Isochrone graph for R07
 - rev: "91ed6a03c80b61e0d63d328f7a4325230e7a0237"
   graph:
     entry:
       id: "641baf6738fa5ebb3c5eb39af45f62ff52f8cc62"
       name: ""
     maxdate: 1000000050.0
-    known: True
     path: ""
     children:
       - entry:
           id: "b0ae56ed5ca7daa34fd7a91a28db443ab3c389a0"
           name: "F"
         maxdate: 1000000050.0
-        known: True
         path: "F"
         children:
           - entry:
               id: "fa63f03d67d1a15563afe9f8ba97832dfb20f42a"
               name: "E"
             maxdate: 1000000050.0
-            known: True
             path: "F/E"
             children:
               - entry:
                   id: "12f1bc8ca9678ecc055bc65efd7fb4dd1f13457e"
                   name: "D"
                 dbdate: 1000000050.0
                 maxdate: 1000000050.0
-                known: True
                 path: "F/E/D"
 # Isochrone graph for R08
 - rev: "a97e5c8a626510eefaa637091924cf800b1e8b06"
   graph:
     entry:
       id: "79e219827e12f40e7146cc6834ee04b617a8073a"
       name: ""
     maxdate: 1000000050.0
-    known: True
     path: ""
     children:
       - entry:
           id: "9a7b5762e20b11735b93a635cda451c75bd31270"
           name: "F"
         maxdate: 1000000050.0
-        known: True
         path: "F"
         children:
           - entry:
               id: "81b84d8fd8ceebd47f51896d19ce1aa286629225"
               name: "E"
             maxdate: 1000000050.0
-            known: True
             path: "F/E"
             children:
               - entry:
                   id: "cb211f2d9dfee6c3968837a07960afd6ab09506c"
                   name: "D"
                 maxdate: 1000000050.0
-                known: True
                 path: "F/E/D"
 # Isochrone graph for R09
 - rev: "3c5ad6be812b182ee2a01e84884b8ab7d384a4a0"
   graph:
     entry:
       id: "53a71b331248f2144f4f012fd7e05f86b8ee62a0"
       name: ""
     maxdate: 1000000090.0
     path: ""
     children:
       - entry:
           id: "16cb311fc491b0b6dfade153191ee1c09d2152cf"
           name: "F"
         maxdate: 1000000090.0
         path: "F"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "E"
             maxdate: 1000000090.0
             path: "F/E"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 maxdate: 1000000090.0
                 path: "F/E/D"
 # Isochrone graph for R10
 - rev: "b7c52e28d441ca0cb736fdbe49e39eae3847ad0f"
   graph:
     entry:
       id: "8c61bb233c89936b310d8b269a35c24bff432227"
       name: ""
     maxdate: 1000000100.0
     path: ""
     children:
       - entry:
           id: "db2b00211f77c6c7f1f742020e483b506b82b5d6"
           name: "F"
         maxdate: 1000000100.0
         path: "F"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "E"
             maxdate: 1000000090.0
-            known: True
             path: "F/E"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 maxdate: 1000000090.0
-                known: True
                 path: "F/E/D"
 # Isochrone graph for R11
 - rev: "f4b2d6d273a6f0d9f2b1299c668b7b7ea095a6a2"
   graph:
     entry:
       id: "b29a1c3fee0057016af424c41d58a8811b8c3a41"
       name: ""
     maxdate: 1000000110.0
     path: ""
     children:
       - entry:
           id: "74fb9789d162f02deabbdfbc3c8daa97f31559a1"
           name: "G"
         maxdate: 1000000110.0
         path: "G"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "E"
             maxdate: 1000000090.0
-            known: True
             path: "G/E"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 dbdate: 1000000090.0
                 maxdate: 1000000090.0
-                known: True
                 path: "G/E/D"
 # Isochrone graph for R12
 - rev: "99bd98e1803343ecfabe4b05d0218475c2b1bf74"
   graph:
     entry:
       id: "6b2d11dd7bc6c7d7dcf59afed80f57413d929cf5"
       name: ""
     maxdate: 1000000120.0
     path: ""
     children:
       - entry:
           id: "5aa1d185e7e32bb53a16ba0db1b06d3a6243b36f"
           name: "G"
         maxdate: 1000000120.0
         path: "G"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "H"
             maxdate: 1000000090.0
-            known: True
             path: "G/H"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 dbdate: 1000000090.0
                 maxdate: 1000000090.0
-                known: True
                 path: "G/H/D"
 # Isochrone graph for R13
 - rev: "10287882c7ed1b7c96f43da269e6a868b98291ff"
   graph:
     entry:
       id: "148f08e057416af1e471abb3dcd594d27233085d"
       name: ""
     maxdate: 1000000130.0
     path: ""
     children:
       - entry:
           id: "8084b999790aab88e5119915ea1083e747a3f42f"
           name: "G"
         maxdate: 1000000130.0
         path: "G"
         children:
           - entry:
               id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
               name: "D"
             dbdate: 1000000090.0
             maxdate: 1000000090.0
-            known: True
             path: "G/D"
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "I"
             maxdate: 1000000090.0
-            known: True
             path: "G/I"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 dbdate: 1000000090.0
                 maxdate: 1000000090.0
-                known: True
                 path: "G/I/D"
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "H"
             maxdate: 1000000090.0
-            known: True
             path: "G/H"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 dbdate: 1000000090.0
                 maxdate: 1000000090.0
-                known: True
                 path: "G/H/D"
diff --git a/swh/provenance/tests/data/graphs_cmdbts2_upper_1.yaml b/swh/provenance/tests/data/graphs_cmdbts2_upper_1.yaml
index 45e3a2e..3639820 100644
--- a/swh/provenance/tests/data/graphs_cmdbts2_upper_1.yaml
+++ b/swh/provenance/tests/data/graphs_cmdbts2_upper_1.yaml
@@ -1,371 +1,344 @@
 # Isochrone graph for R00
 - rev: "c0d8929936631ecbcf9147be6b8aa13b13b014e4"
   graph:
     entry:
       id: "a4cb5e6b2831f7e8eef0e6e08e43d642c97303a1"
       name: ""
     maxdate: 1000000000.0
     path: ""
     children:
       - entry:
           id: "1c8d9fd9afa7e5a2cf52a3db6f05dc5c3a1ca86b"
           name: "A"
         maxdate: 1000000000.0
         path: "A"
         children:
           - entry:
               id: "36876d475197b5ad86ad592e8e28818171455f16"
               name: "B"
             maxdate: 1000000000.0
             path: "A/B"
             children:
               - entry:
                   id: "98f7a4a23d8df1fb1a5055facae2aff9b2d0a8b3"
                   name: "C"
                 maxdate: 1000000000.0
                 path: "A/B/C"
 # Isochrone graph for R01
 - rev: "1444db96cbd8cd791abe83527becee73d3c64e86"
   graph:
     entry:
       id: "b3cf11b22c9f93c3c494cf90ab072f394155072d"
       name: ""
     maxdate: 1000000010.0
     path: ""
     children:
       - entry:
           id: "baca735bf8b8720131b4bfdb47c51631a9260348"
           name: "A"
         maxdate: 1000000010.0
         path: "A"
         children:
           - entry:
               id: "4b28979d88ed209a09c272bcc80f69d9b18339c2"
               name: "B"
             maxdate: 1000000010.0
             path: "A/B"
             children:
               - entry:
                   id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                   name: "C"
                 maxdate: 1000000010.0
                 path: "A/B/C"
 # Isochrone graph for R02
 - rev: "0d45f1ee524db8f6f0b5a267afac4e733b4b2cee"
   graph:
     entry:
       id: "195601c98c28f04e0d19c218434738006990db72"
       name: ""
     maxdate: 1000000020.0
     path: ""
     children:
       - entry:
           id: "d591b308488541aabffd854eae85a9bf83a9d9f5"
           name: "A"
         maxdate: 1000000020.0
         path: "A"
         children:
           - entry:
               id: "0e540a8ebea2f5de3e62b92e2139902cf6f46e92"
               name: "B"
             maxdate: 1000000020.0
             path: "A/B"
             children:
               - entry:
                   id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                   name: "C"
                 maxdate: 1000000010.0
-                known: True
                 path: "A/B/C"
 # Isochrone graph for R03
 - rev: "540bd6155a3c50cc47b2e6f43aeaace67a696d1d"
   graph:
     entry:
       id: "cea28838ec1fb757e44b724fe1365d64c6a94e24"
       name: ""
     maxdate: 1000000010.0
-    known: True
     path: ""
     children:
       - entry:
           id: "48007c961cc734d1f63886d0413a6dc605e3e2ea"
           name: "A"
         maxdate: 1000000010.0
-        known: True
         path: "A"
         children:
           - entry:
               id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
               name: "C"
             dbdate: 1000000010.0
             maxdate: 1000000010.0
-            known: True
             path: "A/C"
 # Isochrone graph for R04
 - rev: "17ed10db0612c9b46ba340943cb6b48b25431419"
   graph:
     entry:
       id: "195601c98c28f04e0d19c218434738006990db72"
       name: ""
     maxdate: 1000000020.0
-    known: True
     path: ""
     children:
       - entry:
           id: "d591b308488541aabffd854eae85a9bf83a9d9f5"
           name: "A"
         maxdate: 1000000020.0
-        known: True
         path: "A"
         children:
           - entry:
               id: "0e540a8ebea2f5de3e62b92e2139902cf6f46e92"
               name: "B"
             maxdate: 1000000020.0
-            known: True
             path: "A/B"
             children:
               - entry:
                   id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                   name: "C"
                 dbdate: 1000000010.0
                 maxdate: 1000000010.0
-                known: True
                 path: "A/B/C"
 # Isochrone graph for R05
 - rev: "c8bef45193355db33d64f375b4a4e4f23ac2a4f6"
   graph:
     entry:
       id: "fa63f03d67d1a15563afe9f8ba97832dfb20f42a"
       name: ""
     maxdate: 1000000050.0
     path: ""
     children:
       - entry:
           id: "12f1bc8ca9678ecc055bc65efd7fb4dd1f13457e"
           name: "D"
         maxdate: 1000000050.0
         path: "D"
 # Isochrone graph for R06
 - rev: "f5c16cb16dc29d9e5b25bd3d4d1e252ac7d5493c"
   graph:
     entry:
       id: "c86d2f588234098642ef6f33ca662a6a9de865bc"
       name: ""
     maxdate: 1000000050.0
-    known: True
     path: ""
     children:
       - entry:
           id: "8a3993f4efa9385ce993775cab5ec4dc2c78d7f6"
           name: "D"
         maxdate: 1000000050.0
-        known: True
         path: "D"
         children:
           - entry:
               id: "fa63f03d67d1a15563afe9f8ba97832dfb20f42a"
               name: "E"
             maxdate: 1000000050.0
-            known: True
             path: "D/E"
             children:
               - entry:
                   id: "12f1bc8ca9678ecc055bc65efd7fb4dd1f13457e"
                   name: "D"
                 maxdate: 1000000050.0
-                known: True
                 path: "D/E/D"
 # Isochrone graph for R07
 - rev: "91ed6a03c80b61e0d63d328f7a4325230e7a0237"
   graph:
     entry:
       id: "641baf6738fa5ebb3c5eb39af45f62ff52f8cc62"
       name: ""
     maxdate: 1000000050.0
-    known: True
     path: ""
     children:
       - entry:
           id: "b0ae56ed5ca7daa34fd7a91a28db443ab3c389a0"
           name: "F"
         maxdate: 1000000050.0
-        known: True
         path: "F"
         children:
           - entry:
               id: "fa63f03d67d1a15563afe9f8ba97832dfb20f42a"
               name: "E"
             maxdate: 1000000050.0
-            known: True
             path: "F/E"
             children:
               - entry:
                   id: "12f1bc8ca9678ecc055bc65efd7fb4dd1f13457e"
                   name: "D"
                 maxdate: 1000000050.0
-                known: True
                 path: "F/E/D"
 # Isochrone graph for R08
 - rev: "a97e5c8a626510eefaa637091924cf800b1e8b06"
   graph:
     entry:
       id: "79e219827e12f40e7146cc6834ee04b617a8073a"
       name: ""
     maxdate: 1000000050.0
-    known: True
     path: ""
     children:
       - entry:
           id: "9a7b5762e20b11735b93a635cda451c75bd31270"
           name: "F"
         maxdate: 1000000050.0
-        known: True
         path: "F"
         children:
           - entry:
               id: "81b84d8fd8ceebd47f51896d19ce1aa286629225"
               name: "E"
             maxdate: 1000000050.0
-            known: True
             path: "F/E"
             children:
               - entry:
                   id: "cb211f2d9dfee6c3968837a07960afd6ab09506c"
                   name: "D"
                 maxdate: 1000000050.0
-                known: True
                 path: "F/E/D"
 # Isochrone graph for R09
 - rev: "3c5ad6be812b182ee2a01e84884b8ab7d384a4a0"
   graph:
     entry:
       id: "53a71b331248f2144f4f012fd7e05f86b8ee62a0"
       name: ""
     maxdate: 1000000090.0
     path: ""
     children:
       - entry:
           id: "16cb311fc491b0b6dfade153191ee1c09d2152cf"
           name: "F"
         maxdate: 1000000090.0
         path: "F"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "E"
             maxdate: 1000000090.0
             path: "F/E"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 maxdate: 1000000090.0
                 path: "F/E/D"
 # Isochrone graph for R10
 - rev: "b7c52e28d441ca0cb736fdbe49e39eae3847ad0f"
   graph:
     entry:
       id: "8c61bb233c89936b310d8b269a35c24bff432227"
       name: ""
     maxdate: 1000000100.0
     path: ""
     children:
       - entry:
           id: "db2b00211f77c6c7f1f742020e483b506b82b5d6"
           name: "F"
         maxdate: 1000000100.0
         path: "F"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "E"
             maxdate: 1000000090.0
-            known: True
             path: "F/E"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 maxdate: 1000000090.0
-                known: True
                 path: "F/E/D"
 # Isochrone graph for R11
 - rev: "f4b2d6d273a6f0d9f2b1299c668b7b7ea095a6a2"
   graph:
     entry:
       id: "b29a1c3fee0057016af424c41d58a8811b8c3a41"
       name: ""
     maxdate: 1000000110.0
     path: ""
     children:
       - entry:
           id: "74fb9789d162f02deabbdfbc3c8daa97f31559a1"
           name: "G"
         maxdate: 1000000110.0
         path: "G"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "E"
             dbdate: 1000000090.0
             maxdate: 1000000090.0
-            known: True
             path: "G/E"
 # Isochrone graph for R12
 - rev: "99bd98e1803343ecfabe4b05d0218475c2b1bf74"
   graph:
     entry:
       id: "6b2d11dd7bc6c7d7dcf59afed80f57413d929cf5"
       name: ""
     maxdate: 1000000120.0
     path: ""
     children:
       - entry:
           id: "5aa1d185e7e32bb53a16ba0db1b06d3a6243b36f"
           name: "G"
         maxdate: 1000000120.0
         path: "G"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "H"
             dbdate: 1000000090.0
             maxdate: 1000000090.0
-            known: True
             path: "G/H"
 # Isochrone graph for R13
 - rev: "10287882c7ed1b7c96f43da269e6a868b98291ff"
   graph:
     entry:
       id: "148f08e057416af1e471abb3dcd594d27233085d"
       name: ""
     maxdate: 1000000130.0
     path: ""
     children:
       - entry:
           id: "8084b999790aab88e5119915ea1083e747a3f42f"
           name: "G"
         maxdate: 1000000130.0
         path: "G"
         children:
           - entry:
               id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
               name: "D"
             maxdate: 1000000090.0
-            known: True
             path: "G/D"
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "I"
             dbdate: 1000000090.0
             maxdate: 1000000090.0
-            known: True
             path: "G/I"
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "H"
             dbdate: 1000000090.0
             maxdate: 1000000090.0
-            known: True
             path: "G/H"
diff --git a/swh/provenance/tests/data/graphs_cmdbts2_upper_2.yaml b/swh/provenance/tests/data/graphs_cmdbts2_upper_2.yaml
index cee448f..8ed1c0f 100644
--- a/swh/provenance/tests/data/graphs_cmdbts2_upper_2.yaml
+++ b/swh/provenance/tests/data/graphs_cmdbts2_upper_2.yaml
@@ -1,365 +1,339 @@
 # Isochrone graph for R00
 - rev: "c0d8929936631ecbcf9147be6b8aa13b13b014e4"
   graph:
     entry:
       id: "a4cb5e6b2831f7e8eef0e6e08e43d642c97303a1"
       name: ""
     maxdate: 1000000000.0
     path: ""
     children:
       - entry:
           id: "1c8d9fd9afa7e5a2cf52a3db6f05dc5c3a1ca86b"
           name: "A"
         maxdate: 1000000000.0
         path: "A"
         children:
           - entry:
               id: "36876d475197b5ad86ad592e8e28818171455f16"
               name: "B"
             maxdate: 1000000000.0
             path: "A/B"
             children:
               - entry:
                   id: "98f7a4a23d8df1fb1a5055facae2aff9b2d0a8b3"
                   name: "C"
                 maxdate: 1000000000.0
                 path: "A/B/C"
 # Isochrone graph for R01
 - rev: "1444db96cbd8cd791abe83527becee73d3c64e86"
   graph:
     entry:
       id: "b3cf11b22c9f93c3c494cf90ab072f394155072d"
       name: ""
     maxdate: 1000000010.0
     path: ""
     children:
       - entry:
           id: "baca735bf8b8720131b4bfdb47c51631a9260348"
           name: "A"
         maxdate: 1000000010.0
         path: "A"
         children:
           - entry:
               id: "4b28979d88ed209a09c272bcc80f69d9b18339c2"
               name: "B"
             maxdate: 1000000010.0
             path: "A/B"
             children:
               - entry:
                   id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                   name: "C"
                 maxdate: 1000000010.0
                 path: "A/B/C"
 # Isochrone graph for R02
 - rev: "0d45f1ee524db8f6f0b5a267afac4e733b4b2cee"
   graph:
     entry:
       id: "195601c98c28f04e0d19c218434738006990db72"
       name: ""
     maxdate: 1000000020.0
     path: ""
     children:
       - entry:
           id: "d591b308488541aabffd854eae85a9bf83a9d9f5"
           name: "A"
         maxdate: 1000000020.0
         path: "A"
         children:
           - entry:
               id: "0e540a8ebea2f5de3e62b92e2139902cf6f46e92"
               name: "B"
             maxdate: 1000000020.0
             path: "A/B"
             children:
               - entry:
                   id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                   name: "C"
                 maxdate: 1000000010.0
-                known: True
                 path: "A/B/C"
 # Isochrone graph for R03
 - rev: "540bd6155a3c50cc47b2e6f43aeaace67a696d1d"
   graph:
     entry:
       id: "cea28838ec1fb757e44b724fe1365d64c6a94e24"
       name: ""
     maxdate: 1000000010.0
-    known: True
     path: ""
     children:
       - entry:
           id: "48007c961cc734d1f63886d0413a6dc605e3e2ea"
           name: "A"
         maxdate: 1000000010.0
-        known: True
         path: "A"
         children:
           - entry:
               id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
               name: "C"
             dbdate: 1000000010.0
             maxdate: 1000000010.0
-            known: True
             path: "A/C"
 # Isochrone graph for R04
 - rev: "17ed10db0612c9b46ba340943cb6b48b25431419"
   graph:
     entry:
       id: "195601c98c28f04e0d19c218434738006990db72"
       name: ""
     maxdate: 1000000020.0
-    known: True
     path: ""
     children:
       - entry:
           id: "d591b308488541aabffd854eae85a9bf83a9d9f5"
           name: "A"
         maxdate: 1000000020.0
-        known: True
         path: "A"
         children:
           - entry:
               id: "0e540a8ebea2f5de3e62b92e2139902cf6f46e92"
               name: "B"
             maxdate: 1000000020.0
-            known: True
             path: "A/B"
             children:
               - entry:
                   id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                   name: "C"
                 dbdate: 1000000010.0
                 maxdate: 1000000010.0
-                known: True
                 path: "A/B/C"
 # Isochrone graph for R05
 - rev: "c8bef45193355db33d64f375b4a4e4f23ac2a4f6"
   graph:
     entry:
       id: "fa63f03d67d1a15563afe9f8ba97832dfb20f42a"
       name: ""
     maxdate: 1000000050.0
     path: ""
     children:
       - entry:
           id: "12f1bc8ca9678ecc055bc65efd7fb4dd1f13457e"
           name: "D"
         maxdate: 1000000050.0
         path: "D"
 # Isochrone graph for R06
 - rev: "f5c16cb16dc29d9e5b25bd3d4d1e252ac7d5493c"
   graph:
     entry:
       id: "c86d2f588234098642ef6f33ca662a6a9de865bc"
       name: ""
     maxdate: 1000000050.0
-    known: True
     path: ""
     children:
       - entry:
           id: "8a3993f4efa9385ce993775cab5ec4dc2c78d7f6"
           name: "D"
         maxdate: 1000000050.0
-        known: True
         path: "D"
         children:
           - entry:
               id: "fa63f03d67d1a15563afe9f8ba97832dfb20f42a"
               name: "E"
             maxdate: 1000000050.0
-            known: True
             path: "D/E"
             children:
               - entry:
                   id: "12f1bc8ca9678ecc055bc65efd7fb4dd1f13457e"
                   name: "D"
                 maxdate: 1000000050.0
-                known: True
                 path: "D/E/D"
 # Isochrone graph for R07
 - rev: "91ed6a03c80b61e0d63d328f7a4325230e7a0237"
   graph:
     entry:
       id: "641baf6738fa5ebb3c5eb39af45f62ff52f8cc62"
       name: ""
     maxdate: 1000000050.0
-    known: True
     path: ""
     children:
       - entry:
           id: "b0ae56ed5ca7daa34fd7a91a28db443ab3c389a0"
           name: "F"
         maxdate: 1000000050.0
-        known: True
         path: "F"
         children:
           - entry:
               id: "fa63f03d67d1a15563afe9f8ba97832dfb20f42a"
               name: "E"
             dbdate: 1000000050.0
             maxdate: 1000000050.0
-            known: True
             path: "F/E"
 # Isochrone graph for R08
 - rev: "a97e5c8a626510eefaa637091924cf800b1e8b06"
   graph:
     entry:
       id: "79e219827e12f40e7146cc6834ee04b617a8073a"
       name: ""
     maxdate: 1000000050.0
-    known: True
     path: ""
     children:
       - entry:
           id: "9a7b5762e20b11735b93a635cda451c75bd31270"
           name: "F"
         maxdate: 1000000050.0
-        known: True
         path: "F"
         children:
           - entry:
               id: "81b84d8fd8ceebd47f51896d19ce1aa286629225"
               name: "E"
             maxdate: 1000000050.0
-            known: True
             path: "F/E"
             children:
               - entry:
                   id: "cb211f2d9dfee6c3968837a07960afd6ab09506c"
                   name: "D"
                 maxdate: 1000000050.0
-                known: True
                 path: "F/E/D"
 # Isochrone graph for R09
 - rev: "3c5ad6be812b182ee2a01e84884b8ab7d384a4a0"
   graph:
     entry:
       id: "53a71b331248f2144f4f012fd7e05f86b8ee62a0"
       name: ""
     maxdate: 1000000090.0
     path: ""
     children:
       - entry:
           id: "16cb311fc491b0b6dfade153191ee1c09d2152cf"
           name: "F"
         maxdate: 1000000090.0
         path: "F"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "E"
             maxdate: 1000000090.0
             path: "F/E"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 maxdate: 1000000090.0
                 path: "F/E/D"
 # Isochrone graph for R10
 - rev: "b7c52e28d441ca0cb736fdbe49e39eae3847ad0f"
   graph:
     entry:
       id: "8c61bb233c89936b310d8b269a35c24bff432227"
       name: ""
     maxdate: 1000000100.0
     path: ""
     children:
       - entry:
           id: "db2b00211f77c6c7f1f742020e483b506b82b5d6"
           name: "F"
         maxdate: 1000000100.0
         path: "F"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "E"
             maxdate: 1000000090.0
-            known: True
             path: "F/E"
             children:
               - entry:
                   id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
                   name: "D"
                 maxdate: 1000000090.0
-                known: True
                 path: "F/E/D"
 # Isochrone graph for R11
 - rev: "f4b2d6d273a6f0d9f2b1299c668b7b7ea095a6a2"
   graph:
     entry:
       id: "b29a1c3fee0057016af424c41d58a8811b8c3a41"
       name: ""
     maxdate: 1000000110.0
     path: ""
     children:
       - entry:
           id: "74fb9789d162f02deabbdfbc3c8daa97f31559a1"
           name: "G"
         maxdate: 1000000110.0
         path: "G"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "E"
             dbdate: 1000000090.0
             maxdate: 1000000090.0
-            known: True
             path: "G/E"
 # Isochrone graph for R12
 - rev: "99bd98e1803343ecfabe4b05d0218475c2b1bf74"
   graph:
     entry:
       id: "6b2d11dd7bc6c7d7dcf59afed80f57413d929cf5"
       name: ""
     maxdate: 1000000120.0
     path: ""
     children:
       - entry:
           id: "5aa1d185e7e32bb53a16ba0db1b06d3a6243b36f"
           name: "G"
         maxdate: 1000000120.0
         path: "G"
         children:
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "H"
             dbdate: 1000000090.0
             maxdate: 1000000090.0
-            known: True
             path: "G/H"
 # Isochrone graph for R13
 - rev: "10287882c7ed1b7c96f43da269e6a868b98291ff"
   graph:
     entry:
       id: "148f08e057416af1e471abb3dcd594d27233085d"
       name: ""
     maxdate: 1000000130.0
     path: ""
     children:
       - entry:
           id: "8084b999790aab88e5119915ea1083e747a3f42f"
           name: "G"
         maxdate: 1000000130.0
         path: "G"
         children:
           - entry:
               id: "2cb3ae467165716d1d0e7fa85190d753c3b76d78"
               name: "D"
             maxdate: 1000000090.0
-            known: True
             path: "G/D"
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "I"
             dbdate: 1000000090.0
             maxdate: 1000000090.0
-            known: True
             path: "G/I"
           - entry:
               id: "8b4df27934ce48db6f4bdf326b3bce89d4571252"
               name: "H"
             dbdate: 1000000090.0
             maxdate: 1000000090.0
-            known: True
             path: "G/H"
diff --git a/swh/provenance/tests/data/graphs_out-of-order_lower_1.yaml b/swh/provenance/tests/data/graphs_out-of-order_lower_1.yaml
index 147e560..a4aad93 100644
--- a/swh/provenance/tests/data/graphs_out-of-order_lower_1.yaml
+++ b/swh/provenance/tests/data/graphs_out-of-order_lower_1.yaml
@@ -1,185 +1,174 @@
 # Isochrone graph for R00
 - rev: "c0d8929936631ecbcf9147be6b8aa13b13b014e4"
   graph:
     entry:
       id: "a4cb5e6b2831f7e8eef0e6e08e43d642c97303a1"
       name: ""
     maxdate: 1000000000.0
     path: ""
     children:
       - entry:
           id: "1c8d9fd9afa7e5a2cf52a3db6f05dc5c3a1ca86b"
           name: "A"
         maxdate: 1000000000.0
         path: "A"
         children:
           - entry:
               id: "36876d475197b5ad86ad592e8e28818171455f16"
               name: "B"
             maxdate: 1000000000.0
             path: "A/B"
             children:
               - entry:
                   id: "98f7a4a23d8df1fb1a5055facae2aff9b2d0a8b3"
                   name: "C"
                 maxdate: 1000000000.0
                 path: "A/B/C"
 # Isochrone graph for R01
 - rev: "1444db96cbd8cd791abe83527becee73d3c64e86"
   graph:
     entry:
       id: "b3cf11b22c9f93c3c494cf90ab072f394155072d"
       name: ""
     maxdate: 1000000010.0
     path: ""
     children:
       - entry:
           id: "baca735bf8b8720131b4bfdb47c51631a9260348"
           name: "A"
         maxdate: 1000000010.0
         path: "A"
         children:
           - entry:
               id: "4b28979d88ed209a09c272bcc80f69d9b18339c2"
               name: "B"
             maxdate: 1000000010.0
             path: "A/B"
             children:
             - entry:
                 id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                 name: "C"
               maxdate: 1000000010.0
               path: "A/B/C"
 # Isochrone graph for R02
 - rev: "1c533587277731236616cac0d44f3b46c1da0f8a"
   graph:
     entry:
       id: "2afae58027276dad2bdced5a505e8d781a7add5b"
       name: ""
     maxdate: 1000000010.0
-    known: True
     path: ""
     children:
       - entry:
           id: "4b28979d88ed209a09c272bcc80f69d9b18339c2"
           name: "A"
         maxdate: 1000000010.0
-        known: True
         path: "A"
         children:
           - entry:
               id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
               name: "C"
             maxdate: 1000000010.0
-            known: True
             path: "A/C"
 # Isochrone graph for R03
 - rev: "20f4da0f48609d9f7f908ebbcac3b3741a0f25cb"
   graph:
     entry:
       id: "b3cf11b22c9f93c3c494cf90ab072f394155072d"
       name: ""
     maxdate: 1000000010.0
-    known: True
     path: ""
     children:
       - entry:
           id: "baca735bf8b8720131b4bfdb47c51631a9260348"
           name: "A"
         maxdate: 1000000010.0
-        known: True
         path: "A"
         children:
           - entry:
               id: "4b28979d88ed209a09c272bcc80f69d9b18339c2"
               name: "B"
             maxdate: 1000000010.0
-            known: True
             path: "A/B"
             children:
               - entry:
                   id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                   name: "C"
                 dbdate: 1000000010.0
                 maxdate: 1000000010.0
-                known: True
                 path: "A/B/C"
 # Isochrone graph for R04
 - rev: "0d66eadcc15e0d7f6cfd4289329a7749a1309982"
   graph:
     entry:
       id: "2afae58027276dad2bdced5a505e8d781a7add5b"
       name: ""
     maxdate: 1000000010.0
-    known: True
     path: ""
     children:
       - entry:
           id: "4b28979d88ed209a09c272bcc80f69d9b18339c2"
           name: "A"
         maxdate: 1000000010.0
-        known: True
         path: "A"
         children:
           - entry:
               id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
               name: "C"
             dbdate: 1000000010.0
             maxdate: 1000000010.0
-            known: True
             path: "A/C"
 # Isochrone graph for R05
 - rev: "1dfac0491892096948d6a02bf12a2fed4bf75743"
   graph:
     entry:
       id: "b3cf11b22c9f93c3c494cf90ab072f394155072d"
       name: ""
     maxdate: 1000000005.0
     path: ""
     children:
       - entry:
           id: "baca735bf8b8720131b4bfdb47c51631a9260348"
           name: "A"
         maxdate: 1000000005.0
         path: "A"
         children:
           - entry:
               id: "4b28979d88ed209a09c272bcc80f69d9b18339c2"
               name: "B"
             maxdate: 1000000005.0
             path: "A/B"
             children:
             - entry:
                 id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                 name: "C"
               maxdate: 1000000005.0
               invalid: True
               path: "A/B/C"
 # Isochrone graph for R06
 - rev: "53519b5a5e8cf12a4f81f82e489f95c1d04d5314"
   graph:
     entry:
       id: "195601c98c28f04e0d19c218434738006990db72"
       name: ""
     maxdate: 1000000050.0
     path: ""
     children:
       - entry:
           id: "d591b308488541aabffd854eae85a9bf83a9d9f5"
           name: "A"
         maxdate: 1000000050.0
         path: "A"
         children:
           - entry:
               id: "0e540a8ebea2f5de3e62b92e2139902cf6f46e92"
               name: "B"
             maxdate: 1000000050.0
             path: "A/B"
             children:
               - entry:
                   id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                   name: "C"
                 dbdate: 1000000005.0
                 maxdate: 1000000005.0
-                known: True
                 path: "A/B/C"
diff --git a/swh/provenance/tests/test_isochrone_graph.py b/swh/provenance/tests/test_isochrone_graph.py
index 364a564..11d5881 100644
--- a/swh/provenance/tests/test_isochrone_graph.py
+++ b/swh/provenance/tests/test_isochrone_graph.py
@@ -1,114 +1,113 @@
 # Copyright (C) 2021  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 from copy import deepcopy
 from datetime import datetime, timezone
 from typing import Any, Dict
 
 import pytest
 import yaml
 
 from swh.model.hashutil import hash_to_bytes
 from swh.provenance.archive import ArchiveInterface
 from swh.provenance.graph import IsochroneNode, build_isochrone_graph
 from swh.provenance.interface import ProvenanceInterface
 from swh.provenance.model import DirectoryEntry, RevisionEntry
 from swh.provenance.revision import revision_add
 from swh.provenance.tests.conftest import (
     fill_storage,
     get_datafile,
     load_repo_data,
     ts2dt,
 )
 
 
 def isochrone_graph_from_dict(d: Dict[str, Any], depth: int = 0) -> IsochroneNode:
     """Takes a dictionary representing a tree of IsochroneNode objects, and
     recursively builds the corresponding graph."""
     d = deepcopy(d)
 
     d["entry"]["id"] = hash_to_bytes(d["entry"]["id"])
     d["entry"]["name"] = bytes(d["entry"]["name"], encoding="utf-8")
 
     dbdate = d.get("dbdate", None)
     if dbdate is not None:
         dbdate = datetime.fromtimestamp(d["dbdate"], timezone.utc)
 
     children = d.get("children", [])
 
     node = IsochroneNode(
         entry=DirectoryEntry(**d["entry"]),
         dbdate=dbdate,
         depth=depth,
     )
     node.maxdate = datetime.fromtimestamp(d["maxdate"], timezone.utc)
-    node.known = d.get("known", False)
     node.invalid = d.get("invalid", False)
     node.path = bytes(d["path"], encoding="utf-8")
     node.children = set(
         isochrone_graph_from_dict(child, depth=depth + 1) for child in children
     )
     return node
 
 
 @pytest.mark.parametrize(
     "repo, lower, mindepth",
     (
         ("cmdbts2", True, 1),
         ("cmdbts2", False, 1),
         ("cmdbts2", True, 2),
         ("cmdbts2", False, 2),
         ("out-of-order", True, 1),
     ),
 )
 @pytest.mark.parametrize("batch", (True, False))
 def test_isochrone_graph(
     provenance: ProvenanceInterface,
     archive: ArchiveInterface,
     repo: str,
     lower: bool,
     mindepth: int,
     batch: bool,
 ) -> None:
     # read data/README.md for more details on how these datasets are generated
     data = load_repo_data(repo)
     fill_storage(archive.storage, data)
 
     revisions = {rev["id"]: rev for rev in data["revision"]}
     filename = f"graphs_{repo}_{'lower' if lower else 'upper'}_{mindepth}.yaml"
 
     with open(get_datafile(filename)) as file:
         for expected in yaml.full_load(file):
             print("# Processing revision", expected["rev"])
             revision = revisions[hash_to_bytes(expected["rev"])]
             entry = RevisionEntry(
                 id=revision["id"],
                 date=ts2dt(revision["date"]),
                 root=revision["directory"],
             )
             expected_graph = isochrone_graph_from_dict(expected["graph"])
             print("Expected graph:", expected_graph)
 
             # Create graph for current revision and check it has the expected structure.
             assert entry.root is not None
             computed_graph = build_isochrone_graph(
                 provenance,
                 archive,
                 entry,
                 DirectoryEntry(entry.root),
             )
             print("Computed graph:", computed_graph)
             assert computed_graph == expected_graph
 
             # Add current revision so that provenance info is kept up to date for the
             # following ones.
             revision_add(
                 provenance,
                 archive,
                 [entry],
                 lower=lower,
                 mindepth=mindepth,
                 commit=not batch,
             )