diff --git a/swh/dataset/exporters/orc.py b/swh/dataset/exporters/orc.py
--- a/swh/dataset/exporters/orc.py
+++ b/swh/dataset/exporters/orc.py
@@ -9,86 +9,28 @@
 from pyorc import BigInt, Binary, Int, SmallInt, String, Struct, Timestamp, Writer
 
 from swh.dataset.exporter import ExporterDispatch
+from swh.dataset.relational import TABLES
 from swh.dataset.utils import remove_pull_requests
 from swh.model.hashutil import hash_to_hex
 
-# fmt: off
+ORC_TYPE_MAP = {
+    "string": String,
+    "smallint": SmallInt,
+    "int": Int,
+    "bigint": BigInt,
+    "timestamp": Timestamp,
+    "binary": Binary,
+}
+
 EXPORT_SCHEMA = {
-    'origin': Struct(
-        url=String()
-    ),
-    'origin_visit': Struct(
-        origin=String(),
-        visit=BigInt(),
-        date=Timestamp(),
-        type=String(),
-    ),
-    'origin_visit_status': Struct(
-        origin=String(),
-        visit=BigInt(),
-        date=Timestamp(),
-        status=String(),
-        snapshot=String(),
-    ),
-    'snapshot': Struct(
-        id=String(),
-    ),
-    'snapshot_branch': Struct(
-        snapshot_id=String(),
-        name=Binary(),
-        target=String(),
-        target_type=String(),
-    ),
-    'release': Struct(
-        id=String(),
-        name=Binary(),
-        message=Binary(),
-        target=String(),
-        target_type=String(),
-        author=Binary(),
-        date=Timestamp(),
-        date_offset=SmallInt(),
-    ),
-    'revision': Struct(
-        id=String(),
-        message=Binary(),
-        author=Binary(),
-        date=Timestamp(),
-        date_offset=SmallInt(),
-        committer=Binary(),
-        committer_date=Timestamp(),
-        committer_offset=SmallInt(),
-        directory=String(),
-    ),
-    'directory': Struct(
-        id=String(),
-    ),
-    'directory_entry': Struct(
-        directory_id=String(),
-        name=Binary(),
-        type=String(),
-        target=String(),
-        perms=Int(),
-    ),
-    'content': Struct(
-        sha1=String(),
-        sha1_git=String(),
-        sha256=String(),
-        blake2s256=String(),
-        length=BigInt(),
-        status=String(),
-    ),
-    'skipped_content': Struct(
-        sha1=String(),
-        sha1_git=String(),
-        sha256=String(),
-        blake2s256=String(),
-        length=BigInt(),
-        status=String(),
-        reason=String(),
-    ),
+    table_name: Struct(
+        **{
+            column_name: ORC_TYPE_MAP[column_type]()
+            for column_name, column_type in columns
+        }
+    )
+    for table_name, columns in TABLES.items()
 }
-# fmt: on
 
 
 def hash_to_hex_or_none(hash):
diff --git a/swh/dataset/relational.py b/swh/dataset/relational.py
new file mode 100644
--- /dev/null
+++ b/swh/dataset/relational.py
@@ -0,0 +1,77 @@
+# fmt: off
+TABLES = {
+    "origin": [
+        ("url", "string"),
+    ],
+    "origin_visit": [
+        ("origin", "string"),
+        ("visit", "bigint"),
+        ("date", "timestamp"),
+        ("type", "string"),
+    ],
+    "origin_visit_status": [
+        ("origin", "string"),
+        ("visit", "bigint"),
+        ("date", "timestamp"),
+        ("status", "string"),
+        ("snapshot", "string"),
+    ],
+    "snapshot": [
+        ("id", "string"),
+    ],
+    "snapshot_branch": [
+        ("snapshot_id", "string"),
+        ("name", "binary"),
+        ("target", "string"),
+        ("target_type", "string"),
+    ],
+    "release": [
+        ("id", "string"),
+        ("name", "binary"),
+        ("message", "binary"),
+        ("target", "string"),
+        ("target_type", "string"),
+        ("author", "binary"),
+        ("date", "timestamp"),
+        ("date_offset", "smallint"),
+    ],
+    "revision": [
+        ("id", "string"),
+        ("message", "binary"),
+        ("author", "binary"),
+        ("date", "timestamp"),
+        ("date_offset", "smallint"),
+        ("committer", "binary"),
+        ("committer_date", "timestamp"),
+        ("committer_offset", "smallint"),
+        ("directory", "string"),
+    ],
+    "directory": [
+        ("id", "string"),
+    ],
+    "directory_entry": [
+        ("directory_id", "string"),
+        ("name", "binary"),
+        ("type", "string"),
+        ("target", "string"),
+        ("perms", "int"),
+    ],
+    "content": [
+        ("sha1", "string"),
+        ("sha1_git", "string"),
+        ("sha256", "string"),
+        ("blake2s256", "string"),
+        ("length", "bigint"),
+        ("status", "string"),
+    ],
+    "skipped_content": [
+        ("sha1", "string"),
+        ("sha1_git", "string"),
+        ("sha256", "string"),
+        ("blake2s256", "string"),
+        ("length", "bigint"),
+        ("status", "string"),
+        ("reason", "string"),
+    ],
+}
+# fmt: on