diff --git a/sql/swh-graph/README.md b/sql/swh-graph/README.md
new file mode 100644
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+++ b/sql/swh-graph/README.md
@@ -0,0 +1,6 @@
+SQL queries to compute the size of the **Software Heritage graph**, which has
+as nodes commits/trees/blobs, and as edges the relations among them.
+
+The main file is swh-graph.txt, in org-mode, which generates swh-graph.sql
+using org-babel-tangle (C-c C-v t). swh-graph.out are the last results obtained
+running the query.
diff --git a/sql/swh-graph/swh-graph.out b/sql/swh-graph/swh-graph.out
new file mode 100644
index 0000000..2239be8
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+++ b/sql/swh-graph/swh-graph.out
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+Timing is on.
+create temporary view counts as
+    select relname as tbl, reltuples::bigint as tuples
+    from pg_class
+    where relnamespace = 'public'::regnamespace
+    and relkind = 'r'  
+    order by relname;
+CREATE VIEW
+Time: 160,458 ms
+create temporary table nodes (
+    description  text,
+    tuples       bigint not null
+);
+CREATE TABLE
+Time: 35,787 ms
+create temporary table edges (like nodes);
+CREATE TABLE
+Time: 11,709 ms
+insert into nodes
+    select 'content', sum(tuples)
+    from counts
+    where tbl in ('content', 'skipped_content');
+INSERT 0 1
+Time: 4,890 ms
+insert into nodes
+    select 'revision', tuples
+    from counts
+    where tbl = 'revision';
+INSERT 0 1
+Time: 2,040 ms
+insert into nodes
+    select 'release', tuples
+    from counts
+    where tbl = 'release';
+INSERT 0 1
+Time: 7,646 ms
+insert into nodes
+    select 'directory', tuples
+    from counts
+    where tbl = 'directory';
+INSERT 0 1
+Time: 64,765 ms
+insert into edges
+    select 'revision->revision', tuples
+    from counts
+    where tbl = 'revision_history';
+INSERT 0 1
+Time: 51,195 ms
+insert into edges
+    select 'revision->directory', tuples
+    from counts
+    where tbl = 'revision';
+INSERT 0 1
+Time: 42,475 ms
+insert into edges
+    select 'release->revision', tuples
+    from counts
+    where tbl = 'release';
+INSERT 0 1
+Time: 21,419 ms
+insert into edges
+    with edges as (
+        select sum(coalesce(cardinality(dir_entries), 0))  as dir_edges,
+               sum(coalesce(cardinality(file_entries), 0)) as file_edges,
+               sum(coalesce(cardinality(rev_entries), 0))  as rev_edges
+        from directory tablesample bernoulli (1.0)
+        )
+    select 'directory->directory' as description,
+           dir_edges * 100 as tuples
+    from edges
+    union
+    select 'directory->file' as description,
+           file_edges * 100 as tuples
+    from edges
+    union
+    select 'directory->revision' as description,
+           rev_edges * 100 as tuples
+    from edges;
+INSERT 0 3
+Time: 2081001,866 ms
+select * from nodes;
+ description |   tuples   
+-------------+------------
+ content     | 2036196307
+ revision    |  468546912
+ release     |    4093895
+ directory   | 1770988032
+(4 rows)
+
+Time: 14,725 ms
+select * from edges;
+     description      |   tuples    
+----------------------+-------------
+ revision->revision   |   483681056
+ revision->directory  |   468546912
+ release->revision    |     4093895
+ directory->directory | 13324743100
+ directory->file      | 20863659500
+ directory->revision  |   132739100
+(6 rows)
+
+Time: 2,515 ms
+select 'nodes' as feat, sum(tuples) as card from nodes
+union
+select 'edges' as feat, sum(tuples) as card from edges;
+ feat  |    card     
+-------+-------------
+ edges | 35277463563
+ nodes |  4279825146
+(2 rows)
+
+Time: 36,392 ms
diff --git a/sql/swh-graph/swh-graph.sql b/sql/swh-graph/swh-graph.sql
new file mode 100644
index 0000000..0b1da02
--- /dev/null
+++ b/sql/swh-graph/swh-graph.sql
@@ -0,0 +1,76 @@
+\timing
+
+create temporary view counts as
+    select relname as tbl, reltuples::bigint as tuples
+    from pg_class
+    where relnamespace = 'public'::regnamespace
+    and relkind = 'r'  -- ordinary table; no indexes, sequences, etc.
+    order by relname;
+
+create temporary table nodes (
+    description  text,
+    tuples       bigint not null
+);
+
+create temporary table edges (like nodes);
+
+insert into nodes
+    select 'content', sum(tuples)
+    from counts
+    where tbl in ('content', 'skipped_content');
+
+insert into nodes
+    select 'revision', tuples
+    from counts
+    where tbl = 'revision';
+
+insert into nodes
+    select 'release', tuples
+    from counts
+    where tbl = 'release';
+
+insert into nodes
+    select 'directory', tuples
+    from counts
+    where tbl = 'directory';
+
+insert into edges
+    select 'revision->revision', tuples
+    from counts
+    where tbl = 'revision_history';
+
+insert into edges
+    select 'revision->directory', tuples
+    from counts
+    where tbl = 'revision';
+
+insert into edges
+    select 'release->revision', tuples
+    from counts
+    where tbl = 'release';
+
+insert into edges
+    with edges as (
+        select sum(coalesce(cardinality(dir_entries), 0))  as dir_edges,
+               sum(coalesce(cardinality(file_entries), 0)) as file_edges,
+               sum(coalesce(cardinality(rev_entries), 0))  as rev_edges
+        from directory tablesample bernoulli (1.0)
+        )
+    select 'directory->directory' as description,
+           dir_edges * 100 as tuples
+    from edges
+    union
+    select 'directory->file' as description,
+           file_edges * 100 as tuples
+    from edges
+    union
+    select 'directory->revision' as description,
+           rev_edges * 100 as tuples
+    from edges;
+
+select * from nodes;
+select * from edges;
+
+select 'nodes' as feat, sum(tuples) as card from nodes
+union
+select 'edges' as feat, sum(tuples) as card from edges;
diff --git a/sql/swh-graph/swh-graph.txt b/sql/swh-graph/swh-graph.txt
new file mode 100644
index 0000000..7780c88
--- /dev/null
+++ b/sql/swh-graph/swh-graph.txt
@@ -0,0 +1,113 @@
+#    -*- mode: org -*-
+#+PROPERTY: header-args :tangle yes
+
+* preamble
+  view to lookup approximate table counts from postgres statistics
+  #+begin_src sql
+    \timing
+
+    create temporary view counts as
+        select relname as tbl, reltuples::bigint as tuples
+        from pg_class
+        where relnamespace = 'public'::regnamespace
+        and relkind = 'r'  -- ordinary table; no indexes, sequences, etc.
+        order by relname;
+
+    create temporary table nodes (
+        description  text,
+        tuples       bigint not null
+    );
+
+    create temporary table edges (like nodes);
+  #+end_src
+* nodes
+** content
+   content nodes (skipped or not) are the leaves in the graph
+   #+begin_src sql
+     insert into nodes
+         select 'content', sum(tuples)
+         from counts
+         where tbl in ('content', 'skipped_content');
+   #+end_src
+** revision
+   revision nodes are the inner nodes of history subgraphs
+   #+begin_src sql
+     insert into nodes
+         select 'revision', tuples
+         from counts
+         where tbl = 'revision';
+   #+end_src
+** release
+   tagged release nodes are graph roots
+   #+begin_src sql
+     insert into nodes
+         select 'release', tuples
+         from counts
+         where tbl = 'release';
+   #+end_src
+** directory
+   anonymous directory nodes
+   #+begin_src sql
+     insert into nodes
+         select 'directory', tuples
+         from counts
+         where tbl = 'directory';
+   #+end_src
+* edges
+** revision
+*** revision -> revision
+    history edges between pairs of revisions
+    #+begin_src sql
+      insert into edges
+          select 'revision->revision', tuples
+          from counts
+          where tbl = 'revision_history';
+    #+end_src
+*** revision -> directory
+    each revision points to a single directory
+    #+begin_src sql
+      insert into edges
+          select 'revision->directory', tuples
+          from counts
+          where tbl = 'revision';
+    #+end_src
+** release -> revision
+   one release edge for each release node
+   #+begin_src sql
+     insert into edges
+         select 'release->revision', tuples
+         from counts
+         where tbl = 'release';
+   #+end_src
+** directories -> { directory, file, revision }
+   one edge for each directory entry (edges pointing to other directories +
+   edges pointing to contents + edges pointing to revisions)
+   #+begin_src sql
+     insert into edges
+         with edges as (
+             select sum(coalesce(cardinality(dir_entries), 0))  as dir_edges,
+                    sum(coalesce(cardinality(file_entries), 0)) as file_edges,
+                    sum(coalesce(cardinality(rev_entries), 0))  as rev_edges
+             from directory tablesample bernoulli (1.0)
+             )
+         select 'directory->directory' as description,
+                dir_edges * 100 as tuples
+         from edges
+         union
+         select 'directory->file' as description,
+                file_edges * 100 as tuples
+         from edges
+         union
+         select 'directory->revision' as description,
+                rev_edges * 100 as tuples
+         from edges;
+   #+end_src
+* totals
+  #+begin_src sql
+    select * from nodes;
+    select * from edges;
+
+    select 'nodes' as feat, sum(tuples) as card from nodes
+    union
+    select 'edges' as feat, sum(tuples) as card from edges;
+  #+end_src