diff --git a/common/images/fork-degree.pdf b/common/images/fork-degree.pdf
new file mode 100644
index 0000000..bdd7037
Binary files /dev/null and b/common/images/fork-degree.pdf differ
diff --git a/common/images/merge-degree.pdf b/common/images/merge-degree.pdf
new file mode 100644
index 0000000..506f0f5
Binary files /dev/null and b/common/images/merge-degree.pdf differ
diff --git a/common/modules/dataset.org b/common/modules/dataset.org
index 3cea4c9..20d0d21 100644
--- a/common/modules/dataset.org
+++ b/common/modules/dataset.org
@@ -1,42 +1,91 @@
 #+COLUMNS: %40ITEM %10BEAMER_env(Env) %9BEAMER_envargs(Env Args) %10BEAMER_act(Act) %4BEAMER_col(Col) %10BEAMER_extra(Extra) %8BEAMER_opt(Opt)
 #+INCLUDE: "prelude.org" :minlevel 1
 
 * Open Datasets
   :PROPERTIES:
   :CUSTOM_ID: main
   :END:
 ** Software Heritage Graph dataset
    :PROPERTIES:
    :CUSTOM_ID: graphdataset
    :END:
-
    #+BEAMER: \vspace{-1mm}
 
    **Use case:** large scale analyses of the most comprehensive corpus on the
    development history of free/open source software.
 
 *** Dataset
     - Relational representation of the full graph as a set of tables
     - Available as open data: https://doi.org/10.5281/zenodo.2583978
 
   #+BEAMER: \vspace{-1mm}
-
 *** Formats
     - Local use: PostgreSQL dumps, or Apache Parquet files (~1 TiB each)
     - Live usage: Amazon Athena (SQL-queriable)
 
   #+BEAMER: \vspace{-1mm}
-
 *** References and sample queries
     #+BEGIN_EXPORT latex
     \vspace{-2mm}
     \footnotesize
     \begin{thebibliography}{Foo Bar, 1969}
-
     \bibitem{Pietri2019} Antoine Pietri, Diomidis Spinellis, Stefano Zacchiroli\newblock
     The Software Heritage Graph Dataset: Public software development under one roof\newblock
     MSR 2019: Intl. Conf. on Mining Software Repositories, IEEE\newblock
     non-paywalled preprint: \url{http://deb.li/swhmsr19}
-
     \end{thebibliography}
     #+END_EXPORT
+
+** Graph dataset --- sample queries
+   :PROPERTIES:
+   :CUSTOM_ID: graphquery1
+   :END:
+*** Most frequent first commit words
+    #+begin_src sql
+    SELECT COUNT(*) AS c, word FROM (
+      SELECT LOWER(REGEXP_EXTRACT(FROM_UTF8(
+      message), 'ˆ\w+')) AS word FROM revision)
+    WHERE word != ''
+    GROUP BY word ORDER BY COUNT(*) DESC LIMIT 5;
+    #+end_src
+*** 
+    |      Count | Word   |
+    |------------+--------|
+    | 71'338'310 | update |
+    | 64'980'346 | merge  |
+    | 56'854'372 | add    |
+    | 44'971'954 | added  |
+    | 33'222'056 | fix    |
+
+** Graph dataset --- sample queries
+   :PROPERTIES:
+   :CUSTOM_ID: graphquery2
+   :END:
+*** Fork arity
+    :PROPERTIES:
+    :BEAMER_env: block
+    :BEAMER_COL: 0.5
+    :END:
+    i.e., how often is a commit based upon?
+    #+BEAMER: \scriptsize
+    #+begin_src sql
+    SELECT fork_deg, count(*) FROM (
+      SELECT id, count(*) AS fork_deg
+      FROM revision_history GROUP BY id) t
+    GROUP BY fork_deg ORDER BY fork_deg;
+    #+end_src
+    #+BEAMER: \includegraphics[width=\linewidth]{fork-degree}
+*** Merge arity
+    :PROPERTIES:
+    :BEAMER_env: block
+    :BEAMER_COL: 0.5
+    :END:
+    i.e., how large are merges?
+    #+BEAMER: \scriptsize
+    #+begin_src sql
+    SELECT merge_deg, COUNT(*) FROM (
+      SELECT parent_id, COUNT(*) AS merge_deg
+      FROM revision_history GROUP BY parent_id) t
+    GROUP BY deg ORDER BY deg;
+    #+end_src
+    #+BEAMER: \includegraphics[width=\linewidth]{merge-degree}