diff --git a/sql/20e_undo.sql b/sql/20e_undo.sql
new file mode 100644
index 0000000..4d2053a
--- /dev/null
+++ b/sql/20e_undo.sql
@@ -0,0 +1,43 @@
+prompt <h3>Détail du tablespace UNDO : </h3>
+
+SELECT
+    a.tablespace_name,
+    a.file_id,
+    a.bytes / 1024 / 1024 AS size_mb,
+    a.autoextensible,
+    b.bytes_free / 1024 / 1024 AS free_mb,
+    (a.bytes - b.bytes_free) / 1024 / 1024 AS used_mb,
+    ROUND(((a.bytes - b.bytes_free) / a.bytes) * 100, 2) AS pct_used
+FROM
+    dba_data_files a
+JOIN
+    (SELECT file_id, SUM(bytes) AS bytes_free
+     FROM dba_free_space
+     GROUP BY file_id) b
+ON a.file_id = b.file_id
+WHERE a.tablespace_name like 'UNDO%';  -- ou le nom réel de ton UNDO
+
+prompt <h3>Durée de rétention UNDO : </h3>
+SELECT
+    retention,
+    tuned_undoretention,
+    undoblks,
+    expiredblks,
+    unexpiredblks,
+    tuned_undoretention
+FROM
+    v$undostat
+ORDER BY
+    begin_time DESC FETCH FIRST 10 ROWS ONLY;
+
+prompt <h3>Occupation de l’espace dans le UNDO par session : </h3>
+SELECT
+    s.sid,
+    s.serial#,
+    u.name AS username,
+    t.used_urec,
+    t.used_ublk
+FROM
+    v$transaction t
+JOIN v$session s ON t.ses_addr = s.saddr
+JOIN all_users u ON s.user# = u.user_id;