data layer

data-layer/infra/clickhouse/session_analysis.sql.tmpl

@@ -0,0 +1,52 @@
+-- Session Analysis -- split each user's event stream into sessions based on
+-- inactivity gap, then aggregate per session.
+--
+-- Required parameters (clickhouse.Named):
+--   workspace_id    : String
+--   from            : DateTime64(3,'UTC')
+--   to              : DateTime64(3,'UTC')
+--   timeout_seconds : UInt32
+--   limit           : UInt32
+--   offset          : UInt32
+--
+-- Optional parameters (template-driven):
+--   user_id : String   (when .HasUserID)
+SELECT
+    user_id,
+    session_index                              AS session_id,
+    min(timestamp)                             AS started_at,
+    max(timestamp)                             AS ended_at,
+    count()                                    AS events,
+    dateDiff('second', min(timestamp), max(timestamp)) AS duration_seconds
+FROM (
+    SELECT
+        user_id,
+        timestamp,
+        sum(is_new_session) OVER (PARTITION BY user_id ORDER BY timestamp) AS session_index
+    FROM (
+        SELECT
+            user_id,
+            timestamp,
+            if(
+                dateDiff(
+                    'second',
+                    lagInFrame(timestamp) OVER (PARTITION BY user_id ORDER BY timestamp),
+                    timestamp
+                ) > {timeout_seconds:UInt32},
+                1,
+                0
+            ) AS is_new_session
+        FROM events_track
+        WHERE workspace_id = {workspace_id:String}
+          AND received_at >= {from:DateTime64(3,'UTC')}
+          AND received_at <  {to:DateTime64(3,'UTC')}
+          AND user_id != ''
+{{- if .HasUserID }}
+          AND user_id = {user_id:String}
+{{- end }}
+    )
+)
+GROUP BY user_id, session_index
+ORDER BY started_at DESC
+LIMIT {limit:UInt32}
+OFFSET {offset:UInt32}