Update cumulative-unique.md

content/en/altinity-kb-queries-and-syntax/cumulative-unique.md

@@ -20,23 +20,14 @@ INSERT INTO events SELECT
 FROM numbers(15);
 ```
 
-## Using arrays
+## Using window functions (starting from Clickhouse 21.3)
 
 ```sql
-WITH
-    groupArray(_ts) AS ts_arr,
-    groupArray(state) AS state_arr
 SELECT
-    arrayJoin(ts_arr) AS ts,
-    arrayReduce('uniqExactMerge', arrayFilter((x, y) -> (y <= ts), state_arr, ts_arr)) AS uniq
-FROM
-(
-    SELECT
-        toStartOfDay(ts) AS _ts,
-        uniqExactState(user_id) AS state
-    FROM events
-    GROUP BY _ts
-)
+    toStartOfDay(ts) AS ts,
+    uniqExactMerge(uniqExactState(user_id)) OVER (ORDER BY ts ASC ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS uniq
+FROM events
+GROUP BY ts
 ORDER BY ts ASC
 
 ┌──────────────────ts─┬─uniq─┐
@@ -47,19 +38,17 @@ ORDER BY ts ASC
 │ 2021-05-03 00:00:00 │    7 │
 └─────────────────────┴──────┘
 
-WITH arrayJoin(range(toUInt32(_ts) AS int, least(int + toUInt32((3600 * 24) * 5), toUInt32(toDateTime('2021-05-04 00:00:00'))), 3600 * 24)) AS ts_expanded
 SELECT
-    toDateTime(ts_expanded) AS ts,
-    uniqExactMerge(state) AS uniq
+    ts,
+    uniqExactMerge(state) OVER (ORDER BY ts ASC ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS uniq
 FROM
 (
     SELECT
-        toStartOfDay(ts) AS _ts,
+        toStartOfDay(ts) AS ts,
         uniqExactState(user_id) AS state
     FROM events
-    GROUP BY _ts
+    GROUP BY ts
 )
-GROUP BY ts
 ORDER BY ts ASC
 
 ┌──────────────────ts─┬─uniq─┐
@@ -71,14 +60,23 @@ ORDER BY ts ASC
 └─────────────────────┴──────┘
 ```
 
-## Using window functions (starting from Clickhouse 21.3)
+## Using arrays
 
 ```sql
+WITH
+    groupArray(_ts) AS ts_arr,
+    groupArray(state) AS state_arr
 SELECT
-    toStartOfDay(ts) AS ts,
-    uniqExactMerge(uniqExactState(user_id)) OVER (ORDER BY ts ASC ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS uniq
-FROM events
-GROUP BY ts
+    arrayJoin(ts_arr) AS ts,
+    arrayReduce('uniqExactMerge', arrayFilter((x, y) -> (y <= ts), state_arr, ts_arr)) AS uniq
+FROM
+(
+    SELECT
+        toStartOfDay(ts) AS _ts,
+        uniqExactState(user_id) AS state
+    FROM events
+    GROUP BY _ts
+)
 ORDER BY ts ASC
 
 ┌──────────────────ts─┬─uniq─┐
@@ -89,17 +87,19 @@ ORDER BY ts ASC
 │ 2021-05-03 00:00:00 │    7 │
 └─────────────────────┴──────┘
 
+WITH arrayJoin(range(toUInt32(_ts) AS int, least(int + toUInt32((3600 * 24) * 5), toUInt32(toDateTime('2021-05-04 00:00:00'))), 3600 * 24)) AS ts_expanded
 SELECT
-    ts,
-    uniqExactMerge(state) OVER (ORDER BY ts ASC ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS uniq
+    toDateTime(ts_expanded) AS ts,
+    uniqExactMerge(state) AS uniq
 FROM
 (
     SELECT
-        toStartOfDay(ts) AS ts,
+        toStartOfDay(ts) AS _ts,
         uniqExactState(user_id) AS state
     FROM events
-    GROUP BY ts
+    GROUP BY _ts
 )
+GROUP BY ts
 ORDER BY ts ASC
 
 ┌──────────────────ts─┬─uniq─┐