Incorporate feedback

Author: rschu1ze

docs/getting-started/example-datasets/tpch.md

@@ -234,7 +234,7 @@ ORDER BY
 **Q2**
 
 ```sql
-SET allow_experimental_correlated_subqueries = 1;
+SET allow_experimental_correlated_subqueries = 1; -- since v25.5
 
 SELECT
     s_acctbal,
@@ -281,6 +281,62 @@ ORDER BY
     p_partkey;
 ```
 
+::::note
+Until v25.5, the query did not work out-of-the box due to correlated subqueries. Corresponding issue: https://github.com/ClickHouse/ClickHouse/issues/6697
+
+This alternative formulation works and was verified to return the reference results.
+
+```sql
+WITH MinSupplyCost AS (
+    SELECT
+        ps_partkey,
+        MIN(ps_supplycost) AS min_supplycost
+    FROM
+        partsupp ps
+    JOIN
+        supplier s ON ps.ps_suppkey = s.s_suppkey
+    JOIN
+        nation n ON s.s_nationkey = n.n_nationkey
+    JOIN
+        region r ON n.n_regionkey = r.r_regionkey
+    WHERE
+        r.r_name = 'EUROPE'
+    GROUP BY
+        ps_partkey
+)
+SELECT
+    s.s_acctbal,
+    s.s_name,
+    n.n_name,
+    p.p_partkey,
+    p.p_mfgr,
+    s.s_address,
+    s.s_phone,
+    s.s_comment
+FROM
+    part p
+JOIN
+    partsupp ps ON p.p_partkey = ps.ps_partkey
+JOIN
+    supplier s ON s.s_suppkey = ps.ps_suppkey
+JOIN
+    nation n ON s.s_nationkey = n.n_nationkey
+JOIN
+    region r ON n.n_regionkey = r.r_regionkey
+JOIN
+    MinSupplyCost msc ON ps.ps_partkey = msc.ps_partkey AND ps.ps_supplycost = msc.min_supplycost
+WHERE
+    p.p_size = 15
+    AND p.p_type LIKE '%BRASS'
+    AND r.r_name = 'EUROPE'
+ORDER BY
+    s.s_acctbal DESC,
+    n.n_name,
+    s.s_name,
+    p.p_partkey;
+```
+::::
+
 **Q3**
 
 ```sql
@@ -311,7 +367,7 @@ ORDER BY
 **Q4**
 
 ```sql
-SET allow_experimental_correlated_subqueries = 1;
+SET allow_experimental_correlated_subqueries = 1; -- since v25.5
 
 SELECT
     o_orderpriority,
@@ -336,6 +392,39 @@ ORDER BY
     o_orderpriority;
 ```
 
+::::note
+Until v25.5, the query did not work out-of-the box due to correlated subqueries. Corresponding issue: https://github.com/ClickHouse/ClickHouse/issues/6697
+
+This alternative formulation works and was verified to return the reference results.
+
+```sql
+WITH ValidLineItems AS (
+    SELECT
+        l_orderkey
+    FROM
+        lineitem
+    WHERE
+        l_commitdate < l_receiptdate
+    GROUP BY
+        l_orderkey
+)
+SELECT
+    o.o_orderpriority,
+    COUNT(*) AS order_count
+FROM
+    orders o
+JOIN
+    ValidLineItems vli ON o.o_orderkey = vli.l_orderkey
+WHERE
+    o.o_orderdate >= DATE '1993-07-01'
+    AND o.o_orderdate < DATE '1993-07-01' + INTERVAL '3' MONTH
+GROUP BY
+    o.o_orderpriority
+ORDER BY
+    o.o_orderpriority;
+```
+::::
+
 **Q5**
 
 ```sql
@@ -738,7 +827,7 @@ ORDER BY
 **Q17**
 
 ```sql
-SET allow_experimental_correlated_subqueries = 1;
+SET allow_experimental_correlated_subqueries = 1; -- since v25.5
 
 SELECT
     sum(l_extendedprice) / 7.0 AS avg_yearly
@@ -759,6 +848,37 @@ WHERE
     );
 ```
 
+::::note
+Until v25.5, the query did not work out-of-the box due to correlated subqueries. Corresponding issue: https://github.com/ClickHouse/ClickHouse/issues/6697
+
+This alternative formulation works and was verified to return the reference results.
+
+```sql
+WITH AvgQuantity AS (
+    SELECT
+        l_partkey,
+        AVG(l_quantity) * 0.2 AS avg_quantity
+    FROM
+        lineitem
+    GROUP BY
+        l_partkey
+)
+SELECT
+    SUM(l.l_extendedprice) / 7.0 AS avg_yearly
+FROM
+    lineitem l
+JOIN
+    part p ON p.p_partkey = l.l_partkey
+JOIN
+    AvgQuantity aq ON l.l_partkey = aq.l_partkey
+WHERE
+    p.p_brand = 'Brand#23'
+    AND p.p_container = 'MED BOX'
+    AND l.l_quantity < aq.avg_quantity;
+
+```
+::::
+
 **Q18**
 
 ```sql
@@ -840,7 +960,7 @@ WHERE
 **Q20**
 
 ```sql
-SET allow_experimental_correlated_subqueries = 1;
+SET allow_experimental_correlated_subqueries = 1; -- since v25.5
 
 SELECT
     s_name,
@@ -881,10 +1001,14 @@ ORDER BY
     s_name;
 ```
 
+::::note
+Until v25.5, the query did not work out-of-the box due to correlated subqueries. Corresponding issue: https://github.com/ClickHouse/ClickHouse/issues/6697
+::::
+
 **Q21**
 
 ```sql
-SET allow_experimental_correlated_subqueries = 1;
+SET allow_experimental_correlated_subqueries = 1; -- since v25.5
 
 SELECT
     s_name,
@@ -926,11 +1050,14 @@ ORDER BY
     numwait DESC,
     s_name;
 ```
+::::note
+Until v25.5, the query did not work out-of-the box due to correlated subqueries. Corresponding issue: https://github.com/ClickHouse/ClickHouse/issues/6697
+::::
 
 **Q22**
 
 ```sql
-SET allow_experimental_correlated_subqueries = 1;
+SET allow_experimental_correlated_subqueries = 1; -- since v25.5
 
 SELECT
     cntrycode,
@@ -969,3 +1096,7 @@ GROUP BY
 ORDER BY
     cntrycode;
 ```
+
+::::note
+Until v25.5, the query did not work out-of-the box due to correlated subqueries. Corresponding issue: https://github.com/ClickHouse/ClickHouse/issues/6697
+::::