From df6860d5e089aeb3e6fe1f91836c62162a11f9a1 Mon Sep 17 00:00:00 2001
From: "Constantin S. Pan" <kvapen@gmail.com>
Date: Fri, 15 Mar 2019 15:22:22 +0000
Subject: [PATCH] Make the query planner respect LIMIT BY in remote queries

---
 dbms/src/Interpreters/InterpreterSelectQuery.cpp            | 6 ++++++
 .../queries/0_stateless/00409_shard_limit_by.reference      | 5 +++++
 dbms/tests/queries/0_stateless/00409_shard_limit_by.sql     | 3 +++
 3 files changed, 14 insertions(+)

diff --git a/dbms/src/Interpreters/InterpreterSelectQuery.cpp b/dbms/src/Interpreters/InterpreterSelectQuery.cpp
index 83d53ca37b8..a76d3405533 100644
--- a/dbms/src/Interpreters/InterpreterSelectQuery.cpp
+++ b/dbms/src/Interpreters/InterpreterSelectQuery.cpp
@@ -623,6 +623,12 @@ void InterpreterSelectQuery::executeImpl(Pipeline & pipeline, const BlockInputSt
                 if (expressions.has_order_by && query.limit_length)
                     executeDistinct(pipeline, false, expressions.selected_columns);
 
+                if (expressions.has_limit_by)
+                {
+                    executeExpression(pipeline, expressions.before_limit_by);
+                    executeLimitBy(pipeline);
+                }
+
                 if (query.limit_length)
                     executePreLimit(pipeline);
             }
diff --git a/dbms/tests/queries/0_stateless/00409_shard_limit_by.reference b/dbms/tests/queries/0_stateless/00409_shard_limit_by.reference
index f0f6c4e48ad..8aa9b8f42c0 100644
--- a/dbms/tests/queries/0_stateless/00409_shard_limit_by.reference
+++ b/dbms/tests/queries/0_stateless/00409_shard_limit_by.reference
@@ -19,3 +19,8 @@
 0
 0
 1
+100
+100
+101
+101
+102
diff --git a/dbms/tests/queries/0_stateless/00409_shard_limit_by.sql b/dbms/tests/queries/0_stateless/00409_shard_limit_by.sql
index 982cff9a6c5..57d9182a9c8 100644
--- a/dbms/tests/queries/0_stateless/00409_shard_limit_by.sql
+++ b/dbms/tests/queries/0_stateless/00409_shard_limit_by.sql
@@ -29,4 +29,7 @@ SELECT dummy FROM remote('127.0.0.{2,3}', system.one) LIMIT 2 BY dummy;
 
 SELECT 1 as one FROM remote('127.0.0.{2,3}', system.one) LIMIT 1 BY one;
 
+-- Distributed LIMIT BY with LIMIT
+SELECT toInt8(number / 5 + 100) AS x FROM remote('127.0.0.1', system.numbers) LIMIT 2 BY x LIMIT 5;
+
 DROP TABLE IF EXISTS test.limit_by;