From 30464ccef78e6cd70de83fd6ef9d3f009aa70a11 Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Mon, 15 Jul 2019 19:19:25 +0300
Subject: [PATCH 1/2] Remove flapping uniqCombined(>= 19) tests

---
 dbms/tests/performance/uniq.xml | 2 --
 1 file changed, 2 deletions(-)

diff --git a/dbms/tests/performance/uniq.xml b/dbms/tests/performance/uniq.xml
index af41d1c79e5..c44a4e2ca58 100644
--- a/dbms/tests/performance/uniq.xml
+++ b/dbms/tests/performance/uniq.xml
@@ -46,8 +46,6 @@
                <value>uniqCombined(16)</value>
                <value>uniqCombined(17)</value>
                <value>uniqCombined(18)</value>
-               <value>uniqCombined(19)</value>
-               <value>uniqCombined(20)</value>
                <value>uniqUpTo(3)</value>
                <value>uniqUpTo(5)</value>
                <value>uniqUpTo(10)</value>

From ced2721ce85bc8c8f51b0ce666cdff9ad2c3b132 Mon Sep 17 00:00:00 2001
From: Nikolai Kochetov <KochetovNicolai@users.noreply.github.com>
Date: Mon, 15 Jul 2019 19:20:21 +0300
Subject: [PATCH 2/2] Fix deserializeAndInsertFromArena. (#5973)

---
 dbms/src/Columns/ColumnArray.cpp    | 13 +++++++++----
 dbms/src/Columns/ColumnNullable.cpp |  9 +++++----
 dbms/src/Columns/ColumnTuple.cpp    | 10 +++++++---
 dbms/src/Columns/ColumnUnique.h     | 18 +++++++++---------
 4 files changed, 30 insertions(+), 20 deletions(-)

diff --git a/dbms/src/Columns/ColumnArray.cpp b/dbms/src/Columns/ColumnArray.cpp
index b4382755ba3..b825342ee5f 100644
--- a/dbms/src/Columns/ColumnArray.cpp
+++ b/dbms/src/Columns/ColumnArray.cpp
@@ -178,11 +178,16 @@ StringRef ColumnArray::serializeValueIntoArena(size_t n, Arena & arena, char con
     char * pos = arena.allocContinue(sizeof(array_size), begin);
     memcpy(pos, &array_size, sizeof(array_size));
 
-    size_t values_size = 0;
-    for (size_t i = 0; i < array_size; ++i)
-        values_size += getData().serializeValueIntoArena(offset + i, arena, begin).size;
+    StringRef res(pos, sizeof(array_size));
 
-    return StringRef(begin, sizeof(array_size) + values_size);
+    for (size_t i = 0; i < array_size; ++i)
+    {
+        auto value_ref = getData().serializeValueIntoArena(offset + i, arena, begin);
+        res.data = value_ref.data - res.size;
+        res.size += value_ref.size;
+    }
+
+    return res;
 }
 
 
diff --git a/dbms/src/Columns/ColumnNullable.cpp b/dbms/src/Columns/ColumnNullable.cpp
index 3ae692552e8..c5cdffba84d 100644
--- a/dbms/src/Columns/ColumnNullable.cpp
+++ b/dbms/src/Columns/ColumnNullable.cpp
@@ -103,12 +103,13 @@ StringRef ColumnNullable::serializeValueIntoArena(size_t n, Arena & arena, char
     auto pos = arena.allocContinue(s, begin);
     memcpy(pos, &arr[n], s);
 
-    size_t nested_size = 0;
+    if (arr[n])
+        return StringRef(pos, s);
 
-    if (arr[n] == 0)
-        nested_size = getNestedColumn().serializeValueIntoArena(n, arena, begin).size;
+    auto nested_ref = getNestedColumn().serializeValueIntoArena(n, arena, begin);
 
-    return StringRef{begin, s + nested_size};
+    /// serializeValueIntoArena may reallocate memory. Have to use ptr from nested_ref.data and move it back.
+    return StringRef(nested_ref.data - s, nested_ref.size + s);
 }
 
 const char * ColumnNullable::deserializeAndInsertFromArena(const char * pos)
diff --git a/dbms/src/Columns/ColumnTuple.cpp b/dbms/src/Columns/ColumnTuple.cpp
index f7a95c1ac9f..3ad7f007edf 100644
--- a/dbms/src/Columns/ColumnTuple.cpp
+++ b/dbms/src/Columns/ColumnTuple.cpp
@@ -142,11 +142,15 @@ void ColumnTuple::popBack(size_t n)
 
 StringRef ColumnTuple::serializeValueIntoArena(size_t n, Arena & arena, char const *& begin) const
 {
-    size_t values_size = 0;
+    StringRef res(begin, 0);
     for (auto & column : columns)
-        values_size += column->serializeValueIntoArena(n, arena, begin).size;
+    {
+        auto value_ref = column->serializeValueIntoArena(n, arena, begin);
+        res.data = value_ref.data - res.size;
+        res.size += value_ref.size;
+    }
 
-    return StringRef(begin, values_size);
+    return res;
 }
 
 const char * ColumnTuple::deserializeAndInsertFromArena(const char * pos)
diff --git a/dbms/src/Columns/ColumnUnique.h b/dbms/src/Columns/ColumnUnique.h
index febdeaafa95..0c5efd8058d 100644
--- a/dbms/src/Columns/ColumnUnique.h
+++ b/dbms/src/Columns/ColumnUnique.h
@@ -300,19 +300,19 @@ StringRef ColumnUnique<ColumnType>::serializeValueIntoArena(size_t n, Arena & ar
 {
     if (is_nullable)
     {
-        const UInt8 null_flag = 1;
-        const UInt8 not_null_flag = 0;
+        static constexpr auto s = sizeof(UInt8);
 
-        auto pos = arena.allocContinue(sizeof(null_flag), begin);
-        auto & flag = (n == getNullValueIndex() ? null_flag : not_null_flag);
-        memcpy(pos, &flag, sizeof(flag));
+        auto pos = arena.allocContinue(s, begin);
+        UInt8 flag = (n == getNullValueIndex() ? 1 : 0);
+        unalignedStore<UInt8>(pos, flag);
 
-        size_t nested_size = 0;
+        if (n == getNullValueIndex())
+            return StringRef(pos, s);
 
-        if (n != getNullValueIndex())
-            nested_size = column_holder->serializeValueIntoArena(n, arena, begin).size;
+        auto nested_ref = column_holder->serializeValueIntoArena(n, arena, begin);
 
-        return StringRef(pos, sizeof(null_flag) + nested_size);
+        /// serializeValueIntoArena may reallocate memory. Have to use ptr from nested_ref.data and move it back.
+        return StringRef(nested_ref.data - s, nested_ref.size + s);
     }
 
     return column_holder->serializeValueIntoArena(n, arena, begin);