From 3429274de14a95ade6df28e940b1d78c56c346b3 Mon Sep 17 00:00:00 2001
From: Nikolai Kochetov <nik-kochetov@yandex-team.ru>
Date: Mon, 12 Nov 2018 11:40:23 +0300
Subject: [PATCH] Fix perf in IColumnUnique::size func. #3256

---
 dbms/src/Columns/IColumnUnique.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dbms/src/Columns/IColumnUnique.h b/dbms/src/Columns/IColumnUnique.h
index 62aef93eef1..7e5f3976dce 100644
--- a/dbms/src/Columns/IColumnUnique.h
+++ b/dbms/src/Columns/IColumnUnique.h
@@ -23,7 +23,7 @@ public:
     /// Uses thread-safe cache.
     virtual const UInt64 * tryGetSavedHash() const = 0;
 
-    size_t size() const override { return getNestedColumn()->size(); }
+    size_t size() const override { return getNestedNotNullableColumn()->size(); }
 
     /// Appends new value at the end of column (column's size is increased by 1).
     /// Is used to transform raw strings to Blocks (for example, inside input format parsers)