From 7febe64c82dbe22bf7cbcfec8e2274d38c351971 Mon Sep 17 00:00:00 2001
From: Alexey Milovidov <milovidov@yandex-team.ru>
Date: Wed, 21 Nov 2018 06:19:29 +0300
Subject: [PATCH] Failproof #3589

---
 dbms/src/DataTypes/DataTypeString.cpp | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/dbms/src/DataTypes/DataTypeString.cpp b/dbms/src/DataTypes/DataTypeString.cpp
index 166f1f6fb4f..2023523aa41 100644
--- a/dbms/src/DataTypes/DataTypeString.cpp
+++ b/dbms/src/DataTypes/DataTypeString.cpp
@@ -187,17 +187,23 @@ void DataTypeString::deserializeBinaryBulk(IColumn & column, ReadBuffer & istr,
         avg_chars_size = (avg_value_size_hint - sizeof(offsets[0])) * avg_value_size_hint_reserve_multiplier;
     }
 
-    try
+    size_t size_to_reserve = data.size() + std::ceil(limit * avg_chars_size);
+
+    /// Never reserve for too big size.
+    if (size_to_reserve < 256 * 1024 * 1024)
     {
-        data.reserve(data.size() + std::ceil(limit * avg_chars_size));
-    }
-    catch (Exception & e)
-    {
-        e.addMessage(
-            "(avg_value_size_hint = " + toString(avg_value_size_hint)
-            + ", avg_chars_size = " + toString(avg_chars_size)
-            + ", limit = " + toString(limit) + ")");
-        throw;
+        try
+        {
+            data.reserve(size_to_reserve);
+        }
+        catch (Exception & e)
+        {
+            e.addMessage(
+                "(avg_value_size_hint = " + toString(avg_value_size_hint)
+                + ", avg_chars_size = " + toString(avg_chars_size)
+                + ", limit = " + toString(limit) + ")");
+            throw;
+        }
     }
 
     offsets.reserve(offsets.size() + limit);