diff --git a/dbms/src/DataStreams/FormatFactory.cpp b/dbms/src/DataStreams/FormatFactory.cpp
index f3ab160812a..ea77f3b2c09 100644
--- a/dbms/src/DataStreams/FormatFactory.cpp
+++ b/dbms/src/DataStreams/FormatFactory.cpp
@@ -148,7 +148,9 @@ static BlockOutputStreamPtr getOutputImpl(const String & name, WriteBuffer & buf
     else if (name == "PrettyCompactMonoBlock")
     {
         BlockOutputStreamPtr dst = std::make_shared<PrettyCompactBlockOutputStream>(buf, false, settings.output_format_pretty_max_rows, context);
-        return std::make_shared<SquashingBlockOutputStream>(dst, settings.output_format_pretty_max_rows, 0);
+        auto res = std::make_shared<SquashingBlockOutputStream>(dst, settings.output_format_pretty_max_rows, 0);
+        res->disableFlush();
+        return res;
     }
     else if (name == "PrettySpace")
         return std::make_shared<PrettySpaceBlockOutputStream>(buf, false, settings.output_format_pretty_max_rows, context);
diff --git a/dbms/src/DataStreams/PrettyBlockOutputStream.cpp b/dbms/src/DataStreams/PrettyBlockOutputStream.cpp
index c7eee1fe4eb..f6a7dab3081 100644
--- a/dbms/src/DataStreams/PrettyBlockOutputStream.cpp
+++ b/dbms/src/DataStreams/PrettyBlockOutputStream.cpp
@@ -60,7 +60,7 @@ void PrettyBlockOutputStream::calculateWidths(const Block & block, WidthsPerColu
             {
                 {
                     WriteBufferFromString out(serialized_value);
-                    elem.type->serializeTextEscaped(*elem.column, i, out);
+                    elem.type->serializeTextEscaped(*elem.column, j, out);
                 }
 
                 widths[i][j] = UTF8::countCodePoints(reinterpret_cast<const UInt8 *>(serialized_value.data()), serialized_value.size());
diff --git a/dbms/src/DataStreams/PrettyBlockOutputStream.h b/dbms/src/DataStreams/PrettyBlockOutputStream.h
index a6be5b8f7f5..9c6eef51705 100644
--- a/dbms/src/DataStreams/PrettyBlockOutputStream.h
+++ b/dbms/src/DataStreams/PrettyBlockOutputStream.h
@@ -44,7 +44,7 @@ protected:
     const Context & context;
 
     using Widths = PODArray<size_t>;
-    using WidthsPerColumn = PODArray<Widths>;
+    using WidthsPerColumn = std::vector<Widths>;
 
     static void calculateWidths(const Block & block, WidthsPerColumn & widths, Widths & max_widths, Widths & name_widths);
     void writeValueWithPadding(const ColumnWithTypeAndName & elem, size_t row_num, size_t value_width, size_t pad_to_width);
diff --git a/dbms/src/DataStreams/SquashingBlockOutputStream.cpp b/dbms/src/DataStreams/SquashingBlockOutputStream.cpp
index 2826f1efb56..ff340926c90 100644
--- a/dbms/src/DataStreams/SquashingBlockOutputStream.cpp
+++ b/dbms/src/DataStreams/SquashingBlockOutputStream.cpp
@@ -33,7 +33,8 @@ void SquashingBlockOutputStream::finalize()
 
 void SquashingBlockOutputStream::flush()
 {
-    finalize();
+    if (!disable_flush)
+        finalize();
     output->flush();
 }
 
diff --git a/dbms/src/DataStreams/SquashingBlockOutputStream.h b/dbms/src/DataStreams/SquashingBlockOutputStream.h
index 895356638fa..df3cf262fa6 100644
--- a/dbms/src/DataStreams/SquashingBlockOutputStream.h
+++ b/dbms/src/DataStreams/SquashingBlockOutputStream.h
@@ -20,6 +20,9 @@ public:
     void writePrefix() override;
     void writeSuffix() override;
 
+    /// Don't write blocks less than specified size even when flush method was called by user.
+    void disableFlush() { disable_flush = true; }
+
 private:
     BlockOutputStreamPtr output;
 
@@ -27,6 +30,8 @@ private:
     bool all_written = false;
 
     void finalize();
+
+    bool disable_flush = false;
 };
 
 }