diff --git a/dbms/src/Dictionaries/LibraryDictionarySource.cpp b/dbms/src/Dictionaries/LibraryDictionarySource.cpp
index d9acef989c8..00a216686c0 100644
--- a/dbms/src/Dictionaries/LibraryDictionarySource.cpp
+++ b/dbms/src/Dictionaries/LibraryDictionarySource.cpp
@@ -208,25 +208,30 @@ BlockInputStreamPtr LibraryDictionarySource::loadKeys(const Columns & key_column
 {
     LOG_TRACE(log, "loadKeys " << toString() << " size = " << requested_rows.size());
 
-    auto columns_holder = std::make_unique<ClickHouseLibrary::CString[]>(key_columns.size());
-    ClickHouseLibrary::CStrings columns_pass{
-        static_cast<decltype(ClickHouseLibrary::CStrings::data)>(columns_holder.get()), key_columns.size()};
-    size_t key_columns_n = 0;
-    for (auto & column : key_columns)
+    auto holder = std::make_unique<ClickHouseLibrary::Row[]>(key_columns.size());
+    std::vector<std::unique_ptr<ClickHouseLibrary::Field[]>> columnDataHolders;
+    for (size_t i = 0; i < key_columns.size(); ++i)
     {
-        columns_pass.data[key_columns_n] = column->getName().c_str();
-        ++key_columns_n;
-    }
-    const ClickHouseLibrary::VectorUInt64 requested_rows_c{
-        ext::bit_cast<decltype(ClickHouseLibrary::VectorUInt64::data)>(requested_rows.data()), requested_rows.size()};
-    void * data_ptr = nullptr;
+        auto cellHolder = std::make_unique<ClickHouseLibrary::Field[]>(requested_rows.size());
+        for (size_t j = 0; j < requested_rows.size(); ++j)
+        {
+            auto dataRef = key_columns[i]->getDataAt(requested_rows[j]);
+            cellHolder[j] = ClickHouseLibrary::Field{.data = static_cast<const void *>(dataRef.data), .size = dataRef.size};
+        }
+        holder[i]
+            = ClickHouseLibrary::Row{.data = static_cast<ClickHouseLibrary::Field *>(cellHolder.get()), .size = requested_rows.size()};
 
+        columnDataHolders.push_back(std::move(cellHolder));
+    }
+
+    ClickHouseLibrary::Table requestCols{.data = static_cast<ClickHouseLibrary::Row *>(holder.get()), .size = key_columns.size()};
+
+    void * data_ptr = nullptr;
     /// Get function pointer before dataNew call because library->get may throw.
-    auto func_loadKeys
-        = library->get<void * (*)(decltype(data_ptr), decltype(&settings->strings), decltype(&columns_pass), decltype(&requested_rows_c))>(
-            "ClickHouseDictionary_v3_loadKeys");
+    auto func_loadKeys = library->get<void * (*)(decltype(data_ptr), decltype(&settings->strings), decltype(&requestCols))>(
+        "ClickHouseDictionary_v3_loadKeys");
     data_ptr = library->get<decltype(data_ptr) (*)(decltype(lib_data))>("ClickHouseDictionary_v3_dataNew")(lib_data);
-    auto data = func_loadKeys(data_ptr, &settings->strings, &columns_pass, &requested_rows_c);
+    auto data = func_loadKeys(data_ptr, &settings->strings, &requestCols);
     auto block = dataToBlock(description.sample_block, data);
     SCOPE_EXIT(library->get<void (*)(decltype(lib_data), decltype(data_ptr))>("ClickHouseDictionary_v3_dataDelete")(lib_data, data_ptr));
     return std::make_shared<OneBlockInputStream>(block);
diff --git a/dbms/tests/external_dictionaries/dictionary_library/dictionary_library.cpp b/dbms/tests/external_dictionaries/dictionary_library/dictionary_library.cpp
index 8e18abbe80f..59b75d0a26f 100644
--- a/dbms/tests/external_dictionaries/dictionary_library/dictionary_library.cpp
+++ b/dbms/tests/external_dictionaries/dictionary_library/dictionary_library.cpp
@@ -136,10 +136,7 @@ void * ClickHouseDictionary_v3_loadAll(void * data_ptr, ClickHouseLibrary::CStri
     return static_cast<void *>(&ptr->ctable);
 }
 
-void * ClickHouseDictionary_v3_loadKeys(void * data_ptr,
-    ClickHouseLibrary::CStrings * settings,
-    ClickHouseLibrary::CStrings * columns,
-    const ClickHouseLibrary::VectorUInt64 * requested_rows)
+void * ClickHouseDictionary_v3_loadKeys(void * data_ptr, ClickHouseLibrary::CStrings * settings, ClickHouseLibrary::Table * requested_keys)
 {
     auto ptr = static_cast<DataHolder *>(data_ptr);
     LOG(ptr->lib->log, "loadKeys lib call ptr=" << data_ptr << " => " << ptr);
@@ -151,20 +148,11 @@ void * ClickHouseDictionary_v3_loadKeys(void * data_ptr,
             LOG(ptr->lib->log, "setting " << i << " :" << settings->data[i]);
         }
     }
-    if (columns)
+    if (requested_keys)
     {
-        LOG(ptr->lib->log, "columns passed:" << columns->size);
-        for (size_t i = 0; i < columns->size; ++i)
-        {
-            LOG(ptr->lib->log, "col " << i << " :" << columns->data[i]);
-        }
-    }
-    if (requested_rows)
-    {
-        LOG(ptr->lib->log, "requested_rows passed: " << requested_rows->size);
-        for (size_t i = 0; i < requested_rows->size; ++i)
-        {
-            LOG(ptr->lib->log, "id " << i << " :" << requested_rows->data[i]);
+        LOG(ptr->lib->log, "requested_keys columns passed: " << requested_keys->size);
+        for (size_t i = 0; i < requested_keys->size; ++i) {
+            LOG(ptr->lib->log, "requested_keys at column " << i << " passed: " << requested_keys->data[i].size);
         }
     }
 
diff --git a/dbms/tests/external_dictionaries/dictionary_library/dictionary_library_c.c b/dbms/tests/external_dictionaries/dictionary_library/dictionary_library_c.c
index c3d5ba901d7..2a18b236485 100644
--- a/dbms/tests/external_dictionaries/dictionary_library/dictionary_library_c.c
+++ b/dbms/tests/external_dictionaries/dictionary_library/dictionary_library_c.c
@@ -30,6 +30,27 @@ typedef struct
     int someField;
 } DataHolder;
 
+typedef struct
+{
+    const void * data;
+    uint64_t size;
+} ClickHouseLibField;
+
+typedef struct
+{
+    const ClickHouseLibField * data;
+    uint64_t size;
+} ClickHouseLibRow;
+
+typedef struct
+{
+    const ClickHouseLibRow * data;
+    uint64_t size;
+    uint64_t error_code;
+    const char * error_string;
+} ClickHouseLibTable;
+
+
 #define LOG(logger, format, ...)                  \
     do                                            \
     {                                             \
@@ -54,11 +75,10 @@ void * ClickHouseDictionary_v3_loadAll(void * data_ptr, ClickHouseLibCStrings *
     return 0;
 }
 
-void * ClickHouseDictionary_v3_loadKeys(
-    void * data_ptr, ClickHouseLibCStrings * settings, ClickHouseLibCStrings * columns, const ClickHouseLibVectorUInt64 * requested_rows)
+void * ClickHouseDictionary_v3_loadKeys(void * data_ptr, ClickHouseLibCStrings * settings, ClickHouseLibTable* requested_keys)
 {
     LibHolder * lib = ((DataHolder *)(data_ptr))->lib;
-    LOG(lib->log, "loadKeys c lib call ptr=%p size=%" PRIu64, data_ptr, requested_rows->size);
+    LOG(lib->log, "loadKeys c lib call ptr=%p size=%" PRIu64, data_ptr, requested_keys->size);
     return 0;
 }