diff --git a/CMakeLists.txt b/CMakeLists.txt
index 276fc1ab..76b5f69b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -214,12 +214,11 @@ else()
 endif()
 
 set(BUILD_TESTS FALSE CACHE BOOL "Build Zano tests")
-set(DB_ENGINE "lmdb" CACHE STRING "Select database engine")
-if (DB_ENGINE STREQUAL "lmdb")
-  add_definitions(-DDB_ENGINE_LMDB)
-elseif(DB_ENGINE STREQUAL "mdbx")
-  add_definitions(-DDB_ENGINE_MDBX)
-endif() 
+set(DISABLE_MDBX FALSE CACHE BOOL "Exclude mdbx from build(need for a first time)") 
+if(NOT DISABLE_MDBX)
+   add_definitions(-DENABLED_ENGINE_MDBX)
+endif()
+
   
 add_subdirectory(contrib)
 add_subdirectory(src)
diff --git a/contrib/CMakeLists.txt b/contrib/CMakeLists.txt
index 36f7053c..657eabaf 100644
--- a/contrib/CMakeLists.txt
+++ b/contrib/CMakeLists.txt
@@ -7,9 +7,12 @@ add_subdirectory(db)
 add_subdirectory(ethereum)
 
 
-set_property(TARGET upnpc-static PROPERTY FOLDER "contrib/miniupnp")
+set_property(TARGET libminiupnpc-static PROPERTY FOLDER "contrib")
 set_property(TARGET zlibstatic PROPERTY FOLDER "contrib")
-set_property(TARGET ${DB_ENGINE} PROPERTY FOLDER "contrib")
+set_property(TARGET mdbx PROPERTY FOLDER "contrib")
+set_property(TARGET lmdb PROPERTY FOLDER "contrib")
+set_property(TARGET upnpc-static mdbx_chk mdbx_copy mdbx_dump mdbx_load mdbx_stat minigzip ntdll_extra_target zlib example PROPERTY FOLDER "unused")
+
 
 if(MSVC)
   set_property(TARGET upnpc-static APPEND_STRING PROPERTY COMPILE_FLAGS " /wd4244 /wd4267")
diff --git a/contrib/db/CMakeLists.txt b/contrib/db/CMakeLists.txt
index a0638716..9497760e 100644
--- a/contrib/db/CMakeLists.txt
+++ b/contrib/db/CMakeLists.txt
@@ -1,5 +1,4 @@
 
-if (DB_ENGINE STREQUAL "lmdb")
   message("DB ENGINE: lmdb")  
   add_subdirectory(liblmdb)
   if(MSVC)
@@ -8,8 +7,7 @@ if (DB_ENGINE STREQUAL "lmdb")
      # Warnings as used by LMDB itself (LMDB_0.9.23)
      target_compile_options(lmdb PRIVATE -Wall -Wno-unused-parameter -Wbad-function-cast -Wuninitialized)
   endif()
-elseif(DB_ENGINE STREQUAL "mdbx")
-  message("DB ENGINE: mdbx")  
-  add_subdirectory(libmdbx)
-endif()
-
+  if(NOT DISABLE_MDBX)
+     message("DB ENGINE: mdbx")  
+     add_subdirectory(libmdbx)
+  endif()
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 1bc8e4d0..ba358dd6 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -116,7 +116,7 @@ add_library(wallet ${WALLET})
 add_dependencies(wallet version ${PCH_LIB_NAME})
 ENABLE_SHARED_PCH(WALLET)
 
-target_link_libraries(currency_core ${DB_ENGINE})
+target_link_libraries(currency_core lmdb mdbx)
 
 add_executable(daemon ${DAEMON} ${P2P} ${CURRENCY_PROTOCOL})
 add_dependencies(daemon version)
diff --git a/src/common/command_line.cpp b/src/common/command_line.cpp
index e6fd1c44..e3407412 100644
--- a/src/common/command_line.cpp
+++ b/src/common/command_line.cpp
@@ -30,4 +30,5 @@ namespace command_line
   const arg_descriptor<bool>        arg_disable_stop_if_time_out_of_sync = { "disable-stop-if-time-out-of-sync", "Do not stop the daemon if serious time synchronization problem is detected", false, true };
   const arg_descriptor<bool>        arg_disable_stop_on_low_free_space   = { "disable-stop-on-low-free-space", "Do not stop the daemon if free space at data dir is critically low", false, true };
   const arg_descriptor<bool>        arg_enable_offers_service = { "enable-offers-service", "Enables marketplace feature", false, false};
+  const arg_descriptor<std::string> arg_db_engine =             { "db-engine", "Specify database engine for storage. May be \"lmdb\"(default) or \"mdbx\"", ARG_DB_ENGINE_LMDB, false };
 }
diff --git a/src/common/command_line.h b/src/common/command_line.h
index 65edaa39..eb849101 100644
--- a/src/common/command_line.h
+++ b/src/common/command_line.h
@@ -172,6 +172,9 @@ namespace command_line
     return get_arg<bool, false>(vm, arg);
   }
 
+#define ARG_DB_ENGINE_LMDB   "lmdb"
+#define ARG_DB_ENGINE_MDBX   "mdbx"
+
 
   extern const arg_descriptor<bool>        arg_help;
   extern const arg_descriptor<bool>        arg_version;
@@ -188,4 +191,5 @@ namespace command_line
   extern const arg_descriptor<bool>        arg_disable_stop_if_time_out_of_sync;
   extern const arg_descriptor<bool>        arg_disable_stop_on_low_free_space;
   extern const arg_descriptor<bool>        arg_enable_offers_service;
+  extern const arg_descriptor<std::string> arg_db_engine;
 }
diff --git a/src/common/db_abstract_accessor.h b/src/common/db_abstract_accessor.h
index 56e517cb..596c7bdd 100644
--- a/src/common/db_abstract_accessor.h
+++ b/src/common/db_abstract_accessor.h
@@ -95,7 +95,7 @@ namespace tools
       {
         close();
       }
-
+      void reset_backend(std::shared_ptr<i_db_backend> backend) { m_backend = backend; }
       performance_data& get_performance_data_for_handle(container_handle h) const  { return m_performance_data_map[h]; }
       performance_data& get_performance_data_global() const { return m_gperformance_data; }
 
diff --git a/src/common/db_backend_base.h b/src/common/db_backend_base.h
index 538abd62..c71ec2a2 100644
--- a/src/common/db_backend_base.h
+++ b/src/common/db_backend_base.h
@@ -45,6 +45,7 @@ namespace tools
       virtual bool clear(container_handle h) = 0;
       virtual bool enumerate(container_handle h, i_db_callback* pcb)=0;
       virtual bool get_stat_info(stat_info& si) = 0;
+      virtual const char* name()=0;
       virtual ~i_db_backend(){};
     };
   }
diff --git a/src/common/db_backend_lmdb.cpp b/src/common/db_backend_lmdb.cpp
index d0e5e560..b02a8fe7 100644
--- a/src/common/db_backend_lmdb.cpp
+++ b/src/common/db_backend_lmdb.cpp
@@ -3,8 +3,6 @@
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#ifdef DB_ENGINE_LMDB
-
 #include "db_backend_lmdb.h"
 #include "misc_language.h"
 #include "string_coding.h"
@@ -381,9 +379,12 @@ namespace tools
       }
       return true;
     }
+    const char* lmdb_db_backend::name()
+    {
+      return "lmdb";
+    }
   }
 }
 
 #undef LOG_DEFAULT_CHANNEL 
 #define LOG_DEFAULT_CHANNEL NULL
-#endif
\ No newline at end of file
diff --git a/src/common/db_backend_lmdb.h b/src/common/db_backend_lmdb.h
index 93effc98..ebe7cf4e 100644
--- a/src/common/db_backend_lmdb.h
+++ b/src/common/db_backend_lmdb.h
@@ -4,7 +4,6 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #pragma once
-#ifdef DB_ENGINE_LMDB
 
 #include  <thread>
 
@@ -55,6 +54,7 @@ namespace tools
       bool set(container_handle h, const char* k, size_t s, const char* v, size_t vs);
       bool enumerate(container_handle h, i_db_callback* pcb);
       bool get_stat_info(tools::db::stat_info& si);
+      const char* name();
       //-------------------------------------------------------------------------------------
       bool have_tx();
       MDB_txn* get_current_tx();
@@ -62,4 +62,3 @@ namespace tools
     };
   }
 }
-#endif
\ No newline at end of file
diff --git a/src/common/db_backend_mdbx.cpp b/src/common/db_backend_mdbx.cpp
index ebe80baa..9ee58ef8 100644
--- a/src/common/db_backend_mdbx.cpp
+++ b/src/common/db_backend_mdbx.cpp
@@ -2,9 +2,7 @@
 // Copyright (c) 2014-2018 The Louisdor Project 
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
-
-#ifdef DB_ENGINE_MDBX
-
+#ifdef ENABLED_ENGINE_MDBX
 #include "db_backend_mdbx.h"
 #include "misc_language.h"
 #include "string_coding.h"
@@ -392,10 +390,13 @@ namespace tools
       }
       return true;
     }
+    const char* mdbx_db_backend::name()
+    {
+      return "mdbx";
+    }
   }
 }
 
 #undef LOG_DEFAULT_CHANNEL 
 #define LOG_DEFAULT_CHANNEL NULL
-
 #endif
\ No newline at end of file
diff --git a/src/common/db_backend_mdbx.h b/src/common/db_backend_mdbx.h
index f2b603ae..443cbe5a 100644
--- a/src/common/db_backend_mdbx.h
+++ b/src/common/db_backend_mdbx.h
@@ -4,9 +4,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #pragma once
-
-#ifdef DB_ENGINE_MDBX
-
+#ifdef ENABLED_ENGINE_MDBX
 #include  <thread>
 
 #include "include_base_utils.h"
@@ -56,6 +54,7 @@ namespace tools
       bool set(container_handle h, const char* k, size_t s, const char* v, size_t vs);
       bool enumerate(container_handle h, i_db_callback* pcb);
       bool get_stat_info(tools::db::stat_info& si);
+      const char* name();
       //-------------------------------------------------------------------------------------
       bool have_tx();
       MDBX_txn* get_current_tx();
@@ -64,5 +63,4 @@ namespace tools
     
   }
 }
-
 #endif
\ No newline at end of file
diff --git a/src/common/db_backend_selector.h b/src/common/db_backend_selector.h
index e2f37bb0..afaee01a 100644
--- a/src/common/db_backend_selector.h
+++ b/src/common/db_backend_selector.h
@@ -7,15 +7,35 @@
 
 #include "db_backend_lmdb.h"
 #include "db_backend_mdbx.h"
+#include "common/command_line.h"
+#include "common/db_abstract_accessor.h"
 
 namespace tools
 {
   namespace db
   {
-#ifdef DB_ENGINE_LMDB
-    typedef lmdb_db_backend default_db_backend;
-#elif DB_ENGINE_MDBX
-    typedef mdbx_db_backend default_db_backend;
-#endif
+    inline
+      bool select_db_engine_from_arg(const boost::program_options::variables_map& vm, tools::db::basic_db_accessor& rdb)
+    {
+      if (command_line::get_arg(vm, command_line::arg_db_engine) == ARG_DB_ENGINE_LMDB)
+      {
+        rdb.reset_backend(std::shared_ptr<tools::db::i_db_backend>(new tools::db::lmdb_db_backend));
+      }
+      else if (command_line::get_arg(vm, command_line::arg_db_engine) == ARG_DB_ENGINE_MDBX)
+      {
+#ifdef ENABLED_ENGINE_MDBX
+        rdb.reset_backend(std::shared_ptr<tools::db::i_db_backend>(new tools::db::mdbx_db_backend));
+#else
+        LOG_PRINT_L0(" DB ENGINE: " << ARG_DB_ENGINE_MDBX << " is not suported by this build(see DISABLE_MDBX cmake option), STOPPING");
+        return false;
+#endif 
+      }
+      else
+      {
+        LOG_PRINT_RED_L0(" UNKNOWN DB ENGINE: " << command_line::get_arg(vm, command_line::arg_db_engine) << ", STOPPING");
+        return false;
+      }
+      return true;
+    }
   }
 }
\ No newline at end of file
diff --git a/src/currency_core/blockchain_storage.cpp b/src/currency_core/blockchain_storage.cpp
index 52dc0320..a823d278 100644
--- a/src/currency_core/blockchain_storage.cpp
+++ b/src/currency_core/blockchain_storage.cpp
@@ -69,7 +69,7 @@ using namespace currency;
 #endif
 #define BLOCK_POS_STRICT_SEQUENCE_LIMIT                               20
 
-
+#define CURRENCY_BLOCKCHAINDATA_FOLDERNAME_SUFFIX                     "_v1"
 
 DISABLE_VS_WARNINGS(4267)
 
@@ -80,7 +80,7 @@ namespace
 }
 
 //------------------------------------------------------------------
-blockchain_storage::blockchain_storage(tx_memory_pool& tx_pool) :m_db(std::shared_ptr<tools::db::i_db_backend>(new tools::db::default_db_backend), m_rw_lock),
+blockchain_storage::blockchain_storage(tx_memory_pool& tx_pool) :m_db(nullptr, m_rw_lock),
                                                                  m_db_blocks(m_db),
                                                                  m_db_blocks_index(m_db),
                                                                  m_db_transactions(m_db),
@@ -206,7 +206,13 @@ bool blockchain_storage::validate_instance(const std::string& path)
 bool blockchain_storage::init(const std::string& config_folder, const boost::program_options::variables_map& vm)
 {
 //  CRITICAL_REGION_LOCAL(m_read_lock);
-
+  if (!select_db_engine_from_arg(vm, m_db))
+  {
+    LOG_PRINT_RED_L0("Failed to select db engine");
+    return false;
+  }
+  LOG_PRINT_L0("DB ENGINE USED BY CORE: " << m_db.get_backend()->name());
+  
   if (!validate_instance(config_folder))
   {
     LOG_ERROR("Failed to initialize instance");
@@ -229,8 +235,8 @@ bool blockchain_storage::init(const std::string& config_folder, const boost::pro
     LOG_PRINT_YELLOW("Removing old DB in " << old_db_folder_path << "...", LOG_LEVEL_0);
     boost::filesystem::remove_all(epee::string_encoding::utf8_to_wstring(old_db_folder_path));
   }
-
-  const std::string db_folder_path = m_config_folder + "/" CURRENCY_BLOCKCHAINDATA_FOLDERNAME;
+  ;
+  const std::string db_folder_path = m_config_folder + ("/" CURRENCY_BLOCKCHAINDATA_FOLDERNAME_PREFIX) + m_db.get_backend()->name() + CURRENCY_BLOCKCHAINDATA_FOLDERNAME_SUFFIX;
   LOG_PRINT_L0("Loading blockchain from " << db_folder_path);
 
   bool db_opened_okay = false;
diff --git a/src/currency_core/currency_config.h b/src/currency_core/currency_config.h
index b3f1f6cf..c6b210cd 100644
--- a/src/currency_core/currency_config.h
+++ b/src/currency_core/currency_config.h
@@ -190,14 +190,9 @@
 #define CURRENCY_POOLDATA_FOLDERNAME_OLD                "poolstate"
 #define CURRENCY_BLOCKCHAINDATA_FOLDERNAME_OLD          "blockchain"
 
-#ifdef DB_ENGINE_LMDB
-  #define CURRENCY_BLOCKCHAINDATA_DB_ENGINE_NAME          "lmdb"
-#elif DB_ENGINE_MDBX
-  #define CURRENCY_BLOCKCHAINDATA_DB_ENGINE_NAME          "mdbx"
-#endif
 
-#define CURRENCY_POOLDATA_FOLDERNAME                    "poolstate_" CURRENCY_BLOCKCHAINDATA_DB_ENGINE_NAME "_v1"
-#define CURRENCY_BLOCKCHAINDATA_FOLDERNAME              "blockchain_" CURRENCY_BLOCKCHAINDATA_DB_ENGINE_NAME "_v1"
+#define CURRENCY_POOLDATA_FOLDERNAME_PREFIX                    "poolstate_"
+#define CURRENCY_BLOCKCHAINDATA_FOLDERNAME_PREFIX              "blockchain_" 
 
 #define P2P_NET_DATA_FILENAME                           "p2pstate.bin"
 #define MINER_CONFIG_FILENAME                           "miner_conf.json"
diff --git a/src/currency_core/currency_core.cpp b/src/currency_core/currency_core.cpp
index a79dfb2a..20e81fed 100644
--- a/src/currency_core/currency_core.cpp
+++ b/src/currency_core/currency_core.cpp
@@ -142,7 +142,7 @@ namespace currency
     uint64_t available_space = 0;
     CHECK_AND_ASSERT_MES(!check_if_free_space_critically_low(&available_space), false, "free space in data folder is critically low: " << std::fixed << available_space / (1024 * 1024) << " MB");
 
-    r = m_mempool.init(m_config_folder);
+    r = m_mempool.init(m_config_folder, vm);
     CHECK_AND_ASSERT_MES(r, false, "Failed to initialize memory pool");
 
     r = m_blockchain_storage.init(m_config_folder, vm);
diff --git a/src/currency_core/tx_pool.cpp b/src/currency_core/tx_pool.cpp
index d5e4e02d..3c29a609 100644
--- a/src/currency_core/tx_pool.cpp
+++ b/src/currency_core/tx_pool.cpp
@@ -32,6 +32,8 @@ DISABLE_VS_WARNINGS(4244 4345 4503) //'boost::foreach_detail_::or_' : decorated
 #define TRANSACTION_POOL_OPTIONS_ID_STORAGE_MAJOR_COMPATIBILITY_VERSION 92 // DON'T CHANGE THIS, if you need to resync db! Change TRANSACTION_POOL_MAJOR_COMPATIBILITY_VERSION instead!
 #define TRANSACTION_POOL_MAJOR_COMPATIBILITY_VERSION      BLOCKCHAIN_STORAGE_MAJOR_COMPATIBILITY_VERSION + 1
 
+#define CURRENCY_POOLDATA_FOLDERNAME_SUFFIX               "_v1"
+
 #undef LOG_DEFAULT_CHANNEL 
 #define LOG_DEFAULT_CHANNEL "tx_pool"
 ENABLE_CHANNEL_BY_DEFAULT("tx_pool");
@@ -42,7 +44,7 @@ namespace currency
   tx_memory_pool::tx_memory_pool(blockchain_storage& bchs, i_currency_protocol* pprotocol) :
     m_blockchain(bchs),
     m_pprotocol(pprotocol),
-    m_db(std::shared_ptr<tools::db::i_db_backend>(new tools::db::default_db_backend), m_dummy_rw_lock),
+    m_db(nullptr, m_dummy_rw_lock),
     m_db_transactions(m_db),
     m_db_black_tx_list(m_db),
     m_db_solo_options(m_db), 
@@ -1116,8 +1118,15 @@ namespace currency
     m_db.commit_transaction();
   }
   //---------------------------------------------------------------------------------
-  bool tx_memory_pool::init(const std::string& config_folder)
+  bool tx_memory_pool::init(const std::string& config_folder, const boost::program_options::variables_map& vm)
   {
+    if (!select_db_engine_from_arg(vm, m_db))
+    {
+      LOG_PRINT_RED_L0("Failed to select db engine");
+      return false;
+    }
+    LOG_PRINT_L0("DB ENGINE USED BY POOL: " << m_db.get_backend()->name());
+
     m_config_folder = config_folder;
 
     uint64_t cache_size_l1 = CACHE_SIZE;
@@ -1131,7 +1140,8 @@ namespace currency
       boost::filesystem::remove_all(epee::string_encoding::utf8_to_wstring(old_db_folder_path));
     }
 
-    const std::string db_folder_path = m_config_folder + "/" CURRENCY_POOLDATA_FOLDERNAME;
+    const std::string db_folder_path = m_config_folder + ("/" CURRENCY_POOLDATA_FOLDERNAME_PREFIX) + m_db.get_backend()->name() + CURRENCY_POOLDATA_FOLDERNAME_SUFFIX;
+    
     LOG_PRINT_L0("Loading blockchain from " << db_folder_path << "...");
 
     bool db_opened_okay = false;
diff --git a/src/currency_core/tx_pool.h b/src/currency_core/tx_pool.h
index d546a4a8..6d9bad9d 100644
--- a/src/currency_core/tx_pool.h
+++ b/src/currency_core/tx_pool.h
@@ -20,6 +20,7 @@ using namespace epee;
 #include "math_helper.h"
 
 #include "common/db_abstract_accessor.h"
+#include "common/command_line.h"
 
 #include "currency_format_utils.h"
 #include "verification_context.h"
@@ -114,7 +115,7 @@ namespace currency
     void clear();
 
     // load/store operations
-    bool init(const std::string& config_folder);
+    bool init(const std::string& config_folder, const boost::program_options::variables_map& vm);
     bool deinit();
     bool fill_block_template(block &bl, bool pos, size_t median_size, const boost::multiprecision::uint128_t& already_generated_coins, size_t &total_size, uint64_t &fee, uint64_t height);
     bool get_transactions(std::list<transaction>& txs) const;
diff --git a/src/daemon/daemon.cpp b/src/daemon/daemon.cpp
index f81d1a5a..c168ad63 100644
--- a/src/daemon/daemon.cpp
+++ b/src/daemon/daemon.cpp
@@ -147,6 +147,7 @@ int main(int argc, char* argv[])
   command_line::add_arg(desc_cmd_sett, command_line::arg_disable_stop_if_time_out_of_sync);
   command_line::add_arg(desc_cmd_sett, command_line::arg_disable_stop_on_low_free_space);
   command_line::add_arg(desc_cmd_sett, command_line::arg_enable_offers_service);
+  command_line::add_arg(desc_cmd_sett, command_line::arg_db_engine);  
 
 
   arg_market_disable.default_value = true;
diff --git a/src/gui/qt-daemon/application/daemon_backend.cpp b/src/gui/qt-daemon/application/daemon_backend.cpp
index dab77d8b..36ac093e 100644
--- a/src/gui/qt-daemon/application/daemon_backend.cpp
+++ b/src/gui/qt-daemon/application/daemon_backend.cpp
@@ -120,6 +120,7 @@ bool daemon_backend::init(int argc, char* argv[], view::i_view* pview_handler)
   command_line::add_arg(desc_cmd_sett, command_line::arg_log_level);
   command_line::add_arg(desc_cmd_sett, command_line::arg_console);
   command_line::add_arg(desc_cmd_sett, command_line::arg_show_details);
+  command_line::add_arg(desc_cmd_sett, command_line::arg_db_engine);
   command_line::add_arg(desc_cmd_sett, arg_alloc_win_console);
   command_line::add_arg(desc_cmd_sett, arg_html_folder);
   command_line::add_arg(desc_cmd_sett, arg_xcode_stub);