diff --git a/include/pika_admin.h b/include/pika_admin.h
index 1741ba8488..06411a1524 100644
--- a/include/pika_admin.h
+++ b/include/pika_admin.h
@@ -102,7 +102,11 @@ class CompactCmd : public Cmd {
   virtual void Do();
 
  private:
+  std::string struct_type_;
   virtual void DoInitial(PikaCmdArgsType &argvs, const CmdInfo* const ptr_info);
+  virtual void Clear() {
+    struct_type_.clear();
+  }
 };
 
 class PurgelogstoCmd : public Cmd {
@@ -142,6 +146,19 @@ class FlushallCmd : public Cmd {
   virtual void DoInitial(PikaCmdArgsType &argvs, const CmdInfo* const ptr_info);
 };
 
+class FlushdbCmd : public Cmd {
+ public:
+  FlushdbCmd() {}
+  virtual void Do();
+
+ private:
+  std::string db_name_;
+  virtual void DoInitial(PikaCmdArgsType &argvs, const CmdInfo* const ptr_info);
+  virtual void Clear() {
+    db_name_.clear();
+  }
+};
+
 class ReadonlyCmd : public Cmd {
  public:
   ReadonlyCmd() : is_open_(false) {}
diff --git a/include/pika_command.h b/include/pika_command.h
index a30290ba8d..37ff86e76f 100644
--- a/include/pika_command.h
+++ b/include/pika_command.h
@@ -29,6 +29,7 @@ const std::string kCmdNamePurgelogsto = "purgelogsto";
 const std::string kCmdNamePing = "ping";
 const std::string kCmdNameSelect = "select";
 const std::string kCmdNameFlushall = "flushall";
+const std::string kCmdNameFlushdb = "flushdb";
 const std::string kCmdNameReadonly = "readonly";
 const std::string kCmdNameClient = "client";
 const std::string kCmdNameShutdown = "shutdown";
@@ -297,6 +298,7 @@ class CmdRes {
     kInvalidParameter,
     kWrongNum,
     kInvalidIndex,
+    kInvalidDbType,
     kErrOther,
   };
 
@@ -361,6 +363,9 @@ class CmdRes {
     case kInvalidIndex:
       result = "-ERR invalid DB index\r\n";
       break;
+    case kInvalidDbType:
+      result = "-ERR invalid DB type\r\n";
+      break;
     case kErrOther:
       result = "-ERR ";
       result.append(message_);
diff --git a/include/pika_server.h b/include/pika_server.h
index 439d27fa55..ca076f84de 100644
--- a/include/pika_server.h
+++ b/include/pika_server.h
@@ -174,6 +174,11 @@ class PikaServer {
    */
   bool ServerInit();
 
+  /*
+   * Nemo options init
+   */
+  void NemoOptionInit(nemo::Options* option);
+
   /*
    * Binlog
    */
@@ -358,8 +363,9 @@ class PikaServer {
   }
   slash::Mutex & GetSlavesMutex() { return db_sync_protector_; }
 
-  //flushall
+  //flushall & flushdb
   bool FlushAll();
+  bool FlushDb(const std::string& db_name);
   void PurgeDir(std::string& path);
 
   /*
diff --git a/src/pika_admin.cc b/src/pika_admin.cc
index ec6c4ae9b9..68cc8e0767 100644
--- a/src/pika_admin.cc
+++ b/src/pika_admin.cc
@@ -307,14 +307,35 @@ void BgsaveoffCmd::Do() {
 }
 
 void CompactCmd::DoInitial(PikaCmdArgsType &argv, const CmdInfo* const ptr_info) {
-  if (!ptr_info->CheckArg(argv.size())) {
+  if (!ptr_info->CheckArg(argv.size())
+    || argv.size() > 2) {
     res_.SetRes(CmdRes::kWrongNum, kCmdNameCompact);
     return;
   }
+
+  if (argv.size() == 2) {
+    struct_type_ = slash::StringToLower(argv[1]);
+  }
 }
 
 void CompactCmd::Do() {
-  nemo::Status s = g_pika_server->db()->Compact(nemo::kALL);
+  nemo::Status s;
+  if (struct_type_.empty()) {
+    s = g_pika_server->db()->Compact(nemo::kALL);
+  } else if (struct_type_ == "string") {
+    s = g_pika_server->db()->Compact(nemo::kKV_DB);
+  } else if (struct_type_ == "hash") {
+    s = g_pika_server->db()->Compact(nemo::kHASH_DB);
+  } else if (struct_type_ == "set") {
+    s = g_pika_server->db()->Compact(nemo::kSET_DB);
+  } else if (struct_type_ == "zset") {
+    s = g_pika_server->db()->Compact(nemo::kZSET_DB);
+  } else if (struct_type_ == "list") {
+    s = g_pika_server->db()->Compact(nemo::kLIST_DB);
+  } else {
+    res_.SetRes(CmdRes::kInvalidDbType);
+    return;
+  }
   if (s.ok()) {
     res_.SetRes(CmdRes::kOk);
   } else {
@@ -391,6 +412,37 @@ void FlushallCmd::Do() {
   g_pika_server->RWUnlock();
 }
 
+void FlushdbCmd::DoInitial(PikaCmdArgsType &argv, const CmdInfo* const ptr_info) {
+  if (!ptr_info->CheckArg(argv.size())) {
+    res_.SetRes(CmdRes::kWrongNum, kCmdNameFlushdb);
+    return;
+  }
+  std::string struct_type = slash::StringToLower(argv[1]);
+  if (struct_type == "string") {
+    db_name_ = "kv";
+  } else if (struct_type == "hash") {
+    db_name_ = "hash";
+  } else if (struct_type == "set") {
+    db_name_ = "set";
+  } else if (struct_type == "zset") {
+    db_name_ = "zset";
+  } else if (struct_type == "list") {
+    db_name_ = "list";
+  } else {
+    res_.SetRes(CmdRes::kInvalidDbType);
+  }
+}
+
+void FlushdbCmd::Do() {
+  g_pika_server->RWLockWriter();
+  if (g_pika_server->FlushDb(db_name_)) {
+    res_.SetRes(CmdRes::kOk);
+  } else {
+    res_.SetRes(CmdRes::kErrOther, "There are some bgthread using db now, can not flushdb");
+  }
+  g_pika_server->RWUnlock();
+}
+
 void ReadonlyCmd::DoInitial(PikaCmdArgsType &argv, const CmdInfo* const ptr_info) {
   if (!ptr_info->CheckArg(argv.size())) {
     res_.SetRes(CmdRes::kWrongNum, kCmdNameReadonly);
diff --git a/src/pika_command.cc b/src/pika_command.cc
index 945ce6b5ad..42747402a8 100644
--- a/src/pika_command.cc
+++ b/src/pika_command.cc
@@ -35,7 +35,7 @@ void InitCmdInfoTable() {
   cmd_infos.insert(std::pair<std::string, CmdInfo*>(kCmdNameBgsave, bgsaveptr));
   CmdInfo* bgsaveoffptr = new CmdInfo(kCmdNameBgsaveoff, 1, kCmdFlagsRead | kCmdFlagsAdmin);
   cmd_infos.insert(std::pair<std::string, CmdInfo*>(kCmdNameBgsaveoff, bgsaveoffptr));
-  CmdInfo* compactptr = new CmdInfo(kCmdNameCompact, 1, kCmdFlagsRead | kCmdFlagsAdmin);
+  CmdInfo* compactptr = new CmdInfo(kCmdNameCompact, -1, kCmdFlagsRead | kCmdFlagsAdmin);
   cmd_infos.insert(std::pair<std::string, CmdInfo*>(kCmdNameCompact, compactptr));
   CmdInfo* purgelogptr = new CmdInfo(kCmdNamePurgelogsto, 2, kCmdFlagsRead | kCmdFlagsAdmin);
   cmd_infos.insert(std::pair<std::string, CmdInfo*>(kCmdNamePurgelogsto, purgelogptr));
@@ -45,6 +45,8 @@ void InitCmdInfoTable() {
   cmd_infos.insert(std::pair<std::string, CmdInfo*>(kCmdNameSelect, selectptr));
   CmdInfo* flushallptr = new CmdInfo(kCmdNameFlushall, 1, kCmdFlagsWrite | kCmdFlagsSuspend | kCmdFlagsAdmin);
   cmd_infos.insert(std::pair<std::string, CmdInfo*>(kCmdNameFlushall, flushallptr));
+  CmdInfo* flushdbptr = new CmdInfo(kCmdNameFlushdb, 2, kCmdFlagsWrite | kCmdFlagsSuspend | kCmdFlagsAdmin);
+  cmd_infos.insert(std::pair<std::string, CmdInfo*>(kCmdNameFlushdb, flushdbptr));
   CmdInfo* readonlyptr = new CmdInfo(kCmdNameReadonly, 2, kCmdFlagsRead | kCmdFlagsSuspend | kCmdFlagsAdmin);
   cmd_infos.insert(std::pair<std::string, CmdInfo*>(kCmdNameReadonly, readonlyptr));
   CmdInfo* clientptr = new CmdInfo(kCmdNameClient, -2, kCmdFlagsRead | kCmdFlagsAdmin);
@@ -496,6 +498,8 @@ void InitCmdTable(std::unordered_map<std::string, Cmd*> *cmd_table) {
   cmd_table->insert(std::pair<std::string, Cmd*>(kCmdNameSelect, selectptr));
   Cmd* flushallptr = new FlushallCmd();
   cmd_table->insert(std::pair<std::string, Cmd*>(kCmdNameFlushall, flushallptr));
+  Cmd* flushdbptr = new FlushdbCmd();
+  cmd_table->insert(std::pair<std::string, Cmd*>(kCmdNameFlushdb, flushdbptr));
   Cmd* readonlyptr = new ReadonlyCmd();
   cmd_table->insert(std::pair<std::string, Cmd*>(kCmdNameReadonly, readonlyptr));
   Cmd* clientptr = new ClientCmd();
diff --git a/src/pika_server.cc b/src/pika_server.cc
index 786b5b33bf..cbe36293c4 100644
--- a/src/pika_server.cc
+++ b/src/pika_server.cc
@@ -60,20 +60,7 @@ PikaServer::PikaServer() :
   }
   // Create nemo handle
   nemo::Options option;
-
-  option.write_buffer_size = g_pika_conf->write_buffer_size();
-  option.target_file_size_base = g_pika_conf->target_file_size_base();
-  option.max_background_flushes = g_pika_conf->max_background_flushes();
-  option.max_background_compactions = g_pika_conf->max_background_compactions();
-  option.max_open_files = g_pika_conf->max_cache_files();
-  option.max_bytes_for_level_multiplier = g_pika_conf->max_bytes_for_level_multiplier();
-	if (g_pika_conf->compression() == "none") {
-    option.compression = nemo::Options::CompressionType::kNoCompression;
-  } else if (g_pika_conf->compression() == "snappy") {
-    option.compression = nemo::Options::CompressionType::kSnappyCompression;
-  } else if (g_pika_conf->compression() == "zlib") {
-    option.compression = nemo::Options::CompressionType::kZlibCompression;
-  }
+  NemoOptionInit(&option);
 
   std::string db_path = g_pika_conf->db_path();
   LOG(INFO) << "Prepare DB...";
@@ -246,6 +233,22 @@ bool PikaServer::ServerInit() {
 
 }
 
+void PikaServer::NemoOptionInit(nemo::Options* option) {
+  option->write_buffer_size = g_pika_conf->write_buffer_size();
+  option->target_file_size_base = g_pika_conf->target_file_size_base();
+  option->max_background_flushes = g_pika_conf->max_background_flushes();
+  option->max_background_compactions = g_pika_conf->max_background_compactions();
+  option->max_open_files = g_pika_conf->max_cache_files();
+  option->max_bytes_for_level_multiplier = g_pika_conf->max_bytes_for_level_multiplier();
+  if (g_pika_conf->compression() == "none") {
+    option->compression = nemo::Options::CompressionType::kNoCompression;
+  } else if (g_pika_conf->compression() == "snappy") {
+    option->compression = nemo::Options::CompressionType::kSnappyCompression;
+  } else if (g_pika_conf->compression() == "zlib") {
+    option->compression = nemo::Options::CompressionType::kZlibCompression;
+  }
+}
+
 void PikaServer::Start() {
   int ret = 0;
   ret = pika_dispatch_thread_->StartThread();
@@ -1471,6 +1474,10 @@ bool PikaServer::FlushAll() {
       return false;
     }
   }
+
+  LOG(INFO) << "Delete old db...";
+  db_.reset();
+
   std::string dbpath = g_pika_conf->db_path();
   if (dbpath[dbpath.length() - 1] == '/') {
     dbpath.erase(dbpath.length() - 1);
@@ -1480,23 +1487,8 @@ bool PikaServer::FlushAll() {
   dbpath.append("/deleting");
   slash::RenameFile(g_pika_conf->db_path(), dbpath.c_str());
 
-  LOG(INFO) << "Delete old db...";
-  db_.reset();
-
   nemo::Options option;
-  option.write_buffer_size = g_pika_conf->write_buffer_size();
-  option.target_file_size_base = g_pika_conf->target_file_size_base();
-  option.max_background_flushes = g_pika_conf->max_background_flushes();
-  option.max_background_compactions = g_pika_conf->max_background_compactions();
-  option.max_open_files = g_pika_conf->max_cache_files();
-  option.max_bytes_for_level_multiplier = g_pika_conf->max_bytes_for_level_multiplier();
-  if (g_pika_conf->compression() == "none") {
-    option.compression = nemo::Options::CompressionType::kNoCompression;
-  } else if (g_pika_conf->compression() == "snappy") {
-    option.compression = nemo::Options::CompressionType::kSnappyCompression;
-  } else if (g_pika_conf->compression() == "zlib") {
-    option.compression = nemo::Options::CompressionType::kZlibCompression;
-  }
+  NemoOptionInit(&option);
 
   LOG(INFO) << "Prepare open new db...";
   db_ = std::shared_ptr<nemo::Nemo>(new nemo::Nemo(g_pika_conf->db_path(), option));
@@ -1505,6 +1497,42 @@ bool PikaServer::FlushAll() {
   return true;
 }
 
+bool PikaServer::FlushDb(const std::string& db_name) {
+  {
+    slash::MutexLock l(&bgsave_protector_);
+    if (bgsave_info_.bgsaving) {
+      return false;
+    }
+  }
+  {
+    slash::MutexLock l(&key_scan_protector_);
+    if (key_scan_info_.key_scaning_) {
+      return false;
+    }
+  }
+
+  std::string db_alias = db_name != "kv" ? db_name : "string";
+  LOG(INFO) << "Delete old " + db_alias + " db...";
+  db_.reset();
+
+  std::string dbpath = g_pika_conf->db_path();
+  if (dbpath[dbpath.length() - 1] != '/') {
+     dbpath.append("/");
+  }
+  std::string sub_dbpath = dbpath + db_name;
+  std::string del_dbpath = dbpath + db_alias + "_deleting";
+  slash::RenameFile(sub_dbpath, del_dbpath);
+
+  nemo::Options option;
+  NemoOptionInit(&option);
+
+  LOG(INFO) << "Prepare open new " + db_alias + " db...";
+  db_ = std::shared_ptr<nemo::Nemo>(new nemo::Nemo(g_pika_conf->db_path(), option));
+  LOG(INFO) << "open new " + db_alias + " db success";
+  PurgeDir(del_dbpath);
+  return true;
+}
+
 void PikaServer::PurgeDir(std::string& path) {
   std::string *dir_path = new std::string(path);
   // Start new thread if needed