diff --git a/benchmarks/db_bench_FieldDB.cc b/benchmarks/db_bench_FieldDB.cc
index 4238ef6..c7029aa 100644
--- a/benchmarks/db_bench_FieldDB.cc
+++ b/benchmarks/db_bench_FieldDB.cc
@@ -63,7 +63,6 @@ static const char* FLAGS_benchmarks =
     "readreverse,"
     "fill100K,"
     "crc32c,"
-    "readwhilewriting,"
     "CreateIndex,"
     "FindKeysByField,"
     "QueryByIndex,"
@@ -78,11 +77,7 @@ static const char* FLAGS_benchmarks =
     "ReadSeqWhileCreating,"
     "ReadSeqWhileDeleting,"
     "ReadRandomWhileCreating,"
-    "ReadRandomWhileDeleting,"
-    "snappycomp,"
-    "snappyuncomp,"
-    "zstdcomp,"
-    "zstduncomp,";
+    "ReadRandomWhileDeleting,";
 
 // Number of key/values to place in database
 static int FLAGS_num = 1000000;
@@ -1155,17 +1150,7 @@ class Benchmark {
           std::fprintf(stderr, "index status error in WriteWhileCreating\n");
           std::exit(1);
       }      
-
-      while (true) {
-        if (db_->GetIndexStatus("age") == IndexStatus::Exist) {
-          break;
-        }
-
-        db_->CreateIndexOnField("age", write_options_);
-      }
-
-      // Do not count any of the preceding work/delay in stats.
-      thread->stats.Start();
+      db_->CreateIndexOnField("age", write_options_);
     }
   }
 
@@ -1178,17 +1163,7 @@ class Benchmark {
           std::fprintf(stderr, "index status error in WriteWhileDeleting\n");
           std::exit(1);
       }      
-
-      while (true) {
-        if (db_->GetIndexStatus("age") == IndexStatus::NotExist) {
-          break;
-        }
-
-        db_->DeleteIndex("age", write_options_);
-      }
-
-      // Do not count any of the preceding work/delay in stats.
-      thread->stats.Start();
+      db_->DeleteIndex("age", write_options_);
     }
   }
 
@@ -1201,17 +1176,7 @@ class Benchmark {
           std::fprintf(stderr, "index status error in WriteWhileCreating\n");
           std::exit(1);
       }      
-
-      while (true) {
-        if (db_->GetIndexStatus("age") == IndexStatus::Exist) {
-          break;
-        }
-
-        db_->CreateIndexOnField("age", write_options_);
-      }
-
-      // Do not count any of the preceding work/delay in stats.
-      thread->stats.Start();
+      db_->CreateIndexOnField("age", write_options_);
     }
   }
 
@@ -1224,109 +1189,129 @@ class Benchmark {
           std::fprintf(stderr, "index status error in WriteWhileDeleting\n");
           std::exit(1);
       }      
-
-      while (true) {
-        if (db_->GetIndexStatus("age") == IndexStatus::NotExist) {
-          break;
-        }
-
-        db_->DeleteIndex("age", write_options_);
-      }
-
-      // Do not count any of the preceding work/delay in stats.
-      thread->stats.Start();
+      db_->DeleteIndex("age", write_options_);
     }
   }
 
   void ReadSeqWhileCreating(ThreadState* thread) {
     if (thread->tid > 0) {
-      ReadSequential(thread);
+        Iterator* iter = db_->NewIterator(ReadOptions());
+        iter->SeekToFirst();
+        int64_t bytes = 0;              
+        while (true) {
+        {
+          MutexLock l(&thread->shared->mu);
+          if (thread->shared->num_done == 1) {
+            // 创删索引完成
+            delete iter;
+            thread->stats.AddBytes(bytes);            
+            break;
+          }
+        }
+          bytes += iter->key().size() + iter->value().size();
+          thread->stats.FinishedSingleOp();
+          iter->Next();        
+          if (!iter->Valid())   iter->SeekToFirst();
+        }
     } else {
       // Special thread that keeps creating index until other threads are done.
       if (db_->GetIndexStatus("age") != IndexStatus::NotExist) {
           std::fprintf(stderr, "index status error in WriteWhileCreating\n");
           std::exit(1);
       }      
-
-      while (true) {
-        if (db_->GetIndexStatus("age") == IndexStatus::Exist) {
-          break;
-        }
-
-        db_->CreateIndexOnField("age", write_options_);
-      }
-
-      // Do not count any of the preceding work/delay in stats.
-      thread->stats.Start();
+      db_->CreateIndexOnField("age", write_options_);
     }
   }
 
   void ReadSeqWhileDeleting(ThreadState* thread) {
     if (thread->tid > 0) {
-      ReadSequential(thread);
+        Iterator* iter = db_->NewIterator(ReadOptions());
+        iter->SeekToFirst();
+        int64_t bytes = 0;              
+        while (true) {
+        {
+          MutexLock l(&thread->shared->mu);
+          if (thread->shared->num_done == 1) {
+            // 创删索引完成
+            delete iter;
+            thread->stats.AddBytes(bytes);            
+            break;
+          }
+        }
+          bytes += iter->key().size() + iter->value().size();
+          thread->stats.FinishedSingleOp();
+          iter->Next();        
+          if (!iter->Valid())   iter->SeekToFirst();
+        }
     } else {
       // Special thread that keeps creating index until other threads are done.
       if (db_->GetIndexStatus("age") != IndexStatus::Exist) {
           std::fprintf(stderr, "index status error in WriteWhileDeleting\n");
           std::exit(1);
       }      
-
-      while (true) {
-        if (db_->GetIndexStatus("age") == IndexStatus::NotExist) {
-          break;
-        }
-
-        db_->DeleteIndex("age", write_options_);
-      }
-
-      // Do not count any of the preceding work/delay in stats.
-      thread->stats.Start();
+      db_->DeleteIndex("age", write_options_);
     }
   }
 
   void ReadRandomWhileCreating(ThreadState* thread) {
     if (thread->tid > 0) {
-      ReadRandom(thread);
+          ReadOptions options;
+          int found = 0;
+          KeyBuffer key;
+          while (true) {
+          {
+            MutexLock l(&thread->shared->mu);
+            if (thread->shared->num_done == 1) {
+              // 创删索引完成
+              break;
+            }
+          }
+            const int k = thread->rand.Uniform(FLAGS_num);
+            key.Set(k);
+            FieldArray fields_ret;
+            if (db_->GetFields(options, key.slice(), &fields_ret).ok()) {
+              found++;
+            }
+            thread->stats.FinishedSingleOp();
+        }
     } else {
       // Special thread that keeps creating index until other threads are done.
       if (db_->GetIndexStatus("age") != IndexStatus::NotExist) {
           std::fprintf(stderr, "index status error in WriteWhileCreating\n");
           std::exit(1);
       }      
-
-      while (true) {
-        if (db_->GetIndexStatus("age") == IndexStatus::Exist) {
-          break;
-        }
-
-        db_->CreateIndexOnField("age", write_options_);
-      }
-
-      // Do not count any of the preceding work/delay in stats.
-      thread->stats.Start();
+      db_->CreateIndexOnField("age", write_options_);
     }
   }
 
   void ReadRandomWhileDeleting(ThreadState* thread) {
     if (thread->tid > 0) {
-      ReadRandom(thread);
+      ReadOptions options;
+      int found = 0;
+      KeyBuffer key;
+      while (true) {
+      {
+        MutexLock l(&thread->shared->mu);
+        if (thread->shared->num_done == 1) {
+          // 创删索引完成
+          break;
+        }
+      }
+        const int k = thread->rand.Uniform(FLAGS_num);
+        key.Set(k);
+        FieldArray fields_ret;
+        if (db_->GetFields(options, key.slice(), &fields_ret).ok()) {
+          found++;
+        }
+        thread->stats.FinishedSingleOp();
+      }
     } else {
       // Special thread that keeps creating index until other threads are done.
       if (db_->GetIndexStatus("age") != IndexStatus::Exist) {
           std::fprintf(stderr, "index status error in WriteWhileDeleting\n");
           std::exit(1);
       }      
-
-      while (true) {
-        if (db_->GetIndexStatus("age") == IndexStatus::NotExist) {
-          break;
-        }
-
-        db_->DeleteIndex("age", write_options_);
-      }
-
-      // Do not count any of the preceding work/delay in stats.
-      thread->stats.Start();
+      db_->DeleteIndex("age", write_options_);
     }
   }
 };
diff --git a/test/recover_test.cc b/test/recover_test.cc
index de06aea..3d42f80 100644
--- a/test/recover_test.cc
+++ b/test/recover_test.cc
@@ -45,8 +45,8 @@ TEST(TestParalRecover, Recover) {
     //     std::cerr << "open db failed" << std::endl;
     //     abort();
     // }
-    // db->CreateIndexOnField("address");
-    // db->CreateIndexOnField("age");
+    // db->CreateIndexOnField("address", op);
+    // db->CreateIndexOnField("age", op);
     // int thread_num_ = 4;
     // std::vector<std::thread> threads(thread_num_);
     // threads[0] = std::thread([db](){