diff --git a/dwio/nimble/common/tests/TestUtils.h b/dwio/nimble/common/tests/TestUtils.h
index 9cd14ecc..3c1bb15c 100644
--- a/dwio/nimble/common/tests/TestUtils.h
+++ b/dwio/nimble/common/tests/TestUtils.h
@@ -307,12 +307,14 @@ class InMemoryTrackableReadFile final : public velox::ReadFile {
     NIMBLE_NOT_SUPPORTED("Not used by Nimble");
   }
 
-  void preadv(
+  uint64_t preadv(
       folly::Range<const velox::common::Region*> regions,
       folly::Range<folly::IOBuf*> iobufs) const override {
     VELOX_CHECK_EQ(regions.size(), iobufs.size());
+    uint64_t length = 0;
     for (size_t i = 0; i < regions.size(); ++i) {
       const auto& region = regions[i];
+      length += region.length;
       auto& output = iobufs[i];
       if (shouldProduceChainedBuffers_) {
         chunks_.wlock()->push_back({region.offset, region.length});
@@ -332,6 +334,8 @@ class InMemoryTrackableReadFile final : public velox::ReadFile {
         output.append(region.length);
       }
     }
+
+    return length;
   }
 
   uint64_t size() const final {
diff --git a/dwio/nimble/tablet/TabletReader.cpp b/dwio/nimble/tablet/TabletReader.cpp
index b32f1c1a..ce1c56da 100644
--- a/dwio/nimble/tablet/TabletReader.cpp
+++ b/dwio/nimble/tablet/TabletReader.cpp
@@ -33,16 +33,6 @@
 
 namespace facebook::nimble {
 
-DEFINE_bool(
-    nimble_disable_coalesce,
-    false,
-    "Disable read coalescing in Nimble reader.");
-
-DEFINE_uint64(
-    nimble_coalesce_max_distance,
-    1024 * 1024 * 1.25,
-    "Maximum read coalescing distance in Nimble reader. And gap smaller than this value will be coalesced.");
-
 // Here's the layout of the tablet:
 //
 // stripe 1 streams
@@ -59,6 +49,7 @@ DEFINE_uint64(
 // 2 bytes major version + 2 bytes minor version +
 // 4 bytes magic number.
 namespace {
+
 template <typename T>
 const T* asFlatBuffersRoot(std::string_view content) {
   return flatbuffers::GetRoot<T>(content.data());