diff --git a/fastfield_codecs/Cargo.toml b/fastfield_codecs/Cargo.toml
index a53a8ceeb..85106f2c5 100644
--- a/fastfield_codecs/Cargo.toml
+++ b/fastfield_codecs/Cargo.toml
@@ -17,7 +17,7 @@ rand = {version="0.8.3", optional= true}
 fastdivide = "0.4"
 log = "0.4"
 itertools = { version = "0.10.3" }
-measure_time = { version="0.8.2", optional=true}
+measure_time = { version="0.8.2" }
 
 [dev-dependencies]
 more-asserts = "0.3.0"
@@ -25,7 +25,7 @@ proptest = "1.0.0"
 rand = "0.8.3"
 
 [features]
-bin = ["prettytable-rs", "rand", "measure_time"]
+bin = ["prettytable-rs", "rand"]
 default = ["bin"]
 unstable = []
 
diff --git a/fastfield_codecs/src/serialize.rs b/fastfield_codecs/src/serialize.rs
index 92f55f5d0..0e9ea0a15 100644
--- a/fastfield_codecs/src/serialize.rs
+++ b/fastfield_codecs/src/serialize.rs
@@ -23,7 +23,8 @@ use std::sync::Arc;
 
 use common::{BinarySerializable, VInt};
 use fastdivide::DividerU64;
-use log::warn;
+use log::{debug, warn};
+use measure_time::debug_time;
 use ownedbytes::OwnedBytes;
 
 use crate::bitpacked::BitpackedCodec;
@@ -183,6 +184,7 @@ fn detect_codec(
 ) -> Option<FastFieldCodecType> {
     let mut estimations = Vec::new();
     for &codec in codecs {
+        debug_time!("estimate time for codec: {:?}", codec);
         let estimation_opt = match codec {
             FastFieldCodecType::Bitpacked => BitpackedCodec::estimate(&column),
             FastFieldCodecType::Linear => LinearCodec::estimate(&column),
@@ -202,6 +204,7 @@ fn detect_codec(
     // codecs
     estimations.retain(|estimation| !estimation.0.is_nan() && estimation.0 != f32::MAX);
     estimations.sort_by(|(score_left, _), (score_right, _)| score_left.total_cmp(score_right));
+    debug!("Chosen Codec {:?}", estimations.first()?.1);
     Some(estimations.first()?.1)
 }
 
@@ -210,6 +213,12 @@ fn serialize_given_codec(
     codec_type: FastFieldCodecType,
     output: &mut impl io::Write,
 ) -> io::Result<()> {
+    debug_time!(
+        "Serialize time for codec: {:?}, num_vals {}",
+        codec_type,
+        column.num_vals()
+    );
+
     match codec_type {
         FastFieldCodecType::Bitpacked => {
             BitpackedCodec::serialize(&column, output)?;
diff --git a/src/fastfield/multivalued/writer.rs b/src/fastfield/multivalued/writer.rs
index 212b49616..b9bd0d403 100644
--- a/src/fastfield/multivalued/writer.rs
+++ b/src/fastfield/multivalued/writer.rs
@@ -3,6 +3,7 @@ use std::sync::Mutex;
 
 use fastfield_codecs::{Column, MonotonicallyMappableToU64, VecColumn};
 use fnv::FnvHashMap;
+use measure_time::debug_time;
 
 use crate::fastfield::{value_to_u64, CompositeFastFieldSerializer, FastFieldType};
 use crate::indexer::doc_id_mapping::DocIdMapping;
@@ -146,6 +147,13 @@ impl MultiValuedFastFieldWriter {
         {
             self.doc_index.push(self.vals.len() as u64);
             let col = VecColumn::from(&self.doc_index[..]);
+
+            debug_time!(
+                "segment-write-multi-fast-field-idx, num_vals {}, field_id {:?}",
+                col.num_vals(),
+                self.field()
+            );
+
             if let Some(doc_id_map) = doc_id_map {
                 let multi_value_start_index = MultivalueStartIndex::new(&col, doc_id_map);
                 serializer.create_auto_detect_u64_fast_field_with_idx(
@@ -158,6 +166,12 @@ impl MultiValuedFastFieldWriter {
             }
         }
         {
+            debug_time!(
+                "segment-write-multi-fast-field-values, num_vals {}, field_id {:?}",
+                self.vals.len(),
+                self.field()
+            );
+
             // Writing the values themselves.
             // TODO FIXME: Use less memory.
             let mut values: Vec<u64> = Vec::new();
diff --git a/src/fastfield/writer.rs b/src/fastfield/writer.rs
index a7d70635b..22a814ed2 100644
--- a/src/fastfield/writer.rs
+++ b/src/fastfield/writer.rs
@@ -4,6 +4,7 @@ use std::io;
 use common;
 use fastfield_codecs::{Column, MonotonicallyMappableToU64};
 use fnv::FnvHashMap;
+use measure_time::debug_time;
 use tantivy_bitpacker::BlockedBitpacker;
 
 use super::multivalued::MultiValuedFastFieldWriter;
@@ -367,6 +368,8 @@ impl IntFastFieldWriter {
             num_vals: self.val_count as u64,
         };
 
+        debug_time!("segment-write-single-field, field_id {:?}", self.field());
+
         serializer.create_auto_detect_u64_fast_field(self.field, fastfield_accessor)?;
 
         Ok(())
diff --git a/src/indexer/merger.rs b/src/indexer/merger.rs
index 210584e8c..97a01b347 100644
--- a/src/indexer/merger.rs
+++ b/src/indexer/merger.rs
@@ -250,7 +250,11 @@ impl IndexMerger {
         mut term_ord_mappings: HashMap<Field, TermOrdinalMapping>,
         doc_id_mapping: &SegmentDocIdMapping,
     ) -> crate::Result<()> {
-        debug_time!("write-fast-fields");
+        debug_time!(
+            "merge-all-fast-fields, num_segments {}, num docs new segment {}",
+            self.readers.len(),
+            doc_id_mapping.len()
+        );
 
         for (field, field_entry) in self.schema.fields() {
             let field_type = field_entry.field_type();
@@ -311,6 +315,12 @@ impl IndexMerger {
         doc_id_mapping: &SegmentDocIdMapping,
     ) -> crate::Result<()> {
         let fast_field_accessor = SortedDocIdColumn::new(&self.readers, doc_id_mapping, field);
+        debug_time!(
+            "merge-single-fast-field, num_vals {}, num_segments {}, field_id {:?}",
+            fast_field_accessor.num_vals(),
+            self.readers.len(),
+            field
+        );
         fast_field_serializer.create_auto_detect_u64_fast_field(field, fast_field_accessor)?;
 
         Ok(())
@@ -458,6 +468,12 @@ impl IndexMerger {
         fast_field_serializer: &mut CompositeFastFieldSerializer,
         doc_id_mapping: &SegmentDocIdMapping,
     ) -> crate::Result<Vec<u64>> {
+        debug_time!(
+            "merge-multi-fast-field-idx, num_segments {}, field_id {:?}",
+            self.readers.len(),
+            field
+        );
+
         let reader_ordinal_and_field_accessors = self
             .readers
             .iter()
@@ -571,6 +587,13 @@ impl IndexMerger {
 
         let fastfield_accessor =
             SortedDocIdMultiValueColumn::new(&self.readers, doc_id_mapping, &offsets, field);
+        debug_time!(
+            "merge-multi-fast-field-values, num_vals {}, num_segments {}, field_id {:?}",
+            fastfield_accessor.num_vals(),
+            self.readers.len(),
+            field
+        );
+
         fast_field_serializer.create_auto_detect_u64_fast_field_with_idx(
             field,
             fastfield_accessor,