diff --git a/Cargo.lock b/Cargo.lock
index 3f42db22b6..d037c8a543 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -33,9 +33,9 @@ dependencies = [
 
 [[package]]
 name = "autocfg"
-version = "1.0.1"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cdb031dd78e28731d87d56cc8ffef4a8f36ca26c38fe2de700543e627f8a464a"
+checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
 [[package]]
 name = "bech32"
@@ -185,9 +185,9 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-epoch"
-version = "0.9.6"
+version = "0.9.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "97242a70df9b89a65d0b6df3c4bf5b9ce03c5b7309019777fbde37e7537f8762"
+checksum = "c00d6d2ea26e8b151d99093005cb442fb9a37aeaca582a03ec70946f49ab5ed9"
 dependencies = [
  "cfg-if",
  "crossbeam-utils",
@@ -198,9 +198,9 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-utils"
-version = "0.8.6"
+version = "0.8.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cfcae03edb34f947e64acdb1c33ec169824e20657e9ecb61cef6c8c74dcb8120"
+checksum = "b5e5bed1f1c269533fa816a0a5492b3545209a205ca1a54842be180eb63a16a6"
 dependencies = [
  "cfg-if",
  "lazy_static",
@@ -401,9 +401,9 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "libc"
-version = "0.2.116"
+version = "0.2.117"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "565dbd88872dbe4cc8a46e527f26483c1d1f7afa6b884a3bd6cd893d4f98da74"
+checksum = "e74d72e0f9b65b5b4ca49a346af3976df0f9c61d550727f349ecd559f251a26c"
 
 [[package]]
 name = "log"
@@ -422,9 +422,9 @@ checksum = "308cc39be01b73d0d18f82a0e7b2a3df85245f84af96fdddc5d202d27e47b86a"
 
 [[package]]
 name = "memmap2"
-version = "0.5.2"
+version = "0.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fe3179b85e1fd8b14447cbebadb75e45a1002f541b925f0bfec366d56a81c56d"
+checksum = "057a3db23999c867821a7a59feb06a578fcb03685e983dff90daf9e7d24ac08f"
 dependencies = [
  "libc",
 ]
@@ -476,6 +476,7 @@ dependencies = [
  "integer-cbrt",
  "integer-sqrt",
  "log",
+ "memmap2",
  "redb",
  "regex",
  "structopt",
@@ -689,9 +690,9 @@ dependencies = [
 
 [[package]]
 name = "semver"
-version = "1.0.4"
+version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "568a8e6258aa33c13358f81fd834adb854c6f7c9468520910a9b1e8fac068012"
+checksum = "0486718e92ec9a68fbed73bb5ef687d71103b142595b406835649bebd33f72c7"
 
 [[package]]
 name = "serde"
@@ -722,9 +723,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.78"
+version = "1.0.79"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d23c1ba4cf0efd44be32017709280b32d1cea5c3f1275c3b6d9e8bc54f758085"
+checksum = "8e8d9fa5c3b304765ce1fd9c4c8a3de2c8db365a5b91be52f186efc675681d95"
 dependencies = [
  "itoa 1.0.1",
  "ryu",
@@ -816,9 +817,9 @@ dependencies = [
 
 [[package]]
 name = "unicode-segmentation"
-version = "1.8.0"
+version = "1.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8895849a949e7845e06bd6dc1aa51731a103c42707010a5b591c0038fb73385b"
+checksum = "7e8820f5d777f6224dc4be3632222971ac30164d4a258d595640799554ebfd99"
 
 [[package]]
 name = "unicode-width"
diff --git a/Cargo.toml b/Cargo.toml
index 65644c6aa8..6268abd62e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,6 +15,7 @@ executable-path = "1.0.0"
 integer-cbrt = "0.1.2"
 integer-sqrt = "0.1.5"
 log = "0.4.14"
+memmap2 = "0.5.3"
 redb = "0.0.4"
 structopt = "0.3.25"
 tempfile = "3.2.0"
diff --git a/src/index.rs b/src/index.rs
index 7e805d4e29..cf11d4cb62 100644
--- a/src/index.rs
+++ b/src/index.rs
@@ -6,9 +6,9 @@ pub(crate) struct Index {
 }
 
 impl Index {
-  const HASH_TO_BLOCK: &'static str = "HASH_TO_BLOCK";
   const HASH_TO_CHILDREN: &'static str = "HASH_TO_CHILDREN";
   const HASH_TO_HEIGHT: &'static str = "HASH_TO_HEIGHT";
+  const HASH_TO_LOCATION: &'static str = "HASH_TO_LOCATION";
   const HEIGHT_TO_HASH: &'static str = "HEIGHT_TO_HASH";
   const OUTPOINT_TO_ORDINAL_RANGES: &'static str = "OUTPOINT_TO_ORDINAL_RANGES";
 
@@ -44,6 +44,8 @@ impl Index {
   }
 
   fn index_ranges(&self) -> Result {
+    log::info!("Indexing ranges…");
+
     let mut height = 0;
     while let Some(block) = self.block(height)? {
       let wtx = self.database.begin_write()?;
@@ -160,42 +162,33 @@ impl Index {
     Ok(())
   }
 
+  fn blockfile_path(&self, i: u64) -> PathBuf {
+    self.blocksdir.join(format!("blk{:05}.dat", i))
+  }
+
   fn index_blockfiles(&self) -> Result {
-    let mut blockfiles = 0;
-    loop {
-      match File::open(self.blocksdir.join(format!("blk{:05}.dat", blockfiles))) {
-        Ok(_) => {}
-        Err(err) => {
-          if err.kind() == io::ErrorKind::NotFound {
-            break;
-          } else {
-            return Err(err.into());
-          }
-        }
-      }
-      blockfiles += 1;
-    }
+    let blockfiles = (0..)
+      .map(|i| self.blockfile_path(i))
+      .take_while(|path| path.is_file())
+      .count();
 
     log::info!("Indexing {} blockfiles…", blockfiles);
 
     for i in 0.. {
-      let blocks = match fs::read(self.blocksdir.join(format!("blk{:05}.dat", i))) {
-        Ok(blocks) => blocks,
-        Err(err) => {
-          if err.kind() == io::ErrorKind::NotFound {
-            break;
-          } else {
-            return Err(err.into());
-          }
-        }
-      };
+      let path = self.blockfile_path(i);
+
+      if !path.is_file() {
+        break;
+      }
+
+      let blocks = unsafe { Mmap::map(&File::open(path)?)? };
 
       let tx = self.database.begin_write()?;
 
       let mut hash_to_children: MultimapTable<[u8], [u8]> =
         tx.open_multimap_table(Self::HASH_TO_CHILDREN)?;
 
-      let mut hash_to_block: Table<[u8], [u8]> = tx.open_table(Self::HASH_TO_BLOCK)?;
+      let mut hash_to_location: Table<[u8], u64> = tx.open_table(Self::HASH_TO_LOCATION)?;
 
       let mut offset = 0;
 
@@ -208,18 +201,15 @@ impl Index {
           break;
         }
 
-        let magic = &blocks[offset..offset + 4];
-        if magic != Network::Bitcoin.magic().to_le_bytes() {
-          return Err(format!("Unknown magic bytes: {:?}", magic).into());
-        }
+        let rest = &blocks[offset..];
 
-        let len = u32::from_le_bytes(blocks[offset + 4..offset + 8].try_into()?) as usize;
-        let start = offset + 8;
-        let end = start + len;
+        if rest.starts_with(&[0, 0, 0, 0]) {
+          break;
+        }
 
-        let bytes = &blocks[start..end];
+        let block = Self::extract_block(rest)?;
 
-        let header = BlockHeader::consensus_decode(&bytes[0..80])?;
+        let header = BlockHeader::consensus_decode(&block[0..80])?;
         let hash = header.block_hash();
 
         if header.prev_blockhash == Default::default() {
@@ -238,14 +228,14 @@ impl Index {
 
         hash_to_children.insert(&header.prev_blockhash, &hash)?;
 
-        hash_to_block.insert(&hash, bytes)?;
+        hash_to_location.insert(&hash, &((i as u64) << 32 | offset as u64))?;
 
-        offset = end;
+        offset = offset + 8 + block.len();
 
         count += 1;
       }
 
-      log::info!("{}/{}: Processed {} blocks…", i + 1, blockfiles, count);
+      log::info!("{}/{}: Processed {} blocks…", i + 1, blockfiles + 1, count);
 
       tx.commit()?;
     }
@@ -254,6 +244,8 @@ impl Index {
   }
 
   fn index_heights(&self) -> Result {
+    log::info!("Indexing heights…");
+
     let write = self.database.begin_write()?;
 
     let read = self.database.begin_read()?;
@@ -289,6 +281,17 @@ impl Index {
     Ok(())
   }
 
+  fn extract_block(blocks: &[u8]) -> Result<&[u8]> {
+    let magic = &blocks[0..4];
+    if magic != Network::Bitcoin.magic().to_le_bytes() {
+      return Err(format!("Unknown magic bytes: {:?}", magic).into());
+    }
+
+    let len = u32::from_le_bytes(blocks[4..8].try_into()?) as usize;
+
+    Ok(&blocks[8..8 + len])
+  }
+
   pub(crate) fn block(&self, height: u64) -> Result<Option<Block>> {
     let tx = self.database.begin_read()?;
 
@@ -299,14 +302,22 @@ impl Index {
       Some(guard) => {
         let hash = guard.to_value();
 
-        let hash_to_block: ReadOnlyTable<[u8], [u8]> = tx.open_table(Self::HASH_TO_BLOCK)?;
+        let hash_to_location: ReadOnlyTable<[u8], u64> = tx.open_table(Self::HASH_TO_LOCATION)?;
+
+        let location = hash_to_location
+          .get(hash)?
+          .ok_or("Could not find block location in index")?
+          .to_value();
+
+        let path = self.blockfile_path(location >> 32);
+
+        let offset = (location & 0xFFFFFFFF) as usize;
+
+        let blocks = unsafe { Mmap::map(&File::open(path)?)? };
+
+        let bytes = Self::extract_block(&blocks[offset..])?;
 
-        Ok(Some(Block::consensus_decode(
-          hash_to_block
-            .get(hash)?
-            .ok_or("Could not find block in index")?
-            .to_value(),
-        )?))
+        Ok(Some(Block::consensus_decode(bytes)?))
       }
     }
   }
diff --git a/src/main.rs b/src/main.rs
index 758c738f72..2c93dc5d53 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -11,6 +11,7 @@ use {
   derive_more::{Display, FromStr},
   integer_cbrt::IntegerCubeRoot,
   integer_sqrt::IntegerSquareRoot,
+  memmap2::Mmap,
   redb::{
     Database, MultimapTable, ReadOnlyMultimapTable, ReadOnlyTable, ReadableMultimapTable,
     ReadableTable, Table,
@@ -19,8 +20,7 @@ use {
     cmp::Ordering,
     collections::VecDeque,
     fmt::{self, Display, Formatter},
-    fs::{self, File},
-    io,
+    fs::File,
     ops::{Add, AddAssign, Deref, Sub},
     path::{Path, PathBuf},
     process,