diff --git a/Cargo.lock b/Cargo.lock
index 0ceb2c780..0afbdf5ad 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -47,7 +47,7 @@ dependencies = [
  "actix-utils",
  "ahash 0.8.11",
  "base64 0.22.1",
- "bitflags 2.6.0",
+ "bitflags 2.9.0",
  "brotli",
  "bytes",
  "bytestring",
@@ -393,41 +393,23 @@ checksum = "96d30a06541fbafbc7f82ed10c06164cfbd2c401138f6addd8404629c4b16711"
 
 [[package]]
 name = "arroy"
-version = "0.5.0"
+version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dfc5f272f38fa063bbff0a7ab5219404e221493de005e2b4078c62d626ef567e"
+checksum = "4a885313dfac15b64fd61a39d1970a2befa076c69a763434117c5b6163f9fecb"
 dependencies = [
  "bytemuck",
  "byteorder",
  "heed",
- "log",
  "memmap2",
  "nohash",
  "ordered-float",
+ "page_size",
  "rand",
  "rayon",
  "roaring",
  "tempfile",
- "thiserror 1.0.69",
-]
-
-[[package]]
-name = "arroy"
-version = "0.5.0"
-source = "git+https://github.com/meilisearch/arroy/?tag=DO-NOT-DELETE-upgrade-v04-to-v05#053807bf38dc079f25b003f19fc30fbf3613f6e7"
-dependencies = [
- "bytemuck",
- "byteorder",
- "heed",
- "log",
- "memmap2",
- "nohash",
- "ordered-float",
- "rand",
- "rayon",
- "roaring",
- "tempfile",
- "thiserror 1.0.69",
+ "thiserror 2.0.9",
+ "tracing",
 ]
 
 [[package]]
@@ -553,7 +535,7 @@ version = "0.70.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f49d8fed880d473ea71efb9bf597651e77201bdd4893efe54c9e5d65ae04ce6f"
 dependencies = [
- "bitflags 2.6.0",
+ "bitflags 2.9.0",
  "cexpr",
  "clang-sys",
  "itertools 0.13.0",
@@ -599,9 +581,9 @@ checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
 [[package]]
 name = "bitflags"
-version = "2.6.0"
+version = "2.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b048fb63fd8b5923fc5aa7b340d8e156aec7ec02f0c78fa8a6ddc2613f6f71de"
+checksum = "5c8214115b7bf84099f1309324e63141d4c5d7cc26862f97a0a857dbefe165bd"
 dependencies = [
  "serde",
 ]
@@ -2082,7 +2064,7 @@ version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ce20bbb48248608ba4908b45fe36e17e40f56f8c6bb385ecf5d3c4a1e8b05a22"
 dependencies = [
- "bitflags 2.6.0",
+ "bitflags 2.9.0",
  "debugid",
  "fxhash",
  "serde",
@@ -2249,7 +2231,7 @@ version = "0.19.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b903b73e45dc0c6c596f2d37eccece7c1c8bb6e4407b001096387c63d0d93724"
 dependencies = [
- "bitflags 2.6.0",
+ "bitflags 2.9.0",
  "libc",
  "libgit2-sys",
  "log",
@@ -2397,11 +2379,11 @@ checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
 [[package]]
 name = "heed"
-version = "0.20.5"
+version = "0.22.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7d4f449bab7320c56003d37732a917e18798e2f1709d80263face2b4f9436ddb"
+checksum = "6a56c94661ddfb51aa9cdfbf102cfcc340aa69267f95ebccc4af08d7c530d393"
 dependencies = [
- "bitflags 2.6.0",
+ "bitflags 2.9.0",
  "byteorder",
  "heed-traits",
  "heed-types",
@@ -2421,9 +2403,9 @@ checksum = "eb3130048d404c57ce5a1ac61a903696e8fcde7e8c2991e9fcfc1f27c3ef74ff"
 
 [[package]]
 name = "heed-types"
-version = "0.20.1"
+version = "0.21.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9d3f528b053a6d700b2734eabcd0fd49cb8230647aa72958467527b0b7917114"
+checksum = "13c255bdf46e07fb840d120a36dcc81f385140d7191c76a7391672675c01a55d"
 dependencies = [
  "bincode",
  "byteorder",
@@ -2746,7 +2728,6 @@ name = "index-scheduler"
 version = "1.13.3"
 dependencies = [
  "anyhow",
- "arroy 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "big_s",
  "bincode",
  "bumpalo",
@@ -3013,9 +2994,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.169"
+version = "0.2.171"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5aba8db14291edd000dfcc4d620c7ebfb122c613afb886ca8803fa4e128a20a"
+checksum = "c19937216e9d3aa9956d9bb8dfc0b0c8beb6058fc4f7a4dc4d850edf86a237d6"
 
 [[package]]
 name = "libgit2-sys"
@@ -3468,9 +3449,9 @@ checksum = "4ee93343901ab17bd981295f2cf0026d4ad018c7c31ba84549a4ddbb47a45104"
 
 [[package]]
 name = "lmdb-master-sys"
-version = "0.2.4"
+version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "472c3760e2a8d0f61f322fb36788021bb36d573c502b50fa3e2bcaac3ec326c9"
+checksum = "864808e0b19fb6dd3b70ba94ee671b82fce17554cf80aeb0a155c65bb08027df"
 dependencies = [
  "cc",
  "doxygen-rs",
@@ -3513,9 +3494,9 @@ checksum = "9374ef4228402d4b7e403e5838cb880d9ee663314b0a900d5a6aabf0c213552e"
 
 [[package]]
 name = "log"
-version = "0.4.21"
+version = "0.4.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90ed8c1e510134f979dbc4f070f87d4313098b704861a105fe34231c70a3901c"
+checksum = "30bde2b3dc3671ae49d8e2e9f044c7c005836e7a023ee57cffa25ab82764bb9e"
 
 [[package]]
 name = "lzma-rs"
@@ -3726,7 +3707,6 @@ name = "meilitool"
 version = "1.13.3"
 dependencies = [
  "anyhow",
- "arroy 0.5.0 (git+https://github.com/meilisearch/arroy/?tag=DO-NOT-DELETE-upgrade-v04-to-v05)",
  "clap",
  "dump",
  "file-store",
@@ -3761,7 +3741,7 @@ name = "milli"
 version = "1.13.3"
 dependencies = [
  "allocator-api2",
- "arroy 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "arroy",
  "bbqueue",
  "big_s",
  "bimap",
@@ -4129,9 +4109,9 @@ checksum = "ae4512a8f418ac322335255a72361b9ac927e106f4d7fe6ab4d8ac59cb01f7a9"
 
 [[package]]
 name = "once_cell"
-version = "1.20.2"
+version = "1.21.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1261fe7e33c73b354eab43b1273a57c8f967d0391e80353e51f764ac02cf6775"
+checksum = "cde51589ab56b20a6f686b2c68f7a0bd6add753d697abf720d63f8db3ab7b1ad"
 
 [[package]]
 name = "onig"
@@ -4518,7 +4498,7 @@ version = "0.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "731e0d9356b0c25f16f33b5be79b1c57b562f141ebfcdb0ad8ac2c13a24293b4"
 dependencies = [
- "bitflags 2.6.0",
+ "bitflags 2.9.0",
  "hex",
  "lazy_static",
  "procfs-core",
@@ -4531,7 +4511,7 @@ version = "0.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2d3554923a69f4ce04c4a754260c338f505ce22642d3830e049a399fc2059a29"
 dependencies = [
- "bitflags 2.6.0",
+ "bitflags 2.9.0",
  "hex",
 ]
 
@@ -4872,7 +4852,7 @@ version = "1.20.0"
 source = "git+https://github.com/rhaiscript/rhai?rev=ef3df63121d27aacd838f366f2b83fd65f20a1e4#ef3df63121d27aacd838f366f2b83fd65f20a1e4"
 dependencies = [
  "ahash 0.8.11",
- "bitflags 2.6.0",
+ "bitflags 2.9.0",
  "instant",
  "num-traits",
  "once_cell",
@@ -5008,7 +4988,7 @@ version = "0.38.41"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d7f649912bc1495e167a6edee79151c84b1bad49748cb4f1f1167f459f6224f6"
 dependencies = [
- "bitflags 2.6.0",
+ "bitflags 2.9.0",
  "errno",
  "libc",
  "linux-raw-sys",
@@ -5130,9 +5110,9 @@ checksum = "a3f0bf26fd526d2a95683cd0f87bf103b8539e2ca1ef48ce002d67aad59aa0b4"
 
 [[package]]
 name = "serde"
-version = "1.0.217"
+version = "1.0.219"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "02fc4265df13d6fa1d00ecff087228cc0a2b5f3c0e87e258d8b94a156e984c70"
+checksum = "5f0e2c6ed6606019b4e29e69dbaba95b11854410e5347d525002456dbbb786b6"
 dependencies = [
  "serde_derive",
 ]
@@ -5148,9 +5128,9 @@ dependencies = [
 
 [[package]]
 name = "serde_derive"
-version = "1.0.217"
+version = "1.0.219"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a9bf7cf98d04a2b28aead066b7496853d4779c9cc183c440dbac457641e19a0"
+checksum = "5b0276cf7f2c73365f7157c8123c21cd9a50fbbd844757af28ca1f5925fc2a00"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -5159,9 +5139,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.138"
+version = "1.0.140"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d434192e7da787e94a6ea7e9670b26a036d0ca41e0b7efb2676dd32bae872949"
+checksum = "20068b6e96dc6c9bd23e01df8827e6c7e1f2fddd43c21810382803c136b99373"
 dependencies = [
  "indexmap",
  "itoa",
@@ -5529,7 +5509,7 @@ version = "0.5.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ec7dddc5f0fee506baf8b9fdb989e242f17e4b11c61dfbb0635b705217199eea"
 dependencies = [
- "bitflags 2.6.0",
+ "bitflags 2.9.0",
  "byteorder",
  "enum-as-inner",
  "libc",
diff --git a/Cargo.toml b/Cargo.toml
index 0a16810af..320ecfa57 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -36,6 +36,12 @@ license = "MIT"
 [profile.release]
 codegen-units = 1
 
+# We now compile heed without the NDEBUG define for better performance.
+# However, we still enable debug assertions for a better detection of
+# disk corruption on the cloud or in OSS.
+[profile.release.package.heed]
+debug-assertions = true
+
 [profile.dev.package.flate2]
 opt-level = 3
 
diff --git a/crates/benchmarks/benches/indexing.rs b/crates/benchmarks/benches/indexing.rs
index 9938fca26..9199c3877 100644
--- a/crates/benchmarks/benches/indexing.rs
+++ b/crates/benchmarks/benches/indexing.rs
@@ -35,7 +35,8 @@ fn setup_dir(path: impl AsRef<Path>) {
 fn setup_index() -> Index {
     let path = "benches.mmdb";
     setup_dir(path);
-    let mut options = EnvOpenOptions::new();
+    let options = EnvOpenOptions::new();
+    let mut options = options.read_txn_without_tls();
     options.map_size(100 * 1024 * 1024 * 1024); // 100 GB
     options.max_readers(100);
     Index::new(options, path, true).unwrap()
diff --git a/crates/benchmarks/benches/utils.rs b/crates/benchmarks/benches/utils.rs
index 5baeca869..aaa2d50a0 100644
--- a/crates/benchmarks/benches/utils.rs
+++ b/crates/benchmarks/benches/utils.rs
@@ -65,7 +65,8 @@ pub fn base_setup(conf: &Conf) -> Index {
     }
     create_dir_all(conf.database_name).unwrap();
 
-    let mut options = EnvOpenOptions::new();
+    let options = EnvOpenOptions::new();
+    let mut options = options.read_txn_without_tls();
     options.map_size(100 * 1024 * 1024 * 1024); // 100 GB
     options.max_readers(100);
     let index = Index::new(options, conf.database_name, true).unwrap();
diff --git a/crates/fuzzers/src/bin/fuzz-indexing.rs b/crates/fuzzers/src/bin/fuzz-indexing.rs
index e26303010..4df989b51 100644
--- a/crates/fuzzers/src/bin/fuzz-indexing.rs
+++ b/crates/fuzzers/src/bin/fuzz-indexing.rs
@@ -57,7 +57,8 @@ fn main() {
         let opt = opt.clone();
 
         let handle = std::thread::spawn(move || {
-            let mut options = EnvOpenOptions::new();
+            let options = EnvOpenOptions::new();
+            let mut options = options.read_txn_without_tls();
             options.map_size(1024 * 1024 * 1024 * 1024);
             let tempdir = match opt.path {
                 Some(path) => TempDir::new_in(path).unwrap(),
diff --git a/crates/index-scheduler/Cargo.toml b/crates/index-scheduler/Cargo.toml
index 881460d86..37b3ea835 100644
--- a/crates/index-scheduler/Cargo.toml
+++ b/crates/index-scheduler/Cargo.toml
@@ -44,7 +44,6 @@ ureq = "2.12.1"
 uuid = { version = "1.11.0", features = ["serde", "v4"] }
 
 [dev-dependencies]
-arroy = "0.5.0"
 big_s = "1.0.2"
 crossbeam-channel = "0.5.14"
 # fixed version due to format breakages in v1.40
diff --git a/crates/index-scheduler/src/features.rs b/crates/index-scheduler/src/features.rs
index b52b194e6..109e6b867 100644
--- a/crates/index-scheduler/src/features.rs
+++ b/crates/index-scheduler/src/features.rs
@@ -2,7 +2,7 @@ use std::sync::{Arc, RwLock};
 
 use meilisearch_types::features::{InstanceTogglableFeatures, Network, RuntimeTogglableFeatures};
 use meilisearch_types::heed::types::{SerdeJson, Str};
-use meilisearch_types::heed::{Database, Env, RwTxn};
+use meilisearch_types::heed::{Database, Env, RwTxn, WithoutTls};
 
 use crate::error::FeatureNotEnabledError;
 use crate::Result;
@@ -139,7 +139,7 @@ impl FeatureData {
     }
 
     pub fn new(
-        env: &Env,
+        env: &Env<WithoutTls>,
         wtxn: &mut RwTxn,
         instance_features: InstanceTogglableFeatures,
     ) -> Result<Self> {
diff --git a/crates/index-scheduler/src/index_mapper/index_map.rs b/crates/index-scheduler/src/index_mapper/index_map.rs
index e4eb9bfb8..acb95f249 100644
--- a/crates/index-scheduler/src/index_mapper/index_map.rs
+++ b/crates/index-scheduler/src/index_mapper/index_map.rs
@@ -304,7 +304,8 @@ fn create_or_open_index(
     map_size: usize,
     creation: bool,
 ) -> Result<Index> {
-    let mut options = EnvOpenOptions::new();
+    let options = EnvOpenOptions::new();
+    let mut options = options.read_txn_without_tls();
     options.map_size(clamp_to_page_size(map_size));
 
     // You can find more details about this experimental
@@ -333,7 +334,7 @@ fn create_or_open_index(
 #[cfg(test)]
 mod tests {
 
-    use meilisearch_types::heed::Env;
+    use meilisearch_types::heed::{Env, WithoutTls};
     use meilisearch_types::Index;
     use uuid::Uuid;
 
@@ -343,7 +344,7 @@ mod tests {
     use crate::IndexScheduler;
 
     impl IndexMapper {
-        fn test() -> (Self, Env, IndexSchedulerHandle) {
+        fn test() -> (Self, Env<WithoutTls>, IndexSchedulerHandle) {
             let (index_scheduler, handle) = IndexScheduler::test(true, vec![]);
             (index_scheduler.index_mapper, index_scheduler.env, handle)
         }
diff --git a/crates/index-scheduler/src/index_mapper/mod.rs b/crates/index-scheduler/src/index_mapper/mod.rs
index 32cfa94ad..c1f6ff472 100644
--- a/crates/index-scheduler/src/index_mapper/mod.rs
+++ b/crates/index-scheduler/src/index_mapper/mod.rs
@@ -4,7 +4,7 @@ use std::time::Duration;
 use std::{fs, thread};
 
 use meilisearch_types::heed::types::{SerdeJson, Str};
-use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn};
+use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn, WithoutTls};
 use meilisearch_types::milli;
 use meilisearch_types::milli::database_stats::DatabaseStats;
 use meilisearch_types::milli::update::IndexerConfig;
@@ -164,7 +164,7 @@ impl IndexMapper {
     }
 
     pub fn new(
-        env: &Env,
+        env: &Env<WithoutTls>,
         wtxn: &mut RwTxn,
         options: &IndexSchedulerOptions,
         budget: IndexBudget,
diff --git a/crates/index-scheduler/src/lib.rs b/crates/index-scheduler/src/lib.rs
index 3b61b5dc4..70b280301 100644
--- a/crates/index-scheduler/src/lib.rs
+++ b/crates/index-scheduler/src/lib.rs
@@ -54,7 +54,7 @@ use meilisearch_types::batches::Batch;
 use meilisearch_types::features::{InstanceTogglableFeatures, Network, RuntimeTogglableFeatures};
 use meilisearch_types::heed::byteorder::BE;
 use meilisearch_types::heed::types::I128;
-use meilisearch_types::heed::{self, Env, RoTxn};
+use meilisearch_types::heed::{self, Env, RoTxn, WithoutTls};
 use meilisearch_types::milli::index::IndexEmbeddingConfig;
 use meilisearch_types::milli::update::IndexerConfig;
 use meilisearch_types::milli::vector::{Embedder, EmbedderOptions, EmbeddingConfigs};
@@ -131,7 +131,7 @@ pub struct IndexSchedulerOptions {
 /// to be performed on them.
 pub struct IndexScheduler {
     /// The LMDB environment which the DBs are associated with.
-    pub(crate) env: Env,
+    pub(crate) env: Env<WithoutTls>,
 
     /// The list of tasks currently processing
     pub(crate) processing_tasks: Arc<RwLock<ProcessingTasks>>,
@@ -209,6 +209,7 @@ impl IndexScheduler {
     #[allow(private_interfaces)] // because test_utils is private
     pub fn new(
         options: IndexSchedulerOptions,
+        auth_env: Env<WithoutTls>,
         from_db_version: (u32, u32, u32),
         #[cfg(test)] test_breakpoint_sdr: crossbeam_channel::Sender<(test_utils::Breakpoint, bool)>,
         #[cfg(test)] planned_failures: Vec<(usize, test_utils::FailureLocation)>,
@@ -240,7 +241,9 @@ impl IndexScheduler {
         };
 
         let env = unsafe {
-            heed::EnvOpenOptions::new()
+            let env_options = heed::EnvOpenOptions::new();
+            let mut env_options = env_options.read_txn_without_tls();
+            env_options
                 .max_dbs(Self::nb_db())
                 .map_size(budget.task_db_size)
                 .open(&options.tasks_path)
@@ -260,7 +263,7 @@ impl IndexScheduler {
             processing_tasks: Arc::new(RwLock::new(ProcessingTasks::new())),
             version,
             queue,
-            scheduler: Scheduler::new(&options),
+            scheduler: Scheduler::new(&options, auth_env),
 
             index_mapper,
             env,
@@ -358,7 +361,7 @@ impl IndexScheduler {
         }
     }
 
-    pub fn read_txn(&self) -> Result<RoTxn> {
+    pub fn read_txn(&self) -> Result<RoTxn<WithoutTls>> {
         self.env.read_txn().map_err(|e| e.into())
     }
 
@@ -427,12 +430,14 @@ impl IndexScheduler {
     /// If you need to fetch information from or perform an action on all indexes,
     /// see the `try_for_each_index` function.
     pub fn index(&self, name: &str) -> Result<Index> {
-        self.index_mapper.index(&self.env.read_txn()?, name)
+        let rtxn = self.env.read_txn()?;
+        self.index_mapper.index(&rtxn, name)
     }
 
     /// Return the boolean referring if index exists.
     pub fn index_exists(&self, name: &str) -> Result<bool> {
-        self.index_mapper.index_exists(&self.env.read_txn()?, name)
+        let rtxn = self.env.read_txn()?;
+        self.index_mapper.index_exists(&rtxn, name)
     }
 
     /// Return the name of all indexes without opening them.
@@ -507,7 +512,8 @@ impl IndexScheduler {
     /// 2. The name of the specific data related to the property can be `enqueued` for the `statuses`, `settingsUpdate` for the `types`, or the name of the index for the `indexes`, for example.
     /// 3. The number of times the properties appeared.
     pub fn get_stats(&self) -> Result<BTreeMap<String, BTreeMap<String, u64>>> {
-        self.queue.get_stats(&self.read_txn()?, &self.processing_tasks.read().unwrap())
+        let rtxn = self.read_txn()?;
+        self.queue.get_stats(&rtxn, &self.processing_tasks.read().unwrap())
     }
 
     // Return true if there is at least one task that is processing.
diff --git a/crates/index-scheduler/src/queue/batches.rs b/crates/index-scheduler/src/queue/batches.rs
index 970e41110..785d24931 100644
--- a/crates/index-scheduler/src/queue/batches.rs
+++ b/crates/index-scheduler/src/queue/batches.rs
@@ -3,7 +3,7 @@ use std::ops::{Bound, RangeBounds};
 
 use meilisearch_types::batches::{Batch, BatchId};
 use meilisearch_types::heed::types::{DecodeIgnore, SerdeBincode, SerdeJson, Str};
-use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn};
+use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn, WithoutTls};
 use meilisearch_types::milli::{CboRoaringBitmapCodec, RoaringBitmapCodec, BEU32};
 use meilisearch_types::tasks::{Kind, Status};
 use roaring::{MultiOps, RoaringBitmap};
@@ -66,7 +66,7 @@ impl BatchQueue {
         NUMBER_OF_DATABASES
     }
 
-    pub(super) fn new(env: &Env, wtxn: &mut RwTxn) -> Result<Self> {
+    pub(super) fn new(env: &Env<WithoutTls>, wtxn: &mut RwTxn) -> Result<Self> {
         Ok(Self {
             all_batches: env.create_database(wtxn, Some(db_name::ALL_BATCHES))?,
             status: env.create_database(wtxn, Some(db_name::BATCH_STATUS))?,
diff --git a/crates/index-scheduler/src/queue/mod.rs b/crates/index-scheduler/src/queue/mod.rs
index 8850eb8fa..b13e3ffe2 100644
--- a/crates/index-scheduler/src/queue/mod.rs
+++ b/crates/index-scheduler/src/queue/mod.rs
@@ -13,7 +13,7 @@ use std::time::Duration;
 
 use file_store::FileStore;
 use meilisearch_types::batches::BatchId;
-use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn};
+use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn, WithoutTls};
 use meilisearch_types::milli::{CboRoaringBitmapCodec, BEU32};
 use meilisearch_types::tasks::{Kind, KindWithContent, Status, Task};
 use roaring::RoaringBitmap;
@@ -157,7 +157,7 @@ impl Queue {
 
     /// Create an index scheduler and start its run loop.
     pub(crate) fn new(
-        env: &Env,
+        env: &Env<WithoutTls>,
         wtxn: &mut RwTxn,
         options: &IndexSchedulerOptions,
     ) -> Result<Self> {
diff --git a/crates/index-scheduler/src/queue/tasks.rs b/crates/index-scheduler/src/queue/tasks.rs
index 913ebcb30..afe510955 100644
--- a/crates/index-scheduler/src/queue/tasks.rs
+++ b/crates/index-scheduler/src/queue/tasks.rs
@@ -1,7 +1,7 @@
 use std::ops::{Bound, RangeBounds};
 
 use meilisearch_types::heed::types::{DecodeIgnore, SerdeBincode, SerdeJson, Str};
-use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn};
+use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn, WithoutTls};
 use meilisearch_types::milli::{CboRoaringBitmapCodec, RoaringBitmapCodec, BEU32};
 use meilisearch_types::tasks::{Kind, Status, Task};
 use roaring::{MultiOps, RoaringBitmap};
@@ -68,7 +68,7 @@ impl TaskQueue {
         NUMBER_OF_DATABASES
     }
 
-    pub(crate) fn new(env: &Env, wtxn: &mut RwTxn) -> Result<Self> {
+    pub(crate) fn new(env: &Env<WithoutTls>, wtxn: &mut RwTxn) -> Result<Self> {
         Ok(Self {
             all_tasks: env.create_database(wtxn, Some(db_name::ALL_TASKS))?,
             status: env.create_database(wtxn, Some(db_name::STATUS))?,
diff --git a/crates/index-scheduler/src/scheduler/mod.rs b/crates/index-scheduler/src/scheduler/mod.rs
index 41ff7f809..68591d664 100644
--- a/crates/index-scheduler/src/scheduler/mod.rs
+++ b/crates/index-scheduler/src/scheduler/mod.rs
@@ -21,6 +21,7 @@ use std::sync::atomic::{AtomicBool, AtomicU32, Ordering};
 use std::sync::Arc;
 
 use meilisearch_types::error::ResponseError;
+use meilisearch_types::heed::{Env, WithoutTls};
 use meilisearch_types::milli;
 use meilisearch_types::tasks::Status;
 use rayon::current_num_threads;
@@ -71,7 +72,7 @@ pub struct Scheduler {
     pub(crate) snapshots_path: PathBuf,
 
     /// The path to the folder containing the auth LMDB env.
-    pub(crate) auth_path: PathBuf,
+    pub(crate) auth_env: Env<WithoutTls>,
 
     /// The path to the version file of Meilisearch.
     pub(crate) version_file_path: PathBuf,
@@ -87,12 +88,12 @@ impl Scheduler {
             batched_tasks_size_limit: self.batched_tasks_size_limit,
             dumps_path: self.dumps_path.clone(),
             snapshots_path: self.snapshots_path.clone(),
-            auth_path: self.auth_path.clone(),
+            auth_env: self.auth_env.clone(),
             version_file_path: self.version_file_path.clone(),
         }
     }
 
-    pub fn new(options: &IndexSchedulerOptions) -> Scheduler {
+    pub fn new(options: &IndexSchedulerOptions, auth_env: Env<WithoutTls>) -> Scheduler {
         Scheduler {
             must_stop_processing: MustStopProcessing::default(),
             // we want to start the loop right away in case meilisearch was ctrl+Ced while processing things
@@ -102,7 +103,7 @@ impl Scheduler {
             batched_tasks_size_limit: options.batched_tasks_size_limit,
             dumps_path: options.dumps_path.clone(),
             snapshots_path: options.snapshots_path.clone(),
-            auth_path: options.auth_path.clone(),
+            auth_env,
             version_file_path: options.version_file_path.clone(),
         }
     }
diff --git a/crates/index-scheduler/src/scheduler/process_snapshot_creation.rs b/crates/index-scheduler/src/scheduler/process_snapshot_creation.rs
index 3e1a63ce3..f1bafed01 100644
--- a/crates/index-scheduler/src/scheduler/process_snapshot_creation.rs
+++ b/crates/index-scheduler/src/scheduler/process_snapshot_creation.rs
@@ -4,7 +4,6 @@ use std::sync::atomic::Ordering;
 
 use meilisearch_types::heed::CompactionOption;
 use meilisearch_types::milli::progress::{Progress, VariableNameStep};
-use meilisearch_types::milli::{self};
 use meilisearch_types::tasks::{Status, Task};
 use meilisearch_types::{compression, VERSION_FILE_NAME};
 
@@ -28,7 +27,7 @@ impl IndexScheduler {
 
         // 2. Snapshot the index-scheduler LMDB env
         //
-        // When we call copy_to_file, LMDB opens a read transaction by itself,
+        // When we call copy_to_path, LMDB opens a read transaction by itself,
         // we can't provide our own. It is an issue as we would like to know
         // the update files to copy but new ones can be enqueued between the copy
         // of the env and the new transaction we open to retrieve the enqueued tasks.
@@ -42,7 +41,7 @@ impl IndexScheduler {
         progress.update_progress(SnapshotCreationProgress::SnapshotTheIndexScheduler);
         let dst = temp_snapshot_dir.path().join("tasks");
         fs::create_dir_all(&dst)?;
-        self.env.copy_to_file(dst.join("data.mdb"), CompactionOption::Enabled)?;
+        self.env.copy_to_path(dst.join("data.mdb"), CompactionOption::Enabled)?;
 
         // 2.2 Create a read transaction on the index-scheduler
         let rtxn = self.env.read_txn()?;
@@ -81,7 +80,7 @@ impl IndexScheduler {
             let dst = temp_snapshot_dir.path().join("indexes").join(uuid.to_string());
             fs::create_dir_all(&dst)?;
             index
-                .copy_to_file(dst.join("data.mdb"), CompactionOption::Enabled)
+                .copy_to_path(dst.join("data.mdb"), CompactionOption::Enabled)
                 .map_err(|e| Error::from_milli(e, Some(name.to_string())))?;
         }
 
@@ -91,14 +90,7 @@ impl IndexScheduler {
         progress.update_progress(SnapshotCreationProgress::SnapshotTheApiKeys);
         let dst = temp_snapshot_dir.path().join("auth");
         fs::create_dir_all(&dst)?;
-        // TODO We can't use the open_auth_store_env function here but we should
-        let auth = unsafe {
-            milli::heed::EnvOpenOptions::new()
-                .map_size(1024 * 1024 * 1024) // 1 GiB
-                .max_dbs(2)
-                .open(&self.scheduler.auth_path)
-        }?;
-        auth.copy_to_file(dst.join("data.mdb"), CompactionOption::Enabled)?;
+        self.scheduler.auth_env.copy_to_path(dst.join("data.mdb"), CompactionOption::Enabled)?;
 
         // 5. Copy and tarball the flat snapshot
         progress.update_progress(SnapshotCreationProgress::CreateTheTarball);
diff --git a/crates/index-scheduler/src/test_utils.rs b/crates/index-scheduler/src/test_utils.rs
index 072220b6c..3efcc523a 100644
--- a/crates/index-scheduler/src/test_utils.rs
+++ b/crates/index-scheduler/src/test_utils.rs
@@ -5,6 +5,7 @@ use std::time::Duration;
 use big_s::S;
 use crossbeam_channel::RecvTimeoutError;
 use file_store::File;
+use meilisearch_auth::open_auth_store_env;
 use meilisearch_types::document_formats::DocumentFormatError;
 use meilisearch_types::milli::update::IndexDocumentsMethod::ReplaceDocuments;
 use meilisearch_types::milli::update::IndexerConfig;
@@ -120,7 +121,10 @@ impl IndexScheduler {
             )
         });
 
-        let index_scheduler = Self::new(options, version, sender, planned_failures).unwrap();
+        std::fs::create_dir_all(&options.auth_path).unwrap();
+        let auth_env = open_auth_store_env(&options.auth_path).unwrap();
+        let index_scheduler =
+            Self::new(options, auth_env, version, sender, planned_failures).unwrap();
 
         // To be 100% consistent between all test we're going to start the scheduler right now
         // and ensure it's in the expected starting state.
diff --git a/crates/index-scheduler/src/upgrade/mod.rs b/crates/index-scheduler/src/upgrade/mod.rs
index 017685198..86ca755b8 100644
--- a/crates/index-scheduler/src/upgrade/mod.rs
+++ b/crates/index-scheduler/src/upgrade/mod.rs
@@ -1,5 +1,5 @@
 use anyhow::bail;
-use meilisearch_types::heed::{Env, RwTxn};
+use meilisearch_types::heed::{Env, RwTxn, WithoutTls};
 use meilisearch_types::tasks::{Details, KindWithContent, Status, Task};
 use meilisearch_types::versioning::{VERSION_MAJOR, VERSION_MINOR, VERSION_PATCH};
 use time::OffsetDateTime;
@@ -9,13 +9,17 @@ use crate::queue::TaskQueue;
 use crate::versioning::Versioning;
 
 trait UpgradeIndexScheduler {
-    fn upgrade(&self, env: &Env, wtxn: &mut RwTxn, original: (u32, u32, u32))
-        -> anyhow::Result<()>;
+    fn upgrade(
+        &self,
+        env: &Env<WithoutTls>,
+        wtxn: &mut RwTxn,
+        original: (u32, u32, u32),
+    ) -> anyhow::Result<()>;
     fn target_version(&self) -> (u32, u32, u32);
 }
 
 pub fn upgrade_index_scheduler(
-    env: &Env,
+    env: &Env<WithoutTls>,
     versioning: &Versioning,
     from: (u32, u32, u32),
     to: (u32, u32, u32),
@@ -91,7 +95,7 @@ struct ToCurrentNoOp {}
 impl UpgradeIndexScheduler for ToCurrentNoOp {
     fn upgrade(
         &self,
-        _env: &Env,
+        _env: &Env<WithoutTls>,
         _wtxn: &mut RwTxn,
         _original: (u32, u32, u32),
     ) -> anyhow::Result<()> {
diff --git a/crates/index-scheduler/src/versioning.rs b/crates/index-scheduler/src/versioning.rs
index 22132bf5f..107b8e0ba 100644
--- a/crates/index-scheduler/src/versioning.rs
+++ b/crates/index-scheduler/src/versioning.rs
@@ -1,5 +1,5 @@
 use meilisearch_types::heed::types::Str;
-use meilisearch_types::heed::{self, Database, Env, RoTxn, RwTxn};
+use meilisearch_types::heed::{self, Database, Env, RoTxn, RwTxn, WithoutTls};
 use meilisearch_types::milli::heed_codec::version::VersionCodec;
 use meilisearch_types::versioning;
 
@@ -46,12 +46,12 @@ impl Versioning {
     }
 
     /// Return `Self` without checking anything about the version
-    pub fn raw_new(env: &Env, wtxn: &mut RwTxn) -> Result<Self, heed::Error> {
+    pub fn raw_new(env: &Env<WithoutTls>, wtxn: &mut RwTxn) -> Result<Self, heed::Error> {
         let version = env.create_database(wtxn, Some(db_name::VERSION))?;
         Ok(Self { version })
     }
 
-    pub(crate) fn new(env: &Env, db_version: (u32, u32, u32)) -> Result<Self> {
+    pub(crate) fn new(env: &Env<WithoutTls>, db_version: (u32, u32, u32)) -> Result<Self> {
         let mut wtxn = env.write_txn()?;
         let this = Self::raw_new(env, &mut wtxn)?;
         let from = match this.get_version(&wtxn)? {
diff --git a/crates/meilisearch-auth/src/dump.rs b/crates/meilisearch-auth/src/dump.rs
index 8a215d8ae..6a71b636e 100644
--- a/crates/meilisearch-auth/src/dump.rs
+++ b/crates/meilisearch-auth/src/dump.rs
@@ -2,6 +2,7 @@ use std::fs::File;
 use std::io::{BufReader, Write};
 use std::path::Path;
 
+use meilisearch_types::heed::{Env, WithoutTls};
 use serde_json::Deserializer;
 
 use crate::{AuthController, HeedAuthStore, Result};
@@ -9,11 +10,8 @@ use crate::{AuthController, HeedAuthStore, Result};
 const KEYS_PATH: &str = "keys";
 
 impl AuthController {
-    pub fn dump(src: impl AsRef<Path>, dst: impl AsRef<Path>) -> Result<()> {
-        let mut store = HeedAuthStore::new(&src)?;
-
-        // do not attempt to close the database on drop!
-        store.set_drop_on_close(false);
+    pub fn dump(auth_env: Env<WithoutTls>, dst: impl AsRef<Path>) -> Result<()> {
+        let store = HeedAuthStore::new(auth_env)?;
 
         let keys_file_path = dst.as_ref().join(KEYS_PATH);
 
@@ -27,8 +25,8 @@ impl AuthController {
         Ok(())
     }
 
-    pub fn load_dump(src: impl AsRef<Path>, dst: impl AsRef<Path>) -> Result<()> {
-        let store = HeedAuthStore::new(&dst)?;
+    pub fn load_dump(src: impl AsRef<Path>, auth_env: Env<WithoutTls>) -> Result<()> {
+        let store = HeedAuthStore::new(auth_env)?;
 
         let keys_file_path = src.as_ref().join(KEYS_PATH);
 
diff --git a/crates/meilisearch-auth/src/lib.rs b/crates/meilisearch-auth/src/lib.rs
index 4dbf1bf6f..01c986d9f 100644
--- a/crates/meilisearch-auth/src/lib.rs
+++ b/crates/meilisearch-auth/src/lib.rs
@@ -3,11 +3,10 @@ pub mod error;
 mod store;
 
 use std::collections::{HashMap, HashSet};
-use std::path::Path;
-use std::sync::Arc;
 
 use error::{AuthControllerError, Result};
 use maplit::hashset;
+use meilisearch_types::heed::{Env, WithoutTls};
 use meilisearch_types::index_uid_pattern::IndexUidPattern;
 use meilisearch_types::keys::{Action, CreateApiKey, Key, PatchApiKey};
 use meilisearch_types::milli::update::Setting;
@@ -19,19 +18,19 @@ use uuid::Uuid;
 
 #[derive(Clone)]
 pub struct AuthController {
-    store: Arc<HeedAuthStore>,
+    store: HeedAuthStore,
     master_key: Option<String>,
 }
 
 impl AuthController {
-    pub fn new(db_path: impl AsRef<Path>, master_key: &Option<String>) -> Result<Self> {
-        let store = HeedAuthStore::new(db_path)?;
+    pub fn new(auth_env: Env<WithoutTls>, master_key: &Option<String>) -> Result<Self> {
+        let store = HeedAuthStore::new(auth_env)?;
 
         if store.is_empty()? {
             generate_default_keys(&store)?;
         }
 
-        Ok(Self { store: Arc::new(store), master_key: master_key.clone() })
+        Ok(Self { store, master_key: master_key.clone() })
     }
 
     /// Return `Ok(())` if the auth controller is able to access one of its database.
diff --git a/crates/meilisearch-auth/src/store.rs b/crates/meilisearch-auth/src/store.rs
index ef992e836..2fd380194 100644
--- a/crates/meilisearch-auth/src/store.rs
+++ b/crates/meilisearch-auth/src/store.rs
@@ -1,18 +1,16 @@
 use std::borrow::Cow;
 use std::cmp::Reverse;
 use std::collections::HashSet;
-use std::fs::create_dir_all;
 use std::path::Path;
 use std::result::Result as StdResult;
 use std::str;
 use std::str::FromStr;
-use std::sync::Arc;
 
 use hmac::{Hmac, Mac};
-use meilisearch_types::heed::BoxedError;
+use meilisearch_types::heed::{BoxedError, WithoutTls};
 use meilisearch_types::index_uid_pattern::IndexUidPattern;
 use meilisearch_types::keys::KeyId;
-use meilisearch_types::milli;
+use meilisearch_types::milli::heed;
 use meilisearch_types::milli::heed::types::{Bytes, DecodeIgnore, SerdeJson};
 use meilisearch_types::milli::heed::{Database, Env, EnvOpenOptions, RwTxn};
 use sha2::Sha256;
@@ -25,44 +23,32 @@ use super::error::{AuthControllerError, Result};
 use super::{Action, Key};
 
 const AUTH_STORE_SIZE: usize = 1_073_741_824; //1GiB
-const AUTH_DB_PATH: &str = "auth";
 const KEY_DB_NAME: &str = "api-keys";
 const KEY_ID_ACTION_INDEX_EXPIRATION_DB_NAME: &str = "keyid-action-index-expiration";
 
 #[derive(Clone)]
 pub struct HeedAuthStore {
-    env: Arc<Env>,
+    env: Env<WithoutTls>,
     keys: Database<Bytes, SerdeJson<Key>>,
     action_keyid_index_expiration: Database<KeyIdActionCodec, SerdeJson<Option<OffsetDateTime>>>,
-    should_close_on_drop: bool,
 }
 
-impl Drop for HeedAuthStore {
-    fn drop(&mut self) {
-        if self.should_close_on_drop && Arc::strong_count(&self.env) == 1 {
-            self.env.as_ref().clone().prepare_for_closing();
-        }
-    }
-}
-
-pub fn open_auth_store_env(path: &Path) -> milli::heed::Result<milli::heed::Env> {
-    let mut options = EnvOpenOptions::new();
+pub fn open_auth_store_env(path: &Path) -> heed::Result<Env<WithoutTls>> {
+    let options = EnvOpenOptions::new();
+    let mut options = options.read_txn_without_tls();
     options.map_size(AUTH_STORE_SIZE); // 1GB
     options.max_dbs(2);
     unsafe { options.open(path) }
 }
 
 impl HeedAuthStore {
-    pub fn new(path: impl AsRef<Path>) -> Result<Self> {
-        let path = path.as_ref().join(AUTH_DB_PATH);
-        create_dir_all(&path)?;
-        let env = Arc::new(open_auth_store_env(path.as_ref())?);
+    pub fn new(env: Env<WithoutTls>) -> Result<Self> {
         let mut wtxn = env.write_txn()?;
         let keys = env.create_database(&mut wtxn, Some(KEY_DB_NAME))?;
         let action_keyid_index_expiration =
             env.create_database(&mut wtxn, Some(KEY_ID_ACTION_INDEX_EXPIRATION_DB_NAME))?;
         wtxn.commit()?;
-        Ok(Self { env, keys, action_keyid_index_expiration, should_close_on_drop: true })
+        Ok(Self { env, keys, action_keyid_index_expiration })
     }
 
     /// Return `Ok(())` if the auth store is able to access one of its database.
@@ -82,10 +68,6 @@ impl HeedAuthStore {
         Ok(self.env.non_free_pages_size()?)
     }
 
-    pub fn set_drop_on_close(&mut self, v: bool) {
-        self.should_close_on_drop = v;
-    }
-
     pub fn is_empty(&self) -> Result<bool> {
         let rtxn = self.env.read_txn()?;
 
@@ -293,7 +275,7 @@ impl HeedAuthStore {
 /// optionally on a specific index, for a given key.
 pub struct KeyIdActionCodec;
 
-impl<'a> milli::heed::BytesDecode<'a> for KeyIdActionCodec {
+impl<'a> heed::BytesDecode<'a> for KeyIdActionCodec {
     type DItem = (KeyId, Action, Option<&'a [u8]>);
 
     fn bytes_decode(bytes: &'a [u8]) -> StdResult<Self::DItem, BoxedError> {
@@ -310,7 +292,7 @@ impl<'a> milli::heed::BytesDecode<'a> for KeyIdActionCodec {
     }
 }
 
-impl<'a> milli::heed::BytesEncode<'a> for KeyIdActionCodec {
+impl<'a> heed::BytesEncode<'a> for KeyIdActionCodec {
     type EItem = (&'a KeyId, &'a Action, Option<&'a [u8]>);
 
     fn bytes_encode((key_id, action, index): &Self::EItem) -> StdResult<Cow<[u8]>, BoxedError> {
diff --git a/crates/meilisearch-types/src/error.rs b/crates/meilisearch-types/src/error.rs
index 84bfa0aa9..859563d8a 100644
--- a/crates/meilisearch-types/src/error.rs
+++ b/crates/meilisearch-types/src/error.rs
@@ -407,7 +407,7 @@ impl ErrorCode for milli::Error {
                 match error {
                     // TODO: wait for spec for new error codes.
                     UserError::SerdeJson(_)
-                    | UserError::InvalidLmdbOpenOptions
+                    | UserError::EnvAlreadyOpened
                     | UserError::DocumentLimitReached
                     | UserError::UnknownInternalDocumentId { .. } => Code::Internal,
                     UserError::InvalidStoreFile => Code::InvalidStoreFile,
@@ -504,8 +504,7 @@ impl ErrorCode for HeedError {
             HeedError::Mdb(_)
             | HeedError::Encoding(_)
             | HeedError::Decoding(_)
-            | HeedError::DatabaseClosing
-            | HeedError::BadOpenOptions { .. } => Code::Internal,
+            | HeedError::EnvAlreadyOpened => Code::Internal,
         }
     }
 }
diff --git a/crates/meilisearch/src/lib.rs b/crates/meilisearch/src/lib.rs
index 948d1148b..1841d5556 100644
--- a/crates/meilisearch/src/lib.rs
+++ b/crates/meilisearch/src/lib.rs
@@ -34,7 +34,7 @@ use error::PayloadError;
 use extractors::payload::PayloadConfig;
 use index_scheduler::versioning::Versioning;
 use index_scheduler::{IndexScheduler, IndexSchedulerOptions};
-use meilisearch_auth::AuthController;
+use meilisearch_auth::{open_auth_store_env, AuthController};
 use meilisearch_types::milli::constants::VERSION_MAJOR;
 use meilisearch_types::milli::documents::{DocumentsBatchBuilder, DocumentsBatchReader};
 use meilisearch_types::milli::update::{IndexDocumentsConfig, IndexDocumentsMethod};
@@ -335,9 +335,12 @@ fn open_or_create_database_unchecked(
 ) -> anyhow::Result<(IndexScheduler, AuthController)> {
     // we don't want to create anything in the data.ms yet, thus we
     // wrap our two builders in a closure that'll be executed later.
-    let auth_controller = AuthController::new(&opt.db_path, &opt.master_key);
-    let index_scheduler_builder =
-        || -> anyhow::Result<_> { Ok(IndexScheduler::new(index_scheduler_opt, version)?) };
+    std::fs::create_dir_all(&index_scheduler_opt.auth_path)?;
+    let auth_env = open_auth_store_env(&index_scheduler_opt.auth_path).unwrap();
+    let auth_controller = AuthController::new(auth_env.clone(), &opt.master_key);
+    let index_scheduler_builder = || -> anyhow::Result<_> {
+        Ok(IndexScheduler::new(index_scheduler_opt, auth_env, version)?)
+    };
 
     match (
         index_scheduler_builder(),
@@ -420,6 +423,7 @@ pub fn update_version_file_for_dumpless_upgrade(
     if from_major == 1 && from_minor == 12 {
         let env = unsafe {
             heed::EnvOpenOptions::new()
+                .read_txn_without_tls()
                 .max_dbs(Versioning::nb_db())
                 .map_size(index_scheduler_opt.task_db_size)
                 .open(&index_scheduler_opt.tasks_path)
diff --git a/crates/meilisearch/src/search/mod.rs b/crates/meilisearch/src/search/mod.rs
index d0cab1672..69b306abc 100644
--- a/crates/meilisearch/src/search/mod.rs
+++ b/crates/meilisearch/src/search/mod.rs
@@ -340,7 +340,8 @@ impl SearchKind {
         vector_len: Option<usize>,
         route: Route,
     ) -> Result<(String, Arc<Embedder>, bool), ResponseError> {
-        let embedder_configs = index.embedding_configs(&index.read_txn()?)?;
+        let rtxn = index.read_txn()?;
+        let embedder_configs = index.embedding_configs(&rtxn)?;
         let embedders = index_scheduler.embedders(index_uid, embedder_configs)?;
 
         let (embedder, _, quantized) = embedders
diff --git a/crates/meilisearch/tests/features/mod.rs b/crates/meilisearch/tests/features/mod.rs
index ea11738cc..34cd40e38 100644
--- a/crates/meilisearch/tests/features/mod.rs
+++ b/crates/meilisearch/tests/features/mod.rs
@@ -144,14 +144,6 @@ async fn experimental_feature_metrics() {
     let (response, code) = server.get_metrics().await;
     meili_snap::snapshot!(code, @"200 OK");
     meili_snap::snapshot!(response, @"null");
-
-    // startup without flag respects persisted metrics value
-    let disable_metrics =
-        Opt { experimental_enable_metrics: false, ..default_settings(dir.path()) };
-    let server_no_flag = Server::new_with_options(disable_metrics).await.unwrap();
-    let (response, code) = server_no_flag.get_metrics().await;
-    meili_snap::snapshot!(code, @"200 OK");
-    meili_snap::snapshot!(response, @"null");
 }
 
 #[actix_rt::test]
diff --git a/crates/meilisearch/tests/upgrade/mod.rs b/crates/meilisearch/tests/upgrade/mod.rs
index 4b0cb6330..462305d21 100644
--- a/crates/meilisearch/tests/upgrade/mod.rs
+++ b/crates/meilisearch/tests/upgrade/mod.rs
@@ -64,9 +64,6 @@ async fn version_requires_downgrade() {
 #[actix_rt::test]
 async fn upgrade_to_the_current_version() {
     let temp = tempfile::tempdir().unwrap();
-    let server = Server::new_with_options(default_settings(temp.path())).await.unwrap();
-    drop(server);
-
     let server = Server::new_with_options(Opt {
         experimental_dumpless_upgrade: true,
         ..default_settings(temp.path())
diff --git a/crates/meilisearch/tests/upgrade/v1_12/v1_12_0.rs b/crates/meilisearch/tests/upgrade/v1_12/v1_12_0.rs
index 3e9f2b932..11ba2882a 100644
--- a/crates/meilisearch/tests/upgrade/v1_12/v1_12_0.rs
+++ b/crates/meilisearch/tests/upgrade/v1_12/v1_12_0.rs
@@ -108,6 +108,10 @@ async fn check_the_keys(server: &Server) {
 ///    5.2. Enqueue a new task
 ///    5.3. Create an index
 async fn check_the_index_scheduler(server: &Server) {
+    // Wait until the upgrade has been applied to all indexes to avoid flakyness
+    let (tasks, _) = server.tasks_filter("types=upgradeDatabase&limit=1").await;
+    server.wait_task(Value(tasks["results"][0].clone()).uid()).await.succeeded();
+
     // All the indexes are still present
     let (indexes, _) = server.list_indexes(None, None).await;
     snapshot!(indexes, @r#"
@@ -156,10 +160,6 @@ async fn check_the_index_scheduler(server: &Server) {
     }
     "###);
 
-    // Wait until the upgrade has been applied to all indexes to avoid flakyness
-    let (tasks, _) = server.tasks_filter("types=upgradeDatabase&limit=1").await;
-    server.wait_task(Value(tasks["results"][0].clone()).uid()).await.succeeded();
-
     // Tasks and batches should still work
     // We rewrite the first task for all calls because it may be the upgrade database with unknown dates and duration.
     // The other tasks should NOT change
diff --git a/crates/meilitool/Cargo.toml b/crates/meilitool/Cargo.toml
index ffd13da34..485177838 100644
--- a/crates/meilitool/Cargo.toml
+++ b/crates/meilitool/Cargo.toml
@@ -10,7 +10,6 @@ license.workspace = true
 
 [dependencies]
 anyhow = "1.0.95"
-arroy_v04_to_v05 = { package = "arroy", git = "https://github.com/meilisearch/arroy/", tag = "DO-NOT-DELETE-upgrade-v04-to-v05" }
 clap = { version = "4.5.24", features = ["derive"] }
 dump = { path = "../dump" }
 file-store = { path = "../file-store" }
diff --git a/crates/meilitool/src/main.rs b/crates/meilitool/src/main.rs
index 8a8b774b8..dd1213782 100644
--- a/crates/meilitool/src/main.rs
+++ b/crates/meilitool/src/main.rs
@@ -7,11 +7,11 @@ use anyhow::{bail, Context};
 use clap::{Parser, Subcommand, ValueEnum};
 use dump::{DumpWriter, IndexMetadata};
 use file_store::FileStore;
-use meilisearch_auth::AuthController;
+use meilisearch_auth::{open_auth_store_env, AuthController};
 use meilisearch_types::batches::Batch;
 use meilisearch_types::heed::types::{Bytes, SerdeJson, Str};
 use meilisearch_types::heed::{
-    CompactionOption, Database, Env, EnvOpenOptions, RoTxn, RwTxn, Unspecified,
+    CompactionOption, Database, Env, EnvOpenOptions, RoTxn, RwTxn, Unspecified, WithoutTls,
 };
 use meilisearch_types::milli::constants::RESERVED_VECTORS_FIELD_NAME;
 use meilisearch_types::milli::documents::{obkv_to_object, DocumentsBatchReader};
@@ -172,7 +172,7 @@ fn main() -> anyhow::Result<()> {
 /// Clears the task queue located at `db_path`.
 fn clear_task_queue(db_path: PathBuf) -> anyhow::Result<()> {
     let path = db_path.join("tasks");
-    let env = unsafe { EnvOpenOptions::new().max_dbs(100).open(&path) }
+    let env = unsafe { EnvOpenOptions::new().read_txn_without_tls().max_dbs(100).open(&path) }
         .with_context(|| format!("While trying to open {:?}", path.display()))?;
 
     eprintln!("Deleting tasks from the database...");
@@ -225,7 +225,7 @@ fn clear_task_queue(db_path: PathBuf) -> anyhow::Result<()> {
 }
 
 fn try_opening_database<KC: 'static, DC: 'static>(
-    env: &Env,
+    env: &Env<WithoutTls>,
     rtxn: &RoTxn,
     db_name: &str,
 ) -> anyhow::Result<Database<KC, DC>> {
@@ -235,7 +235,7 @@ fn try_opening_database<KC: 'static, DC: 'static>(
 }
 
 fn try_opening_poly_database(
-    env: &Env,
+    env: &Env<WithoutTls>,
     rtxn: &RoTxn,
     db_name: &str,
 ) -> anyhow::Result<Database<Unspecified, Unspecified>> {
@@ -284,13 +284,18 @@ fn export_a_dump(
         FileStore::new(db_path.join("update_files")).context("While opening the FileStore")?;
 
     let index_scheduler_path = db_path.join("tasks");
-    let env = unsafe { EnvOpenOptions::new().max_dbs(100).open(&index_scheduler_path) }
-        .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
+    let env = unsafe {
+        EnvOpenOptions::new().read_txn_without_tls().max_dbs(100).open(&index_scheduler_path)
+    }
+    .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
 
     eprintln!("Dumping the keys...");
 
     // 2. dump the keys
-    let auth_store = AuthController::new(&db_path, &None)
+    let auth_path = db_path.join("auth");
+    std::fs::create_dir_all(&auth_path).context("While creating the auth directory")?;
+    let auth_env = open_auth_store_env(&auth_path).context("While opening the auth store")?;
+    let auth_store = AuthController::new(auth_env, &None)
         .with_context(|| format!("While opening the auth store at {}", db_path.display()))?;
     let mut dump_keys = dump.create_keys()?;
     let mut count = 0;
@@ -386,9 +391,10 @@ fn export_a_dump(
     for result in index_mapping.iter(&rtxn)? {
         let (uid, uuid) = result?;
         let index_path = db_path.join("indexes").join(uuid.to_string());
-        let index = Index::new(EnvOpenOptions::new(), &index_path, false).with_context(|| {
-            format!("While trying to open the index at path {:?}", index_path.display())
-        })?;
+        let index = Index::new(EnvOpenOptions::new().read_txn_without_tls(), &index_path, false)
+            .with_context(|| {
+                format!("While trying to open the index at path {:?}", index_path.display())
+            })?;
 
         let rtxn = index.read_txn()?;
         let metadata = IndexMetadata {
@@ -438,8 +444,10 @@ fn export_a_dump(
 
 fn compact_index(db_path: PathBuf, index_name: &str) -> anyhow::Result<()> {
     let index_scheduler_path = db_path.join("tasks");
-    let env = unsafe { EnvOpenOptions::new().max_dbs(100).open(&index_scheduler_path) }
-        .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
+    let env = unsafe {
+        EnvOpenOptions::new().read_txn_without_tls().max_dbs(100).open(&index_scheduler_path)
+    }
+    .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
 
     let rtxn = env.read_txn()?;
     let index_mapping: Database<Str, UuidCodec> =
@@ -456,9 +464,10 @@ fn compact_index(db_path: PathBuf, index_name: &str) -> anyhow::Result<()> {
         }
 
         let index_path = db_path.join("indexes").join(uuid.to_string());
-        let index = Index::new(EnvOpenOptions::new(), &index_path, false).with_context(|| {
-            format!("While trying to open the index at path {:?}", index_path.display())
-        })?;
+        let index = Index::new(EnvOpenOptions::new().read_txn_without_tls(), &index_path, false)
+            .with_context(|| {
+                format!("While trying to open the index at path {:?}", index_path.display())
+            })?;
 
         eprintln!("Awaiting for a mutable transaction...");
         let _wtxn = index.write_txn().context("While awaiting for a write transaction")?;
@@ -470,7 +479,7 @@ fn compact_index(db_path: PathBuf, index_name: &str) -> anyhow::Result<()> {
         eprintln!("Compacting the index...");
         let before_compaction = Instant::now();
         let new_file = index
-            .copy_to_file(&compacted_index_file_path, CompactionOption::Enabled)
+            .copy_to_path(&compacted_index_file_path, CompactionOption::Enabled)
             .with_context(|| format!("While compacting {}", compacted_index_file_path.display()))?;
 
         let after_size = new_file.metadata()?.len();
@@ -514,8 +523,10 @@ fn export_documents(
     offset: Option<usize>,
 ) -> anyhow::Result<()> {
     let index_scheduler_path = db_path.join("tasks");
-    let env = unsafe { EnvOpenOptions::new().max_dbs(100).open(&index_scheduler_path) }
-        .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
+    let env = unsafe {
+        EnvOpenOptions::new().read_txn_without_tls().max_dbs(100).open(&index_scheduler_path)
+    }
+    .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
 
     let rtxn = env.read_txn()?;
     let index_mapping: Database<Str, UuidCodec> =
@@ -526,9 +537,10 @@ fn export_documents(
         if uid == index_name {
             let index_path = db_path.join("indexes").join(uuid.to_string());
             let index =
-                Index::new(EnvOpenOptions::new(), &index_path, false).with_context(|| {
-                    format!("While trying to open the index at path {:?}", index_path.display())
-                })?;
+                Index::new(EnvOpenOptions::new().read_txn_without_tls(), &index_path, false)
+                    .with_context(|| {
+                        format!("While trying to open the index at path {:?}", index_path.display())
+                    })?;
 
             let rtxn = index.read_txn()?;
             let fields_ids_map = index.fields_ids_map(&rtxn)?;
@@ -616,8 +628,10 @@ fn hair_dryer(
     index_parts: &[IndexPart],
 ) -> anyhow::Result<()> {
     let index_scheduler_path = db_path.join("tasks");
-    let env = unsafe { EnvOpenOptions::new().max_dbs(100).open(&index_scheduler_path) }
-        .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
+    let env = unsafe {
+        EnvOpenOptions::new().read_txn_without_tls().max_dbs(100).open(&index_scheduler_path)
+    }
+    .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
 
     eprintln!("Trying to get a read transaction on the index scheduler...");
 
@@ -630,9 +644,10 @@ fn hair_dryer(
         if index_names.iter().any(|i| i == uid) {
             let index_path = db_path.join("indexes").join(uuid.to_string());
             let index =
-                Index::new(EnvOpenOptions::new(), &index_path, false).with_context(|| {
-                    format!("While trying to open the index at path {:?}", index_path.display())
-                })?;
+                Index::new(EnvOpenOptions::new().read_txn_without_tls(), &index_path, false)
+                    .with_context(|| {
+                        format!("While trying to open the index at path {:?}", index_path.display())
+                    })?;
 
             eprintln!("Trying to get a read transaction on the {uid} index...");
 
diff --git a/crates/meilitool/src/upgrade/v1_10.rs b/crates/meilitool/src/upgrade/v1_10.rs
index 043520e82..ac30055c5 100644
--- a/crates/meilitool/src/upgrade/v1_10.rs
+++ b/crates/meilitool/src/upgrade/v1_10.rs
@@ -2,7 +2,9 @@ use std::path::Path;
 
 use anyhow::{bail, Context};
 use meilisearch_types::heed::types::{SerdeJson, Str};
-use meilisearch_types::heed::{Database, Env, EnvOpenOptions, RoTxn, RwTxn, Unspecified};
+use meilisearch_types::heed::{
+    Database, Env, EnvOpenOptions, RoTxn, RwTxn, Unspecified, WithoutTls,
+};
 use meilisearch_types::milli::index::{db_name, main_key};
 
 use super::v1_9;
@@ -92,7 +94,7 @@ fn update_index_stats(
 
 fn update_date_format(
     index_uid: &str,
-    index_env: &Env,
+    index_env: &Env<WithoutTls>,
     index_wtxn: &mut RwTxn,
 ) -> anyhow::Result<()> {
     let main = try_opening_poly_database(index_env, index_wtxn, db_name::MAIN)
@@ -106,7 +108,7 @@ fn update_date_format(
 
 fn find_rest_embedders(
     index_uid: &str,
-    index_env: &Env,
+    index_env: &Env<WithoutTls>,
     index_txn: &RoTxn,
 ) -> anyhow::Result<Vec<String>> {
     let main = try_opening_poly_database(index_env, index_txn, db_name::MAIN)
@@ -164,8 +166,10 @@ pub fn v1_9_to_v1_10(
     // 2. REST embedders. We don't support this case right now, so bail
 
     let index_scheduler_path = db_path.join("tasks");
-    let env = unsafe { EnvOpenOptions::new().max_dbs(100).open(&index_scheduler_path) }
-        .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
+    let env = unsafe {
+        EnvOpenOptions::new().read_txn_without_tls().max_dbs(100).open(&index_scheduler_path)
+    }
+    .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
 
     let mut sched_wtxn = env.write_txn()?;
 
@@ -205,9 +209,13 @@ pub fn v1_9_to_v1_10(
 
         let index_env = unsafe {
             // FIXME: fetch the 25 magic number from the index file
-            EnvOpenOptions::new().max_dbs(25).open(&index_path).with_context(|| {
-                format!("while opening index {uid} at '{}'", index_path.display())
-            })?
+            EnvOpenOptions::new()
+                .read_txn_without_tls()
+                .max_dbs(25)
+                .open(&index_path)
+                .with_context(|| {
+                    format!("while opening index {uid} at '{}'", index_path.display())
+                })?
         };
 
         let index_txn = index_env.read_txn().with_context(|| {
@@ -252,9 +260,13 @@ pub fn v1_9_to_v1_10(
 
         let index_env = unsafe {
             // FIXME: fetch the 25 magic number from the index file
-            EnvOpenOptions::new().max_dbs(25).open(&index_path).with_context(|| {
-                format!("while opening index {uid} at '{}'", index_path.display())
-            })?
+            EnvOpenOptions::new()
+                .read_txn_without_tls()
+                .max_dbs(25)
+                .open(&index_path)
+                .with_context(|| {
+                    format!("while opening index {uid} at '{}'", index_path.display())
+                })?
         };
 
         let mut index_wtxn = index_env.write_txn().with_context(|| {
diff --git a/crates/meilitool/src/upgrade/v1_11.rs b/crates/meilitool/src/upgrade/v1_11.rs
index 44aeb125f..76d2fc24f 100644
--- a/crates/meilitool/src/upgrade/v1_11.rs
+++ b/crates/meilitool/src/upgrade/v1_11.rs
@@ -23,8 +23,10 @@ pub fn v1_10_to_v1_11(
     println!("Upgrading from v1.10.0 to v1.11.0");
 
     let index_scheduler_path = db_path.join("tasks");
-    let env = unsafe { EnvOpenOptions::new().max_dbs(100).open(&index_scheduler_path) }
-        .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
+    let env = unsafe {
+        EnvOpenOptions::new().read_txn_without_tls().max_dbs(100).open(&index_scheduler_path)
+    }
+    .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
 
     let sched_rtxn = env.read_txn()?;
 
@@ -50,9 +52,13 @@ pub fn v1_10_to_v1_11(
         );
 
         let index_env = unsafe {
-            EnvOpenOptions::new().max_dbs(25).open(&index_path).with_context(|| {
-                format!("while opening index {uid} at '{}'", index_path.display())
-            })?
+            EnvOpenOptions::new()
+                .read_txn_without_tls()
+                .max_dbs(25)
+                .open(&index_path)
+                .with_context(|| {
+                    format!("while opening index {uid} at '{}'", index_path.display())
+                })?
         };
 
         let index_rtxn = index_env.read_txn().with_context(|| {
@@ -76,11 +82,11 @@ pub fn v1_10_to_v1_11(
             try_opening_poly_database(&index_env, &index_wtxn, db_name::VECTOR_ARROY)
                 .with_context(|| format!("while updating date format for index `{uid}`"))?;
 
-        arroy_v04_to_v05::ugrade_from_prev_version(
+        meilisearch_types::milli::arroy::upgrade::cosine_from_0_4_to_0_5(
             &index_rtxn,
-            index_read_database,
+            index_read_database.remap_types(),
             &mut index_wtxn,
-            index_write_database,
+            index_write_database.remap_types(),
         )?;
 
         index_wtxn.commit()?;
diff --git a/crates/meilitool/src/upgrade/v1_12.rs b/crates/meilitool/src/upgrade/v1_12.rs
index 3ad171c31..1dd679eb9 100644
--- a/crates/meilitool/src/upgrade/v1_12.rs
+++ b/crates/meilitool/src/upgrade/v1_12.rs
@@ -115,8 +115,10 @@ fn convert_update_files(db_path: &Path) -> anyhow::Result<()> {
 /// Rebuild field distribution as it was wrongly computed in v1.12.x if x < 3
 fn rebuild_field_distribution(db_path: &Path) -> anyhow::Result<()> {
     let index_scheduler_path = db_path.join("tasks");
-    let env = unsafe { EnvOpenOptions::new().max_dbs(100).open(&index_scheduler_path) }
-        .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
+    let env = unsafe {
+        EnvOpenOptions::new().read_txn_without_tls().max_dbs(100).open(&index_scheduler_path)
+    }
+    .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
 
     let mut sched_wtxn = env.write_txn()?;
 
@@ -173,11 +175,12 @@ fn rebuild_field_distribution(db_path: &Path) -> anyhow::Result<()> {
 
             println!("\t- Rebuilding field distribution");
 
-            let index =
-                meilisearch_types::milli::Index::new(EnvOpenOptions::new(), &index_path, false)
-                    .with_context(|| {
-                        format!("while opening index {uid} at '{}'", index_path.display())
-                    })?;
+            let index = meilisearch_types::milli::Index::new(
+                EnvOpenOptions::new().read_txn_without_tls(),
+                &index_path,
+                false,
+            )
+            .with_context(|| format!("while opening index {uid} at '{}'", index_path.display()))?;
 
             let mut index_txn = index.write_txn()?;
 
diff --git a/crates/milli/Cargo.toml b/crates/milli/Cargo.toml
index 5eb89ea53..dc95135a2 100644
--- a/crates/milli/Cargo.toml
+++ b/crates/milli/Cargo.toml
@@ -28,11 +28,13 @@ flatten-serde-json = { path = "../flatten-serde-json" }
 fst = "0.4.7"
 fxhash = "0.2.1"
 geoutils = "0.5.1"
-grenad = { version = "0.5.0", default-features = false, features = ["rayon", "tempfile"] }
-heed = { version = "0.20.5", default-features = false, features = [
+grenad = { version = "0.5.0", default-features = false, features = [
+    "rayon",
+    "tempfile",
+] }
+heed = { version = "0.22.0", default-features = false, features = [
     "serde-json",
     "serde-bincode",
-    "read-txn-no-tls",
 ] }
 indexmap = { version = "2.7.0", features = ["serde"] }
 json-depth-checker = { path = "../json-depth-checker" }
@@ -85,7 +87,7 @@ rhai = { git = "https://github.com/rhaiscript/rhai", rev = "ef3df63121d27aacd838
     "no_time",
     "sync",
 ] }
-arroy = "0.5.0"
+arroy = "0.6.0"
 rand = "0.8.5"
 tracing = "0.1.41"
 ureq = { version = "2.12.1", features = ["json"] }
@@ -101,7 +103,13 @@ uell = "0.1.0"
 enum-iterator = "2.1.0"
 bbqueue = { git = "https://github.com/meilisearch/bbqueue" }
 flume = { version = "0.11.1", default-features = false }
-utoipa = { version = "5.3.1", features = ["non_strict_integers", "preserve_order", "uuid", "time", "openapi_extensions"] }
+utoipa = { version = "5.3.1", features = [
+    "non_strict_integers",
+    "preserve_order",
+    "uuid",
+    "time",
+    "openapi_extensions",
+] }
 
 [dev-dependencies]
 mimalloc = { version = "0.1.43", default-features = false }
@@ -113,9 +121,7 @@ meili-snap = { path = "../meili-snap" }
 rand = { version = "0.8.5", features = ["small_rng"] }
 
 [features]
-all-tokenizations = [
-    "charabia/default",
-]
+all-tokenizations = ["charabia/default"]
 
 # Use POSIX semaphores instead of SysV semaphores in LMDB
 # For more information on this feature, see heed's Cargo.toml
diff --git a/crates/milli/src/documents/mod.rs b/crates/milli/src/documents/mod.rs
index 88fa38d30..f43f7e842 100644
--- a/crates/milli/src/documents/mod.rs
+++ b/crates/milli/src/documents/mod.rs
@@ -80,9 +80,13 @@ impl DocumentsBatchIndex {
         let mut map = Object::new();
 
         for (k, v) in document.iter() {
-            // TODO: TAMO: update the error type
-            let key =
-                self.0.get_by_left(&k).ok_or(crate::error::InternalError::DatabaseClosing)?.clone();
+            let key = self
+                .0
+                .get_by_left(&k)
+                .ok_or(crate::error::InternalError::FieldIdMapMissingEntry(
+                    FieldIdMapMissingEntry::FieldId { field_id: k, process: "recreate_json" },
+                ))?
+                .clone();
             let value = serde_json::from_slice::<serde_json::Value>(v)
                 .map_err(crate::error::InternalError::SerdeJson)?;
             map.insert(key, value);
diff --git a/crates/milli/src/error.rs b/crates/milli/src/error.rs
index f0972de75..e1098cfa5 100644
--- a/crates/milli/src/error.rs
+++ b/crates/milli/src/error.rs
@@ -33,8 +33,6 @@ pub enum Error {
 
 #[derive(Error, Debug)]
 pub enum InternalError {
-    #[error("{}", HeedError::DatabaseClosing)]
-    DatabaseClosing,
     #[error("missing {} in the {db_name} database", key.unwrap_or("key"))]
     DatabaseMissingEntry { db_name: &'static str, key: Option<&'static str> },
     #[error("missing {key} in the fieldids weights mapping")]
@@ -197,8 +195,8 @@ and can not be more than 511 bytes.", .document_id.to_string()
         valid_fields: BTreeSet<String>,
         hidden_fields: bool,
     },
-    #[error("an environment is already opened with different options")]
-    InvalidLmdbOpenOptions,
+    #[error("An LMDB environment is already opened")]
+    EnvAlreadyOpened,
     #[error("You must specify where `sort` is listed in the rankingRules setting to use the sort parameter at search time.")]
     SortRankingRuleMissing,
     #[error("The database file is in an invalid state.")]
@@ -362,7 +360,8 @@ impl From<arroy::Error> for Error {
             | arroy::Error::UnmatchingDistance { .. }
             | arroy::Error::NeedBuild(_)
             | arroy::Error::MissingKey { .. }
-            | arroy::Error::MissingMetadata(_) => {
+            | arroy::Error::MissingMetadata(_)
+            | arroy::Error::CannotDecodeKeyMode { .. } => {
                 Error::InternalError(InternalError::ArroyError(value))
             }
         }
@@ -516,8 +515,7 @@ impl From<HeedError> for Error {
             // TODO use the encoding
             HeedError::Encoding(_) => InternalError(Serialization(Encoding { db_name: None })),
             HeedError::Decoding(_) => InternalError(Serialization(Decoding { db_name: None })),
-            HeedError::DatabaseClosing => InternalError(DatabaseClosing),
-            HeedError::BadOpenOptions { .. } => UserError(InvalidLmdbOpenOptions),
+            HeedError::EnvAlreadyOpened { .. } => UserError(EnvAlreadyOpened),
         }
     }
 }
diff --git a/crates/milli/src/index.rs b/crates/milli/src/index.rs
index 798cf3073..771d32175 100644
--- a/crates/milli/src/index.rs
+++ b/crates/milli/src/index.rs
@@ -3,7 +3,7 @@ use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
 use std::fs::File;
 use std::path::Path;
 
-use heed::types::*;
+use heed::{types::*, WithoutTls};
 use heed::{CompactionOption, Database, RoTxn, RwTxn, Unspecified};
 use roaring::RoaringBitmap;
 use rstar::RTree;
@@ -110,7 +110,7 @@ pub mod db_name {
 #[derive(Clone)]
 pub struct Index {
     /// The LMDB environment which this index is associated with.
-    pub(crate) env: heed::Env,
+    pub(crate) env: heed::Env<WithoutTls>,
 
     /// Contains many different types (e.g. the fields ids map).
     pub(crate) main: Database<Unspecified, Unspecified>,
@@ -177,7 +177,7 @@ pub struct Index {
 
 impl Index {
     pub fn new_with_creation_dates<P: AsRef<Path>>(
-        mut options: heed::EnvOpenOptions,
+        mut options: heed::EnvOpenOptions<WithoutTls>,
         path: P,
         created_at: time::OffsetDateTime,
         updated_at: time::OffsetDateTime,
@@ -275,7 +275,7 @@ impl Index {
     }
 
     pub fn new<P: AsRef<Path>>(
-        options: heed::EnvOpenOptions,
+        options: heed::EnvOpenOptions<WithoutTls>,
         path: P,
         creation: bool,
     ) -> Result<Index> {
@@ -284,7 +284,7 @@ impl Index {
     }
 
     fn set_creation_dates(
-        env: &heed::Env,
+        env: &heed::Env<WithoutTls>,
         main: Database<Unspecified, Unspecified>,
         created_at: time::OffsetDateTime,
         updated_at: time::OffsetDateTime,
@@ -306,12 +306,12 @@ impl Index {
     }
 
     /// Create a read transaction to be able to read the index.
-    pub fn read_txn(&self) -> heed::Result<RoTxn<'_>> {
+    pub fn read_txn(&self) -> heed::Result<RoTxn<'_, WithoutTls>> {
         self.env.read_txn()
     }
 
     /// Create a static read transaction to be able to read the index without keeping a reference to it.
-    pub fn static_read_txn(&self) -> heed::Result<RoTxn<'static>> {
+    pub fn static_read_txn(&self) -> heed::Result<RoTxn<'static, WithoutTls>> {
         self.env.clone().static_read_txn()
     }
 
@@ -340,8 +340,12 @@ impl Index {
         self.env.info().map_size
     }
 
-    pub fn copy_to_file<P: AsRef<Path>>(&self, path: P, option: CompactionOption) -> Result<File> {
-        self.env.copy_to_file(path, option).map_err(Into::into)
+    pub fn copy_to_file(&self, file: &mut File, option: CompactionOption) -> Result<()> {
+        self.env.copy_to_file(file, option).map_err(Into::into)
+    }
+
+    pub fn copy_to_path<P: AsRef<Path>>(&self, path: P, option: CompactionOption) -> Result<File> {
+        self.env.copy_to_path(path, option).map_err(Into::into)
     }
 
     /// Returns an `EnvClosingEvent` that can be used to wait for the closing event,
@@ -1825,7 +1829,8 @@ pub(crate) mod tests {
     impl TempIndex {
         /// Creates a temporary index
         pub fn new_with_map_size(size: usize) -> Self {
-            let mut options = EnvOpenOptions::new();
+            let options = EnvOpenOptions::new();
+            let mut options = options.read_txn_without_tls();
             options.map_size(size);
             let _tempdir = TempDir::new_in(".").unwrap();
             let inner = Index::new(options, _tempdir.path(), true).unwrap();
diff --git a/crates/milli/src/lib.rs b/crates/milli/src/lib.rs
index 85540c82e..1a6977585 100644
--- a/crates/milli/src/lib.rs
+++ b/crates/milli/src/lib.rs
@@ -83,6 +83,8 @@ pub use self::search::{
 };
 pub use self::update::ChannelCongestion;
 
+pub use arroy;
+
 pub type Result<T> = std::result::Result<T, error::Error>;
 
 pub type Attribute = u32;
diff --git a/crates/milli/src/search/new/tests/integration.rs b/crates/milli/src/search/new/tests/integration.rs
index e718eb39d..4a6cc9b90 100644
--- a/crates/milli/src/search/new/tests/integration.rs
+++ b/crates/milli/src/search/new/tests/integration.rs
@@ -15,7 +15,8 @@ use crate::constants::RESERVED_GEO_FIELD_NAME;
 
 pub fn setup_search_index_with_criteria(criteria: &[Criterion]) -> Index {
     let path = tempfile::tempdir().unwrap();
-    let mut options = EnvOpenOptions::new();
+    let options = EnvOpenOptions::new();
+    let mut options = options.read_txn_without_tls();
     options.map_size(10 * 1024 * 1024); // 10 MB
     let index = Index::new(options, &path, true).unwrap();
 
diff --git a/crates/milli/src/update/facet/mod.rs b/crates/milli/src/update/facet/mod.rs
index 027bb355e..c40916670 100644
--- a/crates/milli/src/update/facet/mod.rs
+++ b/crates/milli/src/update/facet/mod.rs
@@ -352,7 +352,7 @@ pub(crate) mod test_helpers {
 
     use grenad::MergerBuilder;
     use heed::types::Bytes;
-    use heed::{BytesDecode, BytesEncode, Env, RoTxn, RwTxn};
+    use heed::{BytesDecode, BytesEncode, Env, RoTxn, RwTxn, WithoutTls};
     use roaring::RoaringBitmap;
 
     use super::bulk::FacetsUpdateBulkInner;
@@ -390,7 +390,7 @@ pub(crate) mod test_helpers {
         for<'a> BoundCodec:
             BytesEncode<'a> + BytesDecode<'a, DItem = <BoundCodec as BytesEncode<'a>>::EItem>,
     {
-        pub env: Env,
+        pub env: Env<WithoutTls>,
         pub content: heed::Database<FacetGroupKeyCodec<BytesRefCodec>, FacetGroupValueCodec>,
         pub group_size: Cell<u8>,
         pub min_level_size: Cell<u8>,
@@ -412,7 +412,8 @@ pub(crate) mod test_helpers {
             let group_size = group_size.clamp(2, 127);
             let max_group_size = std::cmp::min(127, std::cmp::max(group_size * 2, max_group_size)); // 2*group_size <= x <= 127
             let min_level_size = std::cmp::max(1, min_level_size); // 1 <= x <= inf
-            let mut options = heed::EnvOpenOptions::new();
+            let options = heed::EnvOpenOptions::new();
+            let mut options = options.read_txn_without_tls();
             let options = options.map_size(4096 * 4 * 1000 * 100);
             let tempdir = tempfile::TempDir::new().unwrap();
             let env = unsafe { options.open(tempdir.path()) }.unwrap();
diff --git a/crates/milli/src/update/index_documents/mod.rs b/crates/milli/src/update/index_documents/mod.rs
index ae082284a..a0228e9cf 100644
--- a/crates/milli/src/update/index_documents/mod.rs
+++ b/crates/milli/src/update/index_documents/mod.rs
@@ -520,7 +520,14 @@ where
 
             pool.install(|| {
                 let mut writer = ArroyWrapper::new(vector_arroy, embedder_index, was_quantized);
-                writer.build_and_quantize(wtxn, &mut rng, dimension, is_quantizing, cancel)?;
+                writer.build_and_quantize(
+                    wtxn,
+                    &mut rng,
+                    dimension,
+                    is_quantizing,
+                    self.indexer_config.max_memory,
+                    cancel,
+                )?;
                 Result::Ok(())
             })
             .map_err(InternalError::from)??;
diff --git a/crates/milli/src/update/new/indexer/document_changes.rs b/crates/milli/src/update/new/indexer/document_changes.rs
index f77ac7658..a2388a662 100644
--- a/crates/milli/src/update/new/indexer/document_changes.rs
+++ b/crates/milli/src/update/new/indexer/document_changes.rs
@@ -3,7 +3,7 @@ use std::sync::atomic::Ordering;
 use std::sync::{Arc, RwLock};
 
 use bumpalo::Bump;
-use heed::RoTxn;
+use heed::{RoTxn, WithoutTls};
 use rayon::iter::IndexedParallelIterator;
 
 use super::super::document_change::DocumentChange;
@@ -28,7 +28,7 @@ pub struct DocumentChangeContext<
     /// inside of the DB.
     pub db_fields_ids_map: &'indexer FieldsIdsMap,
     /// A transaction providing data from the DB before all indexing operations
-    pub rtxn: RoTxn<'indexer>,
+    pub rtxn: RoTxn<'indexer, WithoutTls>,
 
     /// Global field id map that is up to date with the current state of the indexing process.
     ///
diff --git a/crates/milli/src/update/new/indexer/mod.rs b/crates/milli/src/update/new/indexer/mod.rs
index 1cd227139..d002317ca 100644
--- a/crates/milli/src/update/new/indexer/mod.rs
+++ b/crates/milli/src/update/new/indexer/mod.rs
@@ -62,6 +62,8 @@ where
     let mut bbbuffers = Vec::new();
     let finished_extraction = AtomicBool::new(false);
 
+    let arroy_memory = grenad_parameters.max_memory;
+
     // We reduce the actual memory used to 5%. The reason we do this here and not in Meilisearch
     // is because we still use the old indexer for the settings and it is highly impacted by the
     // max memory. So we keep the changes here and will remove these changes once we use the new
@@ -200,6 +202,7 @@ where
                 index,
                 wtxn,
                 index_embeddings,
+                arroy_memory,
                 &mut arroy_writers,
                 &indexing_context.must_stop_processing,
             )
diff --git a/crates/milli/src/update/new/indexer/write.rs b/crates/milli/src/update/new/indexer/write.rs
index a8bd3217f..d3fa5e182 100644
--- a/crates/milli/src/update/new/indexer/write.rs
+++ b/crates/milli/src/update/new/indexer/write.rs
@@ -101,6 +101,7 @@ pub fn build_vectors<MSP>(
     index: &Index,
     wtxn: &mut RwTxn<'_>,
     index_embeddings: Vec<IndexEmbeddingConfig>,
+    arroy_memory: Option<usize>,
     arroy_writers: &mut HashMap<u8, (&str, &Embedder, ArroyWrapper, usize)>,
     must_stop_processing: &MSP,
 ) -> Result<()>
@@ -111,10 +112,18 @@ where
         return Ok(());
     }
 
-    let mut rng = rand::rngs::StdRng::seed_from_u64(42);
+    let seed = rand::random();
+    let mut rng = rand::rngs::StdRng::seed_from_u64(seed);
     for (_index, (_embedder_name, _embedder, writer, dimensions)) in arroy_writers {
         let dimensions = *dimensions;
-        writer.build_and_quantize(wtxn, &mut rng, dimensions, false, must_stop_processing)?;
+        writer.build_and_quantize(
+            wtxn,
+            &mut rng,
+            dimensions,
+            false,
+            arroy_memory,
+            must_stop_processing,
+        )?;
     }
 
     index.put_embedding_configs(wtxn, index_embeddings)?;
diff --git a/crates/milli/src/update/upgrade/mod.rs b/crates/milli/src/update/upgrade/mod.rs
index 98cad3dad..7c8dcf64a 100644
--- a/crates/milli/src/update/upgrade/mod.rs
+++ b/crates/milli/src/update/upgrade/mod.rs
@@ -1,15 +1,17 @@
 mod v1_12;
 mod v1_13;
+mod v1_14;
 
 use heed::RwTxn;
 use v1_12::{V1_12_3_To_V1_13_0, V1_12_To_V1_12_3};
-use v1_13::{V1_13_0_To_V1_13_1, V1_13_1_To_Current};
+use v1_13::{V1_13_0_To_V1_13_1, V1_13_1_To_Latest_V1_13};
+use v1_14::Latest_V1_13_To_Latest_V1_14;
 
 use crate::progress::{Progress, VariableNameStep};
 use crate::{Index, InternalError, Result};
 
 trait UpgradeIndex {
-    /// Returns true if the index scheduler must regenerate its cached stats
+    /// Returns `true` if the index scheduler must regenerate its cached stats.
     fn upgrade(
         &self,
         wtxn: &mut RwTxn,
@@ -32,15 +34,17 @@ pub fn upgrade(
         &V1_12_To_V1_12_3 {},
         &V1_12_3_To_V1_13_0 {},
         &V1_13_0_To_V1_13_1 {},
-        &V1_13_1_To_Current {},
+        &V1_13_1_To_Latest_V1_13 {},
+        &Latest_V1_13_To_Latest_V1_14 {},
     ];
 
     let start = match from {
         (1, 12, 0..=2) => 0,
         (1, 12, 3..) => 1,
         (1, 13, 0) => 2,
+        (1, 13, _) => 4,
         // We must handle the current version in the match because in case of a failure some index may have been upgraded but not other.
-        (1, 13, _) => 3,
+        (1, 14, _) => 4,
         (major, minor, patch) => {
             return Err(InternalError::CannotUpgradeToVersion(major, minor, patch).into())
         }
@@ -50,7 +54,6 @@ pub fn upgrade(
     let upgrade_path = &upgrade_functions[start..];
 
     let mut current_version = from;
-
     let mut regenerate_stats = false;
     for (i, upgrade) in upgrade_path.iter().enumerate() {
         let target = upgrade.target_version();
diff --git a/crates/milli/src/update/upgrade/v1_13.rs b/crates/milli/src/update/upgrade/v1_13.rs
index f1d56d9cb..8e5e052bd 100644
--- a/crates/milli/src/update/upgrade/v1_13.rs
+++ b/crates/milli/src/update/upgrade/v1_13.rs
@@ -37,9 +37,9 @@ impl UpgradeIndex for V1_13_0_To_V1_13_1 {
 }
 
 #[allow(non_camel_case_types)]
-pub(super) struct V1_13_1_To_Current();
+pub(super) struct V1_13_1_To_Latest_V1_13();
 
-impl UpgradeIndex for V1_13_1_To_Current {
+impl UpgradeIndex for V1_13_1_To_Latest_V1_13 {
     fn upgrade(
         &self,
         _wtxn: &mut RwTxn,
diff --git a/crates/milli/src/update/upgrade/v1_14.rs b/crates/milli/src/update/upgrade/v1_14.rs
new file mode 100644
index 000000000..039734b75
--- /dev/null
+++ b/crates/milli/src/update/upgrade/v1_14.rs
@@ -0,0 +1,41 @@
+use arroy::distances::Cosine;
+use heed::RwTxn;
+
+use super::UpgradeIndex;
+use crate::progress::Progress;
+use crate::{make_enum_progress, Index, Result};
+
+#[allow(non_camel_case_types)]
+pub(super) struct Latest_V1_13_To_Latest_V1_14();
+
+impl UpgradeIndex for Latest_V1_13_To_Latest_V1_14 {
+    fn upgrade(
+        &self,
+        wtxn: &mut RwTxn,
+        index: &Index,
+        _original: (u32, u32, u32),
+        progress: Progress,
+    ) -> Result<bool> {
+        make_enum_progress! {
+            enum VectorStore {
+                UpdateInternalVersions,
+            }
+        };
+
+        progress.update_progress(VectorStore::UpdateInternalVersions);
+
+        let rtxn = index.read_txn()?;
+        arroy::upgrade::from_0_5_to_0_6::<Cosine>(
+            &rtxn,
+            index.vector_arroy.remap_data_type(),
+            wtxn,
+            index.vector_arroy.remap_data_type(),
+        )?;
+
+        Ok(false)
+    }
+
+    fn target_version(&self) -> (u32, u32, u32) {
+        (1, 14, 0)
+    }
+}
diff --git a/crates/milli/src/vector/mod.rs b/crates/milli/src/vector/mod.rs
index f67912b89..80efc210d 100644
--- a/crates/milli/src/vector/mod.rs
+++ b/crates/milli/src/vector/mod.rs
@@ -86,6 +86,7 @@ impl ArroyWrapper {
         rng: &mut R,
         dimension: usize,
         quantizing: bool,
+        arroy_memory: Option<usize>,
         cancel: &(impl Fn() -> bool + Sync + Send),
     ) -> Result<(), arroy::Error> {
         for index in arroy_db_range_for_embedder(self.embedder_index) {
@@ -105,9 +106,17 @@ impl ArroyWrapper {
                 // sensitive.
                 if quantizing && !self.quantized {
                     let writer = writer.prepare_changing_distance::<BinaryQuantizedCosine>(wtxn)?;
-                    writer.builder(rng).cancel(cancel).build(wtxn)?;
+                    writer
+                        .builder(rng)
+                        .available_memory(arroy_memory.unwrap_or(usize::MAX))
+                        .cancel(cancel)
+                        .build(wtxn)?;
                 } else if writer.need_build(wtxn)? {
-                    writer.builder(rng).cancel(cancel).build(wtxn)?;
+                    writer
+                        .builder(rng)
+                        .available_memory(arroy_memory.unwrap_or(usize::MAX))
+                        .cancel(cancel)
+                        .build(wtxn)?;
                 } else if writer.is_empty(wtxn)? {
                     break;
                 }
diff --git a/crates/milli/tests/search/facet_distribution.rs b/crates/milli/tests/search/facet_distribution.rs
index c5a61da9f..8934cbea4 100644
--- a/crates/milli/tests/search/facet_distribution.rs
+++ b/crates/milli/tests/search/facet_distribution.rs
@@ -12,7 +12,8 @@ use serde_json::{from_value, json};
 #[test]
 fn test_facet_distribution_with_no_facet_values() {
     let path = tempfile::tempdir().unwrap();
-    let mut options = EnvOpenOptions::new();
+    let options = EnvOpenOptions::new();
+    let mut options = options.read_txn_without_tls();
     options.map_size(10 * 1024 * 1024); // 10 MB
     let index = Index::new(options, &path, true).unwrap();
 
diff --git a/crates/milli/tests/search/mod.rs b/crates/milli/tests/search/mod.rs
index 72b124219..c4a94d815 100644
--- a/crates/milli/tests/search/mod.rs
+++ b/crates/milli/tests/search/mod.rs
@@ -34,7 +34,8 @@ pub const CONTENT: &str = include_str!("../assets/test_set.ndjson");
 
 pub fn setup_search_index_with_criteria(criteria: &[Criterion]) -> Index {
     let path = tempfile::tempdir().unwrap();
-    let mut options = EnvOpenOptions::new();
+    let options = EnvOpenOptions::new();
+    let mut options = options.read_txn_without_tls();
     options.map_size(10 * 1024 * 1024); // 10 MB
     let index = Index::new(options, &path, true).unwrap();
 
diff --git a/crates/milli/tests/search/query_criteria.rs b/crates/milli/tests/search/query_criteria.rs
index 3cc747f06..1acc89484 100644
--- a/crates/milli/tests/search/query_criteria.rs
+++ b/crates/milli/tests/search/query_criteria.rs
@@ -262,7 +262,8 @@ fn criteria_mixup() {
 #[test]
 fn criteria_ascdesc() {
     let path = tempfile::tempdir().unwrap();
-    let mut options = EnvOpenOptions::new();
+    let options = EnvOpenOptions::new();
+    let mut options = options.read_txn_without_tls();
     options.map_size(12 * 1024 * 1024); // 10 MB
     let index = Index::new(options, &path, true).unwrap();
 
diff --git a/crates/milli/tests/search/typo_tolerance.rs b/crates/milli/tests/search/typo_tolerance.rs
index 837b5e6b2..3c0717063 100644
--- a/crates/milli/tests/search/typo_tolerance.rs
+++ b/crates/milli/tests/search/typo_tolerance.rs
@@ -108,7 +108,8 @@ fn test_typo_tolerance_two_typo() {
 #[test]
 fn test_typo_disabled_on_word() {
     let tmp = tempdir().unwrap();
-    let mut options = EnvOpenOptions::new();
+    let options = EnvOpenOptions::new();
+    let mut options = options.read_txn_without_tls();
     options.map_size(4096 * 100);
     let index = Index::new(options, tmp.path(), true).unwrap();