Merge #3811

3811: Bring back changes from `release-v1.2.0` to `main` r=Kerollmops a=curquiza



Co-authored-by: Loïc Lecrenier <loic.lecrenier@me.com>
Co-authored-by: meili-bors[bot] <89034592+meili-bors[bot]@users.noreply.github.com>
Co-authored-by: Tamo <tamo@meilisearch.com>
Co-authored-by: Filip Bachul <filipbachul@gmail.com>
Co-authored-by: Kerollmops <clement@meilisearch.com>
Co-authored-by: ManyTheFish <many@meilisearch.com>
Co-authored-by: Clément Renault <clement@meilisearch.com>

Cargo.lock

@@ -1794,7 +1794,7 @@ checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
 [[package]]
 name = "heed"
 version = "0.12.5"
-source = "git+https://github.com/meilisearch/heed?tag=v0.12.5#4158a6c484752afaaf9e2530a6ee0e7ab0f24ee8"
+source = "git+https://github.com/meilisearch/heed?tag=v0.12.6#8c5b94225fc949c02bb7b900cc50ffaf6b584b1e"
 dependencies = [
  "byteorder",
  "heed-traits",
@@ -1811,12 +1811,12 @@ dependencies = [
 [[package]]
 name = "heed-traits"
 version = "0.7.0"
-source = "git+https://github.com/meilisearch/heed?tag=v0.12.5#4158a6c484752afaaf9e2530a6ee0e7ab0f24ee8"
+source = "git+https://github.com/meilisearch/heed?tag=v0.12.6#8c5b94225fc949c02bb7b900cc50ffaf6b584b1e"
 
 [[package]]
 name = "heed-types"
 version = "0.7.2"
-source = "git+https://github.com/meilisearch/heed?tag=v0.12.5#4158a6c484752afaaf9e2530a6ee0e7ab0f24ee8"
+source = "git+https://github.com/meilisearch/heed?tag=v0.12.6#8c5b94225fc949c02bb7b900cc50ffaf6b584b1e"
 dependencies = [
  "bincode",
  "heed-traits",

config.toml

@@ -126,3 +126,6 @@ ssl_tickets = false
 # Experimental metrics feature. For more information, see: <https://github.com/meilisearch/meilisearch/discussions/3518>
 # Enables the Prometheus metrics on the `GET /metrics` endpoint.
 experimental_enable_metrics = false
+
+# Experimental RAM reduction during indexing, do not use in production, see: <https://github.com/meilisearch/product/discussions/652>
+experimental_reduce_indexing_memory_usage = false

index-scheduler/src/batch.rs

@@ -24,6 +24,7 @@ use std::io::BufWriter;
 
 use dump::IndexMetadata;
 use log::{debug, error, info};
+use meilisearch_types::error::Code;
 use meilisearch_types::heed::{RoTxn, RwTxn};
 use meilisearch_types::milli::documents::{obkv_to_object, DocumentsBatchReader};
 use meilisearch_types::milli::heed::CompactionOption;
@@ -1491,7 +1492,12 @@ fn delete_document_by_filter(filter: &serde_json::Value, index: Index) -> Result
     Ok(if let Some(filter) = filter {
         let mut wtxn = index.write_txn()?;
 
-        let candidates = filter.evaluate(&wtxn, &index)?;
+        let candidates = filter.evaluate(&wtxn, &index).map_err(|err| match err {
+            milli::Error::UserError(milli::UserError::InvalidFilter(_)) => {
+                Error::from(err).with_custom_error_code(Code::InvalidDocumentFilter)
+            }
+            e => e.into(),
+        })?;
         let mut delete_operation = DeleteDocuments::new(&mut wtxn, &index)?;
         delete_operation.delete_documents(&candidates);
         let deleted_documents =

index-scheduler/src/error.rs

@@ -46,6 +46,8 @@ impl From<DateField> for Code {
 #[allow(clippy::large_enum_variant)]
 #[derive(Error, Debug)]
 pub enum Error {
+    #[error("{1}")]
+    WithCustomErrorCode(Code, Box<Self>),
     #[error("Index `{0}` not found.")]
     IndexNotFound(String),
     #[error("Index `{0}` already exists.")]
@@ -144,6 +146,7 @@ impl Error {
     pub fn is_recoverable(&self) -> bool {
         match self {
             Error::IndexNotFound(_)
+            | Error::WithCustomErrorCode(_, _)
             | Error::IndexAlreadyExists(_)
             | Error::SwapDuplicateIndexFound(_)
             | Error::SwapDuplicateIndexesFound(_)
@@ -176,11 +179,16 @@ impl Error {
             Error::PlannedFailure => false,
         }
     }
+
+    pub fn with_custom_error_code(self, code: Code) -> Self {
+        Self::WithCustomErrorCode(code, Box::new(self))
+    }
 }
 
 impl ErrorCode for Error {
     fn error_code(&self) -> Code {
         match self {
+            Error::WithCustomErrorCode(code, _) => *code,
             Error::IndexNotFound(_) => Code::IndexNotFound,
             Error::IndexAlreadyExists(_) => Code::IndexAlreadyExists,
             Error::SwapDuplicateIndexesFound(_) => Code::InvalidSwapDuplicateIndexFound,

index-scheduler/src/index_mapper/index_map.rs

@@ -5,6 +5,7 @@ use std::collections::BTreeMap;
 use std::path::Path;
 use std::time::Duration;
 
+use meilisearch_types::heed::flags::Flags;
 use meilisearch_types::heed::{EnvClosingEvent, EnvOpenOptions};
 use meilisearch_types::milli::Index;
 use time::OffsetDateTime;
@@ -53,6 +54,7 @@ pub struct IndexMap {
 pub struct ClosingIndex {
     uuid: Uuid,
     closing_event: EnvClosingEvent,
+    enable_mdb_writemap: bool,
     map_size: usize,
     generation: usize,
 }
@@ -68,6 +70,7 @@ impl ClosingIndex {
     pub fn wait_timeout(self, timeout: Duration) -> Option<ReopenableIndex> {
         self.closing_event.wait_timeout(timeout).then_some(ReopenableIndex {
             uuid: self.uuid,
+            enable_mdb_writemap: self.enable_mdb_writemap,
             map_size: self.map_size,
             generation: self.generation,
         })
@@ -76,6 +79,7 @@ impl ClosingIndex {
 
 pub struct ReopenableIndex {
     uuid: Uuid,
+    enable_mdb_writemap: bool,
     map_size: usize,
     generation: usize,
 }
@@ -103,7 +107,7 @@ impl ReopenableIndex {
                 return Ok(());
             }
             map.unavailable.remove(&self.uuid);
-            map.create(&self.uuid, path, None, self.map_size)?;
+            map.create(&self.uuid, path, None, self.enable_mdb_writemap, self.map_size)?;
         }
         Ok(())
     }
@@ -170,16 +174,17 @@ impl IndexMap {
         uuid: &Uuid,
         path: &Path,
         date: Option<(OffsetDateTime, OffsetDateTime)>,
+        enable_mdb_writemap: bool,
         map_size: usize,
     ) -> Result<Index> {
         if !matches!(self.get_unavailable(uuid), Missing) {
             panic!("Attempt to open an index that was unavailable");
         }
-        let index = create_or_open_index(path, date, map_size)?;
+        let index = create_or_open_index(path, date, enable_mdb_writemap, map_size)?;
         match self.available.insert(*uuid, index.clone()) {
             InsertionOutcome::InsertedNew => (),
             InsertionOutcome::Evicted(evicted_uuid, evicted_index) => {
-                self.close(evicted_uuid, evicted_index, 0);
+                self.close(evicted_uuid, evicted_index, enable_mdb_writemap, 0);
             }
             InsertionOutcome::Replaced(_) => {
                 panic!("Attempt to open an index that was already opened")
@@ -212,17 +217,30 @@ impl IndexMap {
     /// | Closing         | Closing       |
     /// | Available       | Closing       |
     ///
-    pub fn close_for_resize(&mut self, uuid: &Uuid, map_size_growth: usize) {
+    pub fn close_for_resize(
+        &mut self,
+        uuid: &Uuid,
+        enable_mdb_writemap: bool,
+        map_size_growth: usize,
+    ) {
         let Some(index) = self.available.remove(uuid) else { return; };
-        self.close(*uuid, index, map_size_growth);
+        self.close(*uuid, index, enable_mdb_writemap, map_size_growth);
     }
 
-    fn close(&mut self, uuid: Uuid, index: Index, map_size_growth: usize) {
+    fn close(
+        &mut self,
+        uuid: Uuid,
+        index: Index,
+        enable_mdb_writemap: bool,
+        map_size_growth: usize,
+    ) {
         let map_size = index.map_size().unwrap_or(DEFAULT_MAP_SIZE) + map_size_growth;
         let closing_event = index.prepare_for_closing();
         let generation = self.next_generation();
-        self.unavailable
+        self.unavailable.insert(
-            .insert(uuid, Some(ClosingIndex { uuid, closing_event, map_size, generation }));
+            uuid,
+            Some(ClosingIndex { uuid, closing_event, enable_mdb_writemap, map_size, generation }),
+        );
     }
 
     /// Attempts to delete and index.
@@ -282,11 +300,15 @@ impl IndexMap {
 fn create_or_open_index(
     path: &Path,
     date: Option<(OffsetDateTime, OffsetDateTime)>,
+    enable_mdb_writemap: bool,
     map_size: usize,
 ) -> Result<Index> {
     let mut options = EnvOpenOptions::new();
     options.map_size(clamp_to_page_size(map_size));
     options.max_readers(1024);
+    if enable_mdb_writemap {
+        unsafe { options.flag(Flags::MdbWriteMap) };
+    }
 
     if let Some((created, updated)) = date {
         Ok(Index::new_with_creation_dates(options, path, created, updated)?)

index-scheduler/src/index_mapper/mod.rs

@@ -66,6 +66,8 @@ pub struct IndexMapper {
     index_base_map_size: usize,
     /// The quantity by which the map size of an index is incremented upon reopening, in bytes.
     index_growth_amount: usize,
+    /// Whether we open a meilisearch index with the MDB_WRITEMAP option or not.
+    enable_mdb_writemap: bool,
     pub indexer_config: Arc<IndexerConfig>,
 }
 
@@ -132,15 +134,22 @@ impl IndexMapper {
         index_base_map_size: usize,
         index_growth_amount: usize,
         index_count: usize,
+        enable_mdb_writemap: bool,
         indexer_config: IndexerConfig,
     ) -> Result<Self> {
+        let mut wtxn = env.write_txn()?;
+        let index_mapping = env.create_database(&mut wtxn, Some(INDEX_MAPPING))?;
+        let index_stats = env.create_database(&mut wtxn, Some(INDEX_STATS))?;
+        wtxn.commit()?;
+
         Ok(Self {
             index_map: Arc::new(RwLock::new(IndexMap::new(index_count))),
-            index_mapping: env.create_database(Some(INDEX_MAPPING))?,
+            index_mapping,
-            index_stats: env.create_database(Some(INDEX_STATS))?,
+            index_stats,
             base_path,
             index_base_map_size,
             index_growth_amount,
+            enable_mdb_writemap,
             indexer_config: Arc::new(indexer_config),
         })
     }
@@ -171,6 +180,7 @@ impl IndexMapper {
                     &uuid,
                     &index_path,
                     date,
+                    self.enable_mdb_writemap,
                     self.index_base_map_size,
                 )?;
 
@@ -282,7 +292,11 @@ impl IndexMapper {
             .ok_or_else(|| Error::IndexNotFound(name.to_string()))?;
 
         // We remove the index from the in-memory index map.
-        self.index_map.write().unwrap().close_for_resize(&uuid, self.index_growth_amount);
+        self.index_map.write().unwrap().close_for_resize(
+            &uuid,
+            self.enable_mdb_writemap,
+            self.index_growth_amount,
+        );
 
         Ok(())
     }
@@ -347,6 +361,7 @@ impl IndexMapper {
                                 &uuid,
                                 &index_path,
                                 None,
+                                self.enable_mdb_writemap,
                                 self.index_base_map_size,
                             )?;
                         }

index-scheduler/src/lib.rs

@@ -233,6 +233,8 @@ pub struct IndexSchedulerOptions {
     pub task_db_size: usize,
     /// The size, in bytes, with which a meilisearch index is opened the first time of each meilisearch index.
     pub index_base_map_size: usize,
+    /// Whether we open a meilisearch index with the MDB_WRITEMAP option or not.
+    pub enable_mdb_writemap: bool,
     /// The size, in bytes, by which the map size of an index is increased when it resized due to being full.
     pub index_growth_amount: usize,
     /// The number of indexes that can be concurrently opened in memory.
@@ -374,6 +376,11 @@ impl IndexScheduler {
         std::fs::create_dir_all(&options.indexes_path)?;
         std::fs::create_dir_all(&options.dumps_path)?;
 
+        if cfg!(windows) && options.enable_mdb_writemap {
+            // programmer error if this happens: in normal use passing the option on Windows is an error in main
+            panic!("Windows doesn't support the MDB_WRITEMAP LMDB option");
+        }
+
         let task_db_size = clamp_to_page_size(options.task_db_size);
         let budget = if options.indexer_config.skip_index_budget {
             IndexBudget {
@@ -396,25 +403,37 @@ impl IndexScheduler {
             .open(options.tasks_path)?;
         let file_store = FileStore::new(&options.update_file_path)?;
 
+        let mut wtxn = env.write_txn()?;
+        let all_tasks = env.create_database(&mut wtxn, Some(db_name::ALL_TASKS))?;
+        let status = env.create_database(&mut wtxn, Some(db_name::STATUS))?;
+        let kind = env.create_database(&mut wtxn, Some(db_name::KIND))?;
+        let index_tasks = env.create_database(&mut wtxn, Some(db_name::INDEX_TASKS))?;
+        let canceled_by = env.create_database(&mut wtxn, Some(db_name::CANCELED_BY))?;
+        let enqueued_at = env.create_database(&mut wtxn, Some(db_name::ENQUEUED_AT))?;
+        let started_at = env.create_database(&mut wtxn, Some(db_name::STARTED_AT))?;
+        let finished_at = env.create_database(&mut wtxn, Some(db_name::FINISHED_AT))?;
+        wtxn.commit()?;
+
         // allow unreachable_code to get rids of the warning in the case of a test build.
         let this = Self {
             must_stop_processing: MustStopProcessing::default(),
             processing_tasks: Arc::new(RwLock::new(ProcessingTasks::new())),
             file_store,
-            all_tasks: env.create_database(Some(db_name::ALL_TASKS))?,
+            all_tasks,
-            status: env.create_database(Some(db_name::STATUS))?,
+            status,
-            kind: env.create_database(Some(db_name::KIND))?,
+            kind,
-            index_tasks: env.create_database(Some(db_name::INDEX_TASKS))?,
+            index_tasks,
-            canceled_by: env.create_database(Some(db_name::CANCELED_BY))?,
+            canceled_by,
-            enqueued_at: env.create_database(Some(db_name::ENQUEUED_AT))?,
+            enqueued_at,
-            started_at: env.create_database(Some(db_name::STARTED_AT))?,
+            started_at,
-            finished_at: env.create_database(Some(db_name::FINISHED_AT))?,
+            finished_at,
             index_mapper: IndexMapper::new(
                 &env,
                 options.indexes_path,
                 budget.map_size,
                 options.index_growth_amount,
                 budget.index_count,
+                options.enable_mdb_writemap,
                 options.indexer_config,
             )?,
             env,
@@ -1509,6 +1528,7 @@ mod tests {
                 dumps_path: tempdir.path().join("dumps"),
                 task_db_size: 1000 * 1000, // 1 MB, we don't use MiB on purpose.
                 index_base_map_size: 1000 * 1000, // 1 MB, we don't use MiB on purpose.
+                enable_mdb_writemap: false,
                 index_growth_amount: 1000 * 1000, // 1 MB
                 index_count: 5,
                 indexer_config,

index-scheduler/src/utils.rs

@@ -466,7 +466,7 @@ impl IndexScheduler {
                         }
                     }
                     Details::DocumentDeletionByFilter { deleted_documents, original_filter: _ } => {
-                        assert_eq!(kind.as_kind(), Kind::DocumentDeletionByFilter);
+                        assert_eq!(kind.as_kind(), Kind::DocumentDeletion);
                         let (index_uid, _) = if let KindWithContent::DocumentDeletionByFilter {
                             ref index_uid,
                             ref filter_expr,

meilisearch-auth/src/store.rs

@@ -55,9 +55,11 @@ impl HeedAuthStore {
         let path = path.as_ref().join(AUTH_DB_PATH);
         create_dir_all(&path)?;
         let env = Arc::new(open_auth_store_env(path.as_ref())?);
-        let keys = env.create_database(Some(KEY_DB_NAME))?;
+        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(Some(KEY_ID_ACTION_INDEX_EXPIRATION_DB_NAME))?;
+            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 })
     }
 

meilisearch-types/src/deserr/mod.rs

@@ -150,6 +150,7 @@ make_missing_field_convenience_builder!(MissingApiKeyActions, missing_api_key_ac
 make_missing_field_convenience_builder!(MissingApiKeyExpiresAt, missing_api_key_expires_at);
 make_missing_field_convenience_builder!(MissingApiKeyIndexes, missing_api_key_indexes);
 make_missing_field_convenience_builder!(MissingSwapIndexes, missing_swap_indexes);
+make_missing_field_convenience_builder!(MissingDocumentFilter, missing_document_filter);
 
 // Integrate a sub-error into a [`DeserrError`] by taking its error message but using
 // the default error code (C) from `Self`

meilisearch-types/src/error.rs

@@ -214,12 +214,12 @@ InvalidApiKeyUid                      , InvalidRequest       , BAD_REQUEST ;
 InvalidContentType                    , InvalidRequest       , UNSUPPORTED_MEDIA_TYPE ;
 InvalidDocumentCsvDelimiter           , InvalidRequest       , BAD_REQUEST ;
 InvalidDocumentFields                 , InvalidRequest       , BAD_REQUEST ;
+MissingDocumentFilter                 , InvalidRequest       , BAD_REQUEST ;
 InvalidDocumentFilter                 , InvalidRequest       , BAD_REQUEST ;
 InvalidDocumentGeoField               , InvalidRequest       , BAD_REQUEST ;
 InvalidDocumentId                     , InvalidRequest       , BAD_REQUEST ;
 InvalidDocumentLimit                  , InvalidRequest       , BAD_REQUEST ;
 InvalidDocumentOffset                 , InvalidRequest       , BAD_REQUEST ;
-InvalidDocumentDeleteFilter           , InvalidRequest       , BAD_REQUEST ;
 InvalidIndexLimit                     , InvalidRequest       , BAD_REQUEST ;
 InvalidIndexOffset                    , InvalidRequest       , BAD_REQUEST ;
 InvalidIndexPrimaryKey                , InvalidRequest       , BAD_REQUEST ;

meilisearch-types/src/tasks.rs

@@ -395,7 +395,6 @@ impl std::error::Error for ParseTaskStatusError {}
 pub enum Kind {
     DocumentAdditionOrUpdate,
     DocumentDeletion,
-    DocumentDeletionByFilter,
     SettingsUpdate,
     IndexCreation,
     IndexDeletion,
@@ -412,7 +411,6 @@ impl Kind {
         match self {
             Kind::DocumentAdditionOrUpdate
             | Kind::DocumentDeletion
-            | Kind::DocumentDeletionByFilter
             | Kind::SettingsUpdate
             | Kind::IndexCreation
             | Kind::IndexDeletion
@@ -430,7 +428,6 @@ impl Display for Kind {
         match self {
             Kind::DocumentAdditionOrUpdate => write!(f, "documentAdditionOrUpdate"),
             Kind::DocumentDeletion => write!(f, "documentDeletion"),
-            Kind::DocumentDeletionByFilter => write!(f, "documentDeletionByFilter"),
             Kind::SettingsUpdate => write!(f, "settingsUpdate"),
             Kind::IndexCreation => write!(f, "indexCreation"),
             Kind::IndexDeletion => write!(f, "indexDeletion"),

meilisearch/src/analytics/mock_analytics.rs

@@ -5,7 +5,7 @@ use actix_web::HttpRequest;
 use meilisearch_types::InstanceUid;
 use serde_json::Value;
 
-use super::{find_user_id, Analytics, DocumentDeletionKind};
+use super::{find_user_id, Analytics, DocumentDeletionKind, DocumentFetchKind};
 use crate::routes::indexes::documents::UpdateDocumentsQuery;
 use crate::routes::tasks::TasksFilterQuery;
 use crate::Opt;
@@ -71,6 +71,8 @@ impl Analytics for MockAnalytics {
         _request: &HttpRequest,
     ) {
     }
+    fn get_fetch_documents(&self, _documents_query: &DocumentFetchKind, _request: &HttpRequest) {}
+    fn post_fetch_documents(&self, _documents_query: &DocumentFetchKind, _request: &HttpRequest) {}
     fn get_tasks(&self, _query: &TasksFilterQuery, _request: &HttpRequest) {}
     fn health_seen(&self, _request: &HttpRequest) {}
 }

meilisearch/src/analytics/mod.rs

@@ -67,6 +67,12 @@ pub enum DocumentDeletionKind {
     PerFilter,
 }
 
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub enum DocumentFetchKind {
+    PerDocumentId,
+    Normal { with_filter: bool, limit: usize, offset: usize },
+}
+
 pub trait Analytics: Sync + Send {
     fn instance_uid(&self) -> Option<&InstanceUid>;
 
@@ -90,6 +96,12 @@ pub trait Analytics: Sync + Send {
         request: &HttpRequest,
     );
 
+    // this method should be called to aggregate a fetch documents request
+    fn get_fetch_documents(&self, documents_query: &DocumentFetchKind, request: &HttpRequest);
+
+    // this method should be called to aggregate a fetch documents request
+    fn post_fetch_documents(&self, documents_query: &DocumentFetchKind, request: &HttpRequest);
+
     // this method should be called to aggregate a add documents request
     fn delete_documents(&self, kind: DocumentDeletionKind, request: &HttpRequest);
 

meilisearch/src/analytics/segment_analytics.rs

@@ -23,7 +23,9 @@ use tokio::select;
 use tokio::sync::mpsc::{self, Receiver, Sender};
 use uuid::Uuid;
 
-use super::{config_user_id_path, DocumentDeletionKind, MEILISEARCH_CONFIG_PATH};
+use super::{
+    config_user_id_path, DocumentDeletionKind, DocumentFetchKind, MEILISEARCH_CONFIG_PATH,
+};
 use crate::analytics::Analytics;
 use crate::option::{default_http_addr, IndexerOpts, MaxMemory, MaxThreads, ScheduleSnapshot};
 use crate::routes::indexes::documents::UpdateDocumentsQuery;
@@ -72,6 +74,8 @@ pub enum AnalyticsMsg {
     AggregateAddDocuments(DocumentsAggregator),
     AggregateDeleteDocuments(DocumentsDeletionAggregator),
     AggregateUpdateDocuments(DocumentsAggregator),
+    AggregateGetFetchDocuments(DocumentsFetchAggregator),
+    AggregatePostFetchDocuments(DocumentsFetchAggregator),
     AggregateTasks(TasksAggregator),
     AggregateHealth(HealthAggregator),
 }
@@ -139,6 +143,8 @@ impl SegmentAnalytics {
             add_documents_aggregator: DocumentsAggregator::default(),
             delete_documents_aggregator: DocumentsDeletionAggregator::default(),
             update_documents_aggregator: DocumentsAggregator::default(),
+            get_fetch_documents_aggregator: DocumentsFetchAggregator::default(),
+            post_fetch_documents_aggregator: DocumentsFetchAggregator::default(),
             get_tasks_aggregator: TasksAggregator::default(),
             health_aggregator: HealthAggregator::default(),
         });
@@ -205,6 +211,16 @@ impl super::Analytics for SegmentAnalytics {
         let _ = self.sender.try_send(AnalyticsMsg::AggregateUpdateDocuments(aggregate));
     }
 
+    fn get_fetch_documents(&self, documents_query: &DocumentFetchKind, request: &HttpRequest) {
+        let aggregate = DocumentsFetchAggregator::from_query(documents_query, request);
+        let _ = self.sender.try_send(AnalyticsMsg::AggregateGetFetchDocuments(aggregate));
+    }
+
+    fn post_fetch_documents(&self, documents_query: &DocumentFetchKind, request: &HttpRequest) {
+        let aggregate = DocumentsFetchAggregator::from_query(documents_query, request);
+        let _ = self.sender.try_send(AnalyticsMsg::AggregatePostFetchDocuments(aggregate));
+    }
+
     fn get_tasks(&self, query: &TasksFilterQuery, request: &HttpRequest) {
         let aggregate = TasksAggregator::from_query(query, request);
         let _ = self.sender.try_send(AnalyticsMsg::AggregateTasks(aggregate));
@@ -225,6 +241,7 @@ impl super::Analytics for SegmentAnalytics {
 struct Infos {
     env: String,
     experimental_enable_metrics: bool,
+    experimental_reduce_indexing_memory_usage: bool,
     db_path: bool,
     import_dump: bool,
     dump_dir: bool,
@@ -258,6 +275,7 @@ impl From<Opt> for Infos {
         let Opt {
             db_path,
             experimental_enable_metrics,
+            experimental_reduce_indexing_memory_usage,
             http_addr,
             master_key: _,
             env,
@@ -300,6 +318,7 @@ impl From<Opt> for Infos {
         Self {
             env,
             experimental_enable_metrics,
+            experimental_reduce_indexing_memory_usage,
             db_path: db_path != PathBuf::from("./data.ms"),
             import_dump: import_dump.is_some(),
             dump_dir: dump_dir != PathBuf::from("dumps/"),
@@ -338,6 +357,8 @@ pub struct Segment {
     add_documents_aggregator: DocumentsAggregator,
     delete_documents_aggregator: DocumentsDeletionAggregator,
     update_documents_aggregator: DocumentsAggregator,
+    get_fetch_documents_aggregator: DocumentsFetchAggregator,
+    post_fetch_documents_aggregator: DocumentsFetchAggregator,
     get_tasks_aggregator: TasksAggregator,
     health_aggregator: HealthAggregator,
 }
@@ -400,6 +421,8 @@ impl Segment {
                         Some(AnalyticsMsg::AggregateAddDocuments(agreg)) => self.add_documents_aggregator.aggregate(agreg),
                         Some(AnalyticsMsg::AggregateDeleteDocuments(agreg)) => self.delete_documents_aggregator.aggregate(agreg),
                         Some(AnalyticsMsg::AggregateUpdateDocuments(agreg)) => self.update_documents_aggregator.aggregate(agreg),
+                        Some(AnalyticsMsg::AggregateGetFetchDocuments(agreg)) => self.get_fetch_documents_aggregator.aggregate(agreg),
+                        Some(AnalyticsMsg::AggregatePostFetchDocuments(agreg)) => self.post_fetch_documents_aggregator.aggregate(agreg),
                         Some(AnalyticsMsg::AggregateTasks(agreg)) => self.get_tasks_aggregator.aggregate(agreg),
                         Some(AnalyticsMsg::AggregateHealth(agreg)) => self.health_aggregator.aggregate(agreg),
                         None => (),
@@ -450,6 +473,10 @@ impl Segment {
             .into_event(&self.user, "Documents Deleted");
         let update_documents = std::mem::take(&mut self.update_documents_aggregator)
             .into_event(&self.user, "Documents Updated");
+        let get_fetch_documents = std::mem::take(&mut self.get_fetch_documents_aggregator)
+            .into_event(&self.user, "Documents Fetched GET");
+        let post_fetch_documents = std::mem::take(&mut self.post_fetch_documents_aggregator)
+            .into_event(&self.user, "Documents Fetched POST");
         let get_tasks =
             std::mem::take(&mut self.get_tasks_aggregator).into_event(&self.user, "Tasks Seen");
         let health =
@@ -473,6 +500,12 @@ impl Segment {
         if let Some(update_documents) = update_documents {
             let _ = self.batcher.push(update_documents).await;
         }
+        if let Some(get_fetch_documents) = get_fetch_documents {
+            let _ = self.batcher.push(get_fetch_documents).await;
+        }
+        if let Some(post_fetch_documents) = post_fetch_documents {
+            let _ = self.batcher.push(post_fetch_documents).await;
+        }
         if let Some(get_tasks) = get_tasks {
             let _ = self.batcher.push(get_tasks).await;
         }
@@ -1135,3 +1168,76 @@ impl HealthAggregator {
         })
     }
 }
+
+#[derive(Default, Serialize)]
+pub struct DocumentsFetchAggregator {
+    #[serde(skip)]
+    timestamp: Option<OffsetDateTime>,
+
+    // context
+    #[serde(rename = "user-agent")]
+    user_agents: HashSet<String>,
+
+    #[serde(rename = "requests.max_limit")]
+    total_received: usize,
+
+    // a call on ../documents/:doc_id
+    per_document_id: bool,
+    // if a filter was used
+    per_filter: bool,
+
+    // pagination
+    #[serde(rename = "pagination.max_limit")]
+    max_limit: usize,
+    #[serde(rename = "pagination.max_offset")]
+    max_offset: usize,
+}
+
+impl DocumentsFetchAggregator {
+    pub fn from_query(query: &DocumentFetchKind, request: &HttpRequest) -> Self {
+        let (limit, offset) = match query {
+            DocumentFetchKind::PerDocumentId => (1, 0),
+            DocumentFetchKind::Normal { limit, offset, .. } => (*limit, *offset),
+        };
+        Self {
+            timestamp: Some(OffsetDateTime::now_utc()),
+            user_agents: extract_user_agents(request).into_iter().collect(),
+            total_received: 1,
+            per_document_id: matches!(query, DocumentFetchKind::PerDocumentId),
+            per_filter: matches!(query, DocumentFetchKind::Normal { with_filter, .. } if *with_filter),
+            max_limit: limit,
+            max_offset: offset,
+        }
+    }
+
+    /// Aggregate one [DocumentsFetchAggregator] into another.
+    pub fn aggregate(&mut self, other: Self) {
+        if self.timestamp.is_none() {
+            self.timestamp = other.timestamp;
+        }
+        for user_agent in other.user_agents {
+            self.user_agents.insert(user_agent);
+        }
+
+        self.total_received = self.total_received.saturating_add(other.total_received);
+        self.per_document_id |= other.per_document_id;
+        self.per_filter |= other.per_filter;
+
+        self.max_limit = self.max_limit.max(other.max_limit);
+        self.max_offset = self.max_offset.max(other.max_offset);
+    }
+
+    pub fn into_event(self, user: &User, event_name: &str) -> Option<Track> {
+        // if we had no timestamp it means we never encountered any events and
+        // thus we don't need to send this event.
+        let timestamp = self.timestamp?;
+
+        Some(Track {
+            timestamp: Some(timestamp),
+            user: user.clone(),
+            event: event_name.to_string(),
+            properties: serde_json::to_value(self).ok()?,
+            ..Default::default()
+        })
+    }
+}

meilisearch/src/error.rs

@@ -1,5 +1,6 @@
 use actix_web as aweb;
 use aweb::error::{JsonPayloadError, QueryPayloadError};
+use byte_unit::Byte;
 use meilisearch_types::document_formats::{DocumentFormatError, PayloadType};
 use meilisearch_types::error::{Code, ErrorCode, ResponseError};
 use meilisearch_types::index_uid::{IndexUid, IndexUidFormatError};
@@ -26,8 +27,8 @@ pub enum MeilisearchHttpError {
     InvalidExpression(&'static [&'static str], Value),
     #[error("A {0} payload is missing.")]
     MissingPayload(PayloadType),
-    #[error("The provided payload reached the size limit.")]
+    #[error("The provided payload reached the size limit. The maximum accepted payload size is {}.",  Byte::from_bytes(*.0 as u64).get_appropriate_unit(true))]
-    PayloadTooLarge,
+    PayloadTooLarge(usize),
     #[error("Two indexes must be given for each swap. The list `[{}]` contains {} indexes.",
         .0.iter().map(|uid| format!("\"{uid}\"")).collect::<Vec<_>>().join(", "), .0.len()
     )]
@@ -60,9 +61,9 @@ impl ErrorCode for MeilisearchHttpError {
             MeilisearchHttpError::MissingPayload(_) => Code::MissingPayload,
             MeilisearchHttpError::InvalidContentType(_, _) => Code::InvalidContentType,
             MeilisearchHttpError::DocumentNotFound(_) => Code::DocumentNotFound,
-            MeilisearchHttpError::EmptyFilter => Code::InvalidDocumentDeleteFilter,
+            MeilisearchHttpError::EmptyFilter => Code::InvalidDocumentFilter,
             MeilisearchHttpError::InvalidExpression(_, _) => Code::InvalidSearchFilter,
-            MeilisearchHttpError::PayloadTooLarge => Code::PayloadTooLarge,
+            MeilisearchHttpError::PayloadTooLarge(_) => Code::PayloadTooLarge,
             MeilisearchHttpError::SwapIndexPayloadWrongLength(_) => Code::InvalidSwapIndexes,
             MeilisearchHttpError::IndexUid(e) => e.error_code(),
             MeilisearchHttpError::SerdeJson(_) => Code::Internal,

meilisearch/src/extractors/payload.rs

@@ -11,6 +11,7 @@ use crate::error::MeilisearchHttpError;
 pub struct Payload {
     payload: Decompress<dev::Payload>,
     limit: usize,
+    remaining: usize,
 }
 
 pub struct PayloadConfig {
@@ -43,6 +44,7 @@ impl FromRequest for Payload {
         ready(Ok(Payload {
             payload: Decompress::from_headers(payload.take(), req.headers()),
             limit,
+            remaining: limit,
         }))
     }
 }
@@ -54,12 +56,14 @@ impl Stream for Payload {
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         match Pin::new(&mut self.payload).poll_next(cx) {
             Poll::Ready(Some(result)) => match result {
-                Ok(bytes) => match self.limit.checked_sub(bytes.len()) {
+                Ok(bytes) => match self.remaining.checked_sub(bytes.len()) {
                     Some(new_limit) => {
-                        self.limit = new_limit;
+                        self.remaining = new_limit;
                         Poll::Ready(Some(Ok(bytes)))
                     }
-                    None => Poll::Ready(Some(Err(MeilisearchHttpError::PayloadTooLarge))),
+                    None => {
+                        Poll::Ready(Some(Err(MeilisearchHttpError::PayloadTooLarge(self.limit))))
+                    }
                 },
                 x => Poll::Ready(Some(x.map_err(MeilisearchHttpError::from))),
             },

meilisearch/src/lib.rs

@@ -232,6 +232,7 @@ fn open_or_create_database_unchecked(
             dumps_path: opt.dump_dir.clone(),
             task_db_size: opt.max_task_db_size.get_bytes() as usize,
             index_base_map_size: opt.max_index_size.get_bytes() as usize,
+            enable_mdb_writemap: opt.experimental_reduce_indexing_memory_usage,
             indexer_config: (&opt.indexer_options).try_into()?,
             autobatching_enabled: true,
             max_number_of_tasks: 1_000_000,

meilisearch/src/main.rs

@@ -29,6 +29,11 @@ fn setup(opt: &Opt) -> anyhow::Result<()> {
 async fn main() -> anyhow::Result<()> {
     let (opt, config_read_from) = Opt::try_build()?;
 
+    anyhow::ensure!(
+        !(cfg!(windows) && opt.experimental_reduce_indexing_memory_usage),
+        "The `experimental-reduce-indexing-memory-usage` flag is not supported on Windows"
+    );
+
     setup(&opt)?;
 
     match (opt.env.as_ref(), &opt.master_key) {

meilisearch/src/option.rs

@@ -48,6 +48,8 @@ const MEILI_IGNORE_DUMP_IF_DB_EXISTS: &str = "MEILI_IGNORE_DUMP_IF_DB_EXISTS";
 const MEILI_DUMP_DIR: &str = "MEILI_DUMP_DIR";
 const MEILI_LOG_LEVEL: &str = "MEILI_LOG_LEVEL";
 const MEILI_EXPERIMENTAL_ENABLE_METRICS: &str = "MEILI_EXPERIMENTAL_ENABLE_METRICS";
+const MEILI_EXPERIMENTAL_REDUCE_INDEXING_MEMORY_USAGE: &str =
+    "MEILI_EXPERIMENTAL_REDUCE_INDEXING_MEMORY_USAGE";
 
 const DEFAULT_CONFIG_FILE_PATH: &str = "./config.toml";
 const DEFAULT_DB_PATH: &str = "./data.ms";
@@ -293,6 +295,11 @@ pub struct Opt {
     #[serde(default)]
     pub experimental_enable_metrics: bool,
 
+    /// Experimental RAM reduction during indexing, do not use in production, see: <https://github.com/meilisearch/product/discussions/652>
+    #[clap(long, env = MEILI_EXPERIMENTAL_REDUCE_INDEXING_MEMORY_USAGE)]
+    #[serde(default)]
+    pub experimental_reduce_indexing_memory_usage: bool,
+
     #[serde(flatten)]
     #[clap(flatten)]
     pub indexer_options: IndexerOpts,
@@ -385,6 +392,7 @@ impl Opt {
             #[cfg(all(not(debug_assertions), feature = "analytics"))]
             no_analytics,
             experimental_enable_metrics: enable_metrics_route,
+            experimental_reduce_indexing_memory_usage: reduce_indexing_memory_usage,
         } = self;
         export_to_env_if_not_present(MEILI_DB_PATH, db_path);
         export_to_env_if_not_present(MEILI_HTTP_ADDR, http_addr);
@@ -426,6 +434,10 @@ impl Opt {
             MEILI_EXPERIMENTAL_ENABLE_METRICS,
             enable_metrics_route.to_string(),
         );
+        export_to_env_if_not_present(
+            MEILI_EXPERIMENTAL_REDUCE_INDEXING_MEMORY_USAGE,
+            reduce_indexing_memory_usage.to_string(),
+        );
         indexer_options.export_to_env();
     }
 

meilisearch/src/routes/indexes/documents.rs

@@ -29,7 +29,7 @@ use tempfile::tempfile;
 use tokio::fs::File;
 use tokio::io::{AsyncSeekExt, AsyncWriteExt, BufWriter};
 
-use crate::analytics::{Analytics, DocumentDeletionKind};
+use crate::analytics::{Analytics, DocumentDeletionKind, DocumentFetchKind};
 use crate::error::MeilisearchHttpError;
 use crate::error::PayloadError::ReceivePayload;
 use crate::extractors::authentication::policies::*;
@@ -97,10 +97,14 @@ pub async fn get_document(
     index_scheduler: GuardedData<ActionPolicy<{ actions::DOCUMENTS_GET }>, Data<IndexScheduler>>,
     document_param: web::Path<DocumentParam>,
     params: AwebQueryParameter<GetDocument, DeserrQueryParamError>,
+    req: HttpRequest,
+    analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     let DocumentParam { index_uid, document_id } = document_param.into_inner();
     let index_uid = IndexUid::try_from(index_uid)?;
 
+    analytics.get_fetch_documents(&DocumentFetchKind::PerDocumentId, &req);
+
     let GetDocument { fields } = params.into_inner();
     let attributes_to_retrieve = fields.merge_star_and_none();
 
@@ -161,16 +165,31 @@ pub async fn documents_by_query_post(
     index_scheduler: GuardedData<ActionPolicy<{ actions::DOCUMENTS_GET }>, Data<IndexScheduler>>,
     index_uid: web::Path<String>,
     body: AwebJson<BrowseQuery, DeserrJsonError>,
+    req: HttpRequest,
+    analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     debug!("called with body: {:?}", body);
 
-    documents_by_query(&index_scheduler, index_uid, body.into_inner())
+    let body = body.into_inner();
+
+    analytics.post_fetch_documents(
+        &DocumentFetchKind::Normal {
+            with_filter: body.filter.is_some(),
+            limit: body.limit,
+            offset: body.offset,
+        },
+        &req,
+    );
+
+    documents_by_query(&index_scheduler, index_uid, body)
 }
 
 pub async fn get_documents(
     index_scheduler: GuardedData<ActionPolicy<{ actions::DOCUMENTS_GET }>, Data<IndexScheduler>>,
     index_uid: web::Path<String>,
     params: AwebQueryParameter<BrowseQueryGet, DeserrQueryParamError>,
+    req: HttpRequest,
+    analytics: web::Data<dyn Analytics>,
 ) -> Result<HttpResponse, ResponseError> {
     debug!("called with params: {:?}", params);
 
@@ -191,6 +210,15 @@ pub async fn get_documents(
         filter,
     };
 
+    analytics.get_fetch_documents(
+        &DocumentFetchKind::Normal {
+            with_filter: query.filter.is_some(),
+            limit: query.limit,
+            offset: query.offset,
+        },
+        &req,
+    );
+
     documents_by_query(&index_scheduler, index_uid, query)
 }
 
@@ -458,7 +486,7 @@ pub async fn delete_documents_batch(
 #[derive(Debug, Deserr)]
 #[deserr(error = DeserrJsonError, rename_all = camelCase, deny_unknown_fields)]
 pub struct DocumentDeletionByFilter {
-    #[deserr(error = DeserrJsonError<InvalidDocumentDeleteFilter>)]
+    #[deserr(error = DeserrJsonError<InvalidDocumentFilter>, missing_field_error = DeserrJsonError::missing_document_filter)]
     filter: Value,
 }
 
@@ -480,8 +508,8 @@ pub async fn delete_documents_by_filter(
     || -> Result<_, ResponseError> {
         Ok(crate::search::parse_filter(&filter)?.ok_or(MeilisearchHttpError::EmptyFilter)?)
     }()
-    // and whatever was the error, the error code should always be an InvalidDocumentDeleteFilter
+    // and whatever was the error, the error code should always be an InvalidDocumentFilter
-    .map_err(|err| ResponseError::from_msg(err.message, Code::InvalidDocumentDeleteFilter))?;
+    .map_err(|err| ResponseError::from_msg(err.message, Code::InvalidDocumentFilter))?;
     let task = KindWithContent::DocumentDeletionByFilter { index_uid, filter_expr: filter };
 
     let task: SummarizedTaskView =
@@ -540,7 +568,12 @@ fn retrieve_documents<S: AsRef<str>>(
     };
 
     let candidates = if let Some(filter) = filter {
-        filter.evaluate(&rtxn, index)?
+        filter.evaluate(&rtxn, index).map_err(|err| match err {
+            milli::Error::UserError(milli::UserError::InvalidFilter(_)) => {
+                ResponseError::from_msg(err.to_string(), Code::InvalidDocumentFilter)
+            }
+            e => e.into(),
+        })?
     } else {
         index.documents_ids(&rtxn)?
     };

meilisearch/src/routes/tasks.rs

@@ -99,7 +99,7 @@ pub struct DetailsView {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub deleted_tasks: Option<Option<u64>>,
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub original_filter: Option<String>,
+    pub original_filter: Option<Option<String>>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub dump_uid: Option<Option<String>>,
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -131,12 +131,13 @@ impl From<Details> for DetailsView {
             } => DetailsView {
                 provided_ids: Some(received_document_ids),
                 deleted_documents: Some(deleted_documents),
+                original_filter: Some(None),
                 ..DetailsView::default()
             },
             Details::DocumentDeletionByFilter { original_filter, deleted_documents } => {
                 DetailsView {
                     provided_ids: Some(0),
-                    original_filter: Some(original_filter),
+                    original_filter: Some(Some(original_filter)),
                     deleted_documents: Some(deleted_documents),
                     ..DetailsView::default()
                 }
@@ -148,7 +149,7 @@ impl From<Details> for DetailsView {
                 DetailsView {
                     matched_tasks: Some(matched_tasks),
                     canceled_tasks: Some(canceled_tasks),
-                    original_filter: Some(original_filter),
+                    original_filter: Some(Some(original_filter)),
                     ..DetailsView::default()
                 }
             }
@@ -156,7 +157,7 @@ impl From<Details> for DetailsView {
                 DetailsView {
                     matched_tasks: Some(matched_tasks),
                     deleted_tasks: Some(deleted_tasks),
-                    original_filter: Some(original_filter),
+                    original_filter: Some(Some(original_filter)),
                     ..DetailsView::default()
                 }
             }
@@ -729,7 +730,7 @@ mod tests {
             let err = deserr_query_params::<TaskDeletionOrCancelationQuery>(params).unwrap_err();
             snapshot!(meili_snap::json_string!(err), @r###"
             {
-              "message": "Invalid value in parameter `types`: `createIndex` is not a valid task type. Available types are `documentAdditionOrUpdate`, `documentDeletion`, `documentDeletionByFilter`, `settingsUpdate`, `indexCreation`, `indexDeletion`, `indexUpdate`, `indexSwap`, `taskCancelation`, `taskDeletion`, `dumpCreation`, `snapshotCreation`.",
+              "message": "Invalid value in parameter `types`: `createIndex` is not a valid task type. Available types are `documentAdditionOrUpdate`, `documentDeletion`, `settingsUpdate`, `indexCreation`, `indexDeletion`, `indexUpdate`, `indexSwap`, `taskCancelation`, `taskDeletion`, `dumpCreation`, `snapshotCreation`.",
               "code": "invalid_task_types",
               "type": "invalid_request",
               "link": "https://docs.meilisearch.com/errors#invalid_task_types"

meilisearch/tests/auth/authorization.rs

@@ -16,8 +16,11 @@ pub static AUTHORIZATIONS: Lazy<HashMap<(&'static str, &'static str), HashSet<&'
             ("GET",     "/indexes/products/search") =>                         hashset!{"search", "*"},
             ("POST",    "/indexes/products/documents") =>                      hashset!{"documents.add", "documents.*", "*"},
             ("GET",     "/indexes/products/documents") =>                      hashset!{"documents.get", "documents.*", "*"},
+            ("POST",    "/indexes/products/documents/fetch") =>                hashset!{"documents.get", "documents.*", "*"},
             ("GET",     "/indexes/products/documents/0") =>                    hashset!{"documents.get", "documents.*", "*"},
             ("DELETE",  "/indexes/products/documents/0") =>                    hashset!{"documents.delete", "documents.*", "*"},
+            ("POST",    "/indexes/products/documents/delete-batch") =>         hashset!{"documents.delete", "documents.*", "*"},
+            ("POST",    "/indexes/products/documents/delete") =>               hashset!{"documents.delete", "documents.*", "*"},
             ("GET",     "/tasks") =>                                           hashset!{"tasks.get", "tasks.*", "*"},
             ("DELETE",  "/tasks") =>                                           hashset!{"tasks.delete", "tasks.*", "*"},
             ("GET",     "/tasks?indexUid=products") =>                         hashset!{"tasks.get", "tasks.*", "*"},

meilisearch/tests/documents/add_documents.rs

@@ -1781,7 +1781,7 @@ async fn error_add_documents_payload_size() {
     snapshot!(json_string!(response, { ".duration" => "[duration]", ".enqueuedAt" => "[date]", ".startedAt" => "[date]", ".finishedAt" => "[date]" }),
         @r###"
     {
-      "message": "The provided payload reached the size limit.",
+      "message": "The provided payload reached the size limit. The maximum accepted payload size is 10.00 MiB.",
       "code": "payload_too_large",
       "type": "invalid_request",
       "link": "https://docs.meilisearch.com/errors#payload_too_large"

meilisearch/tests/documents/errors.rs

@@ -180,9 +180,9 @@ async fn get_all_documents_bad_filter() {
     snapshot!(json_string!(response), @r###"
     {
       "message": "Attribute `doggo` is not filterable. This index does not have configured filterable attributes.\n1:6 doggo=bernese",
-      "code": "invalid_search_filter",
+      "code": "invalid_document_filter",
       "type": "invalid_request",
-      "link": "https://docs.meilisearch.com/errors#invalid_search_filter"
+      "link": "https://docs.meilisearch.com/errors#invalid_document_filter"
     }
     "###);
 }
@@ -547,9 +547,9 @@ async fn delete_document_by_filter() {
     snapshot!(json_string!(response), @r###"
     {
       "message": "Invalid syntax for the filter parameter: `expected String, Array, found: true`.",
-      "code": "invalid_document_delete_filter",
+      "code": "invalid_document_filter",
       "type": "invalid_request",
-      "link": "https://docs.meilisearch.com/errors#invalid_document_delete_filter"
+      "link": "https://docs.meilisearch.com/errors#invalid_document_filter"
     }
     "###);
 
@@ -559,9 +559,9 @@ async fn delete_document_by_filter() {
     snapshot!(json_string!(response), @r###"
     {
       "message": "Was expecting an operation `=`, `!=`, `>=`, `>`, `<=`, `<`, `IN`, `NOT IN`, `TO`, `EXISTS`, `NOT EXISTS`, `IS NULL`, `IS NOT NULL`, `IS EMPTY`, `IS NOT EMPTY`, `_geoRadius`, or `_geoBoundingBox` at `hello`.\n1:6 hello",
-      "code": "invalid_document_delete_filter",
+      "code": "invalid_document_filter",
       "type": "invalid_request",
-      "link": "https://docs.meilisearch.com/errors#invalid_document_delete_filter"
+      "link": "https://docs.meilisearch.com/errors#invalid_document_filter"
     }
     "###);
 
@@ -571,9 +571,21 @@ async fn delete_document_by_filter() {
     snapshot!(json_string!(response), @r###"
     {
       "message": "Sending an empty filter is forbidden.",
-      "code": "invalid_document_delete_filter",
+      "code": "invalid_document_filter",
       "type": "invalid_request",
-      "link": "https://docs.meilisearch.com/errors#invalid_document_delete_filter"
+      "link": "https://docs.meilisearch.com/errors#invalid_document_filter"
+    }
+    "###);
+
+    // do not send any filter
+    let (response, code) = index.delete_document_by_filter(json!({})).await;
+    snapshot!(code, @"400 Bad Request");
+    snapshot!(json_string!(response), @r###"
+    {
+      "message": "Missing field `filter`",
+      "code": "missing_document_filter",
+      "type": "invalid_request",
+      "link": "https://docs.meilisearch.com/errors#missing_document_filter"
     }
     "###);
 
@@ -630,9 +642,9 @@ async fn delete_document_by_filter() {
       },
       "error": {
         "message": "Attribute `doggo` is not filterable. This index does not have configured filterable attributes.\n1:6 doggo = bernese",
-        "code": "invalid_search_filter",
+        "code": "invalid_document_filter",
         "type": "invalid_request",
-        "link": "https://docs.meilisearch.com/errors#invalid_search_filter"
+        "link": "https://docs.meilisearch.com/errors#invalid_document_filter"
       },
       "duration": "[duration]",
       "enqueuedAt": "[date]",
@@ -664,9 +676,9 @@ async fn delete_document_by_filter() {
       },
       "error": {
         "message": "Attribute `catto` is not filterable. Available filterable attributes are: `doggo`.\n1:6 catto = jorts",
-        "code": "invalid_search_filter",
+        "code": "invalid_document_filter",
         "type": "invalid_request",
-        "link": "https://docs.meilisearch.com/errors#invalid_search_filter"
+        "link": "https://docs.meilisearch.com/errors#invalid_document_filter"
       },
       "duration": "[duration]",
       "enqueuedAt": "[date]",
@@ -748,4 +760,27 @@ async fn fetch_document_by_filter() {
       "link": "https://docs.meilisearch.com/errors#invalid_document_filter"
     }
     "###);
+
+    let (response, code) = index.get_document_by_filter(json!({ "filter": "cool doggo" })).await;
+    snapshot!(code, @"400 Bad Request");
+    snapshot!(json_string!(response), @r###"
+    {
+      "message": "Was expecting an operation `=`, `!=`, `>=`, `>`, `<=`, `<`, `IN`, `NOT IN`, `TO`, `EXISTS`, `NOT EXISTS`, `IS NULL`, `IS NOT NULL`, `IS EMPTY`, `IS NOT EMPTY`, `_geoRadius`, or `_geoBoundingBox` at `cool doggo`.\n1:11 cool doggo",
+      "code": "invalid_document_filter",
+      "type": "invalid_request",
+      "link": "https://docs.meilisearch.com/errors#invalid_document_filter"
+    }
+    "###);
+
+    let (response, code) =
+        index.get_document_by_filter(json!({ "filter": "doggo = bernese" })).await;
+    snapshot!(code, @"400 Bad Request");
+    snapshot!(json_string!(response), @r###"
+    {
+      "message": "Attribute `doggo` is not filterable. Available filterable attributes are: `color`.\n1:6 doggo = bernese",
+      "code": "invalid_document_filter",
+      "type": "invalid_request",
+      "link": "https://docs.meilisearch.com/errors#invalid_document_filter"
+    }
+    "###);
 }

meilisearch/tests/search/errors.rs

@@ -946,7 +946,7 @@ async fn sort_unset_ranking_rule() {
     index.wait_task(1).await;
 
     let expected_response = json!({
-        "message": "The sort ranking rule must be specified in the ranking rules settings to use the sort parameter at search time.",
+        "message": "You must specify where `sort` is listed in the rankingRules setting to use the sort parameter at search time.",
         "code": "invalid_search_sort",
         "type": "invalid_request",
         "link": "https://docs.meilisearch.com/errors#invalid_search_sort"

meilisearch/tests/tasks/errors.rs

@@ -97,7 +97,7 @@ async fn task_bad_types() {
     snapshot!(code, @"400 Bad Request");
     snapshot!(json_string!(response), @r###"
     {
-      "message": "Invalid value in parameter `types`: `doggo` is not a valid task type. Available types are `documentAdditionOrUpdate`, `documentDeletion`, `documentDeletionByFilter`, `settingsUpdate`, `indexCreation`, `indexDeletion`, `indexUpdate`, `indexSwap`, `taskCancelation`, `taskDeletion`, `dumpCreation`, `snapshotCreation`.",
+      "message": "Invalid value in parameter `types`: `doggo` is not a valid task type. Available types are `documentAdditionOrUpdate`, `documentDeletion`, `settingsUpdate`, `indexCreation`, `indexDeletion`, `indexUpdate`, `indexSwap`, `taskCancelation`, `taskDeletion`, `dumpCreation`, `snapshotCreation`.",
       "code": "invalid_task_types",
       "type": "invalid_request",
       "link": "https://docs.meilisearch.com/errors#invalid_task_types"
@@ -108,7 +108,7 @@ async fn task_bad_types() {
     snapshot!(code, @"400 Bad Request");
     snapshot!(json_string!(response), @r###"
     {
-      "message": "Invalid value in parameter `types`: `doggo` is not a valid task type. Available types are `documentAdditionOrUpdate`, `documentDeletion`, `documentDeletionByFilter`, `settingsUpdate`, `indexCreation`, `indexDeletion`, `indexUpdate`, `indexSwap`, `taskCancelation`, `taskDeletion`, `dumpCreation`, `snapshotCreation`.",
+      "message": "Invalid value in parameter `types`: `doggo` is not a valid task type. Available types are `documentAdditionOrUpdate`, `documentDeletion`, `settingsUpdate`, `indexCreation`, `indexDeletion`, `indexUpdate`, `indexSwap`, `taskCancelation`, `taskDeletion`, `dumpCreation`, `snapshotCreation`.",
       "code": "invalid_task_types",
       "type": "invalid_request",
       "link": "https://docs.meilisearch.com/errors#invalid_task_types"
@@ -119,7 +119,7 @@ async fn task_bad_types() {
     snapshot!(code, @"400 Bad Request");
     snapshot!(json_string!(response), @r###"
     {
-      "message": "Invalid value in parameter `types`: `doggo` is not a valid task type. Available types are `documentAdditionOrUpdate`, `documentDeletion`, `documentDeletionByFilter`, `settingsUpdate`, `indexCreation`, `indexDeletion`, `indexUpdate`, `indexSwap`, `taskCancelation`, `taskDeletion`, `dumpCreation`, `snapshotCreation`.",
+      "message": "Invalid value in parameter `types`: `doggo` is not a valid task type. Available types are `documentAdditionOrUpdate`, `documentDeletion`, `settingsUpdate`, `indexCreation`, `indexDeletion`, `indexUpdate`, `indexSwap`, `taskCancelation`, `taskDeletion`, `dumpCreation`, `snapshotCreation`.",
       "code": "invalid_task_types",
       "type": "invalid_request",
       "link": "https://docs.meilisearch.com/errors#invalid_task_types"

meilisearch/tests/tasks/mod.rs

@@ -413,7 +413,7 @@ async fn test_summarized_document_addition_or_update() {
 }
 
 #[actix_web::test]
-async fn test_summarized_delete_batch() {
+async fn test_summarized_delete_documents_by_batch() {
     let server = Server::new().await;
     let index = server.index("test");
     index.delete_batch(vec![1, 2, 3]).await;
@@ -430,7 +430,8 @@ async fn test_summarized_delete_batch() {
       "canceledBy": null,
       "details": {
         "providedIds": 3,
-        "deletedDocuments": 0
+        "deletedDocuments": 0,
+        "originalFilter": null
       },
       "error": {
         "message": "Index `test` not found.",
@@ -460,7 +461,8 @@ async fn test_summarized_delete_batch() {
       "canceledBy": null,
       "details": {
         "providedIds": 1,
-        "deletedDocuments": 0
+        "deletedDocuments": 0,
+        "originalFilter": null
       },
       "error": null,
       "duration": "[duration]",
@@ -472,7 +474,100 @@ async fn test_summarized_delete_batch() {
 }
 
 #[actix_web::test]
-async fn test_summarized_delete_document() {
+async fn test_summarized_delete_documents_by_filter() {
+    let server = Server::new().await;
+    let index = server.index("test");
+
+    index.delete_document_by_filter(json!({ "filter": "doggo = bernese" })).await;
+    index.wait_task(0).await;
+    let (task, _) = index.get_task(0).await;
+    assert_json_snapshot!(task,
+        { ".duration" => "[duration]", ".enqueuedAt" => "[date]", ".startedAt" => "[date]", ".finishedAt" => "[date]" },
+        @r###"
+    {
+      "uid": 0,
+      "indexUid": "test",
+      "status": "failed",
+      "type": "documentDeletion",
+      "canceledBy": null,
+      "details": {
+        "providedIds": 0,
+        "deletedDocuments": 0,
+        "originalFilter": "\"doggo = bernese\""
+      },
+      "error": {
+        "message": "Index `test` not found.",
+        "code": "index_not_found",
+        "type": "invalid_request",
+        "link": "https://docs.meilisearch.com/errors#index_not_found"
+      },
+      "duration": "[duration]",
+      "enqueuedAt": "[date]",
+      "startedAt": "[date]",
+      "finishedAt": "[date]"
+    }
+    "###);
+
+    index.create(None).await;
+    index.delete_document_by_filter(json!({ "filter": "doggo = bernese" })).await;
+    index.wait_task(2).await;
+    let (task, _) = index.get_task(2).await;
+    assert_json_snapshot!(task,
+        { ".duration" => "[duration]", ".enqueuedAt" => "[date]", ".startedAt" => "[date]", ".finishedAt" => "[date]" },
+        @r###"
+    {
+      "uid": 2,
+      "indexUid": "test",
+      "status": "failed",
+      "type": "documentDeletion",
+      "canceledBy": null,
+      "details": {
+        "providedIds": 0,
+        "deletedDocuments": 0,
+        "originalFilter": "\"doggo = bernese\""
+      },
+      "error": {
+        "message": "Attribute `doggo` is not filterable. This index does not have configured filterable attributes.\n1:6 doggo = bernese",
+        "code": "invalid_document_filter",
+        "type": "invalid_request",
+        "link": "https://docs.meilisearch.com/errors#invalid_document_filter"
+      },
+      "duration": "[duration]",
+      "enqueuedAt": "[date]",
+      "startedAt": "[date]",
+      "finishedAt": "[date]"
+    }
+    "###);
+
+    index.update_settings(json!({ "filterableAttributes": ["doggo"] })).await;
+    index.delete_document_by_filter(json!({ "filter": "doggo = bernese" })).await;
+    index.wait_task(4).await;
+    let (task, _) = index.get_task(4).await;
+    assert_json_snapshot!(task,
+        { ".duration" => "[duration]", ".enqueuedAt" => "[date]", ".startedAt" => "[date]", ".finishedAt" => "[date]" },
+        @r###"
+    {
+      "uid": 4,
+      "indexUid": "test",
+      "status": "succeeded",
+      "type": "documentDeletion",
+      "canceledBy": null,
+      "details": {
+        "providedIds": 0,
+        "deletedDocuments": 0,
+        "originalFilter": "\"doggo = bernese\""
+      },
+      "error": null,
+      "duration": "[duration]",
+      "enqueuedAt": "[date]",
+      "startedAt": "[date]",
+      "finishedAt": "[date]"
+    }
+    "###);
+}
+
+#[actix_web::test]
+async fn test_summarized_delete_document_by_id() {
     let server = Server::new().await;
     let index = server.index("test");
     index.delete_document(1).await;
@@ -489,7 +584,8 @@ async fn test_summarized_delete_document() {
       "canceledBy": null,
       "details": {
         "providedIds": 1,
-        "deletedDocuments": 0
+        "deletedDocuments": 0,
+        "originalFilter": null
       },
       "error": {
         "message": "Index `test` not found.",
@@ -519,7 +615,8 @@ async fn test_summarized_delete_document() {
       "canceledBy": null,
       "details": {
         "providedIds": 1,
-        "deletedDocuments": 0
+        "deletedDocuments": 0,
+        "originalFilter": null
       },
       "error": null,
       "duration": "[duration]",

milli/Cargo.toml

@@ -25,8 +25,13 @@ flatten-serde-json = { path = "../flatten-serde-json" }
 fst = "0.4.7"
 fxhash = "0.2.1"
 geoutils = "0.5.1"
-grenad = { version = "0.4.4", default-features = false, features = ["tempfile"] }
+grenad = { version = "0.4.4", default-features = false, features = [
-heed = { git = "https://github.com/meilisearch/heed", tag = "v0.12.5", default-features = false, features = ["lmdb", "sync-read-txn"] }
+    "tempfile",
+] }
+heed = { git = "https://github.com/meilisearch/heed", tag = "v0.12.6", default-features = false, features = [
+    "lmdb",
+    "sync-read-txn",
+] }
 json-depth-checker = { path = "../json-depth-checker" }
 levenshtein_automata = { version = "0.2.1", features = ["fst_automaton"] }
 memmap2 = "0.5.10"
@@ -44,7 +49,12 @@ smallvec = "1.10.0"
 smartstring = "1.0.1"
 tempfile = "3.5.0"
 thiserror = "1.0.40"
-time = { version = "0.3.20", features = ["serde-well-known", "formatting", "parsing", "macros"] }
+time = { version = "0.3.20", features = [
+    "serde-well-known",
+    "formatting",
+    "parsing",
+    "macros",
+] }
 uuid = { version = "1.3.1", features = ["v4"] }
 
 filter-parser = { path = "../filter-parser" }

milli/src/error.rs

@@ -126,7 +126,7 @@ only composed of alphanumeric characters (a-z A-Z 0-9), hyphens (-) and undersco
     InvalidSortableAttribute { field: String, valid_fields: BTreeSet<String> },
     #[error("{}", HeedError::BadOpenOptions)]
     InvalidLmdbOpenOptions,
-    #[error("The sort ranking rule must be specified in the ranking rules settings to use the sort parameter at search time.")]
+    #[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.")]
     InvalidStoreFile,

milli/src/index.rs

@@ -170,33 +170,46 @@ impl Index {
         unsafe { options.flag(Flags::MdbAlwaysFreePages) };
 
         let env = options.open(path)?;
-        let main = env.create_poly_database(Some(MAIN))?;
+        let mut wtxn = env.write_txn()?;
-        let word_docids = env.create_database(Some(WORD_DOCIDS))?;
+        let main = env.create_poly_database(&mut wtxn, Some(MAIN))?;
-        let exact_word_docids = env.create_database(Some(EXACT_WORD_DOCIDS))?;
+        let word_docids = env.create_database(&mut wtxn, Some(WORD_DOCIDS))?;
-        let word_prefix_docids = env.create_database(Some(WORD_PREFIX_DOCIDS))?;
+        let exact_word_docids = env.create_database(&mut wtxn, Some(EXACT_WORD_DOCIDS))?;
-        let exact_word_prefix_docids = env.create_database(Some(EXACT_WORD_PREFIX_DOCIDS))?;
+        let word_prefix_docids = env.create_database(&mut wtxn, Some(WORD_PREFIX_DOCIDS))?;
-        let docid_word_positions = env.create_database(Some(DOCID_WORD_POSITIONS))?;
+        let exact_word_prefix_docids =
-        let word_pair_proximity_docids = env.create_database(Some(WORD_PAIR_PROXIMITY_DOCIDS))?;
+            env.create_database(&mut wtxn, Some(EXACT_WORD_PREFIX_DOCIDS))?;
-        let script_language_docids = env.create_database(Some(SCRIPT_LANGUAGE_DOCIDS))?;
+        let docid_word_positions = env.create_database(&mut wtxn, Some(DOCID_WORD_POSITIONS))?;
+        let word_pair_proximity_docids =
+            env.create_database(&mut wtxn, Some(WORD_PAIR_PROXIMITY_DOCIDS))?;
+        let script_language_docids =
+            env.create_database(&mut wtxn, Some(SCRIPT_LANGUAGE_DOCIDS))?;
         let word_prefix_pair_proximity_docids =
-            env.create_database(Some(WORD_PREFIX_PAIR_PROXIMITY_DOCIDS))?;
+            env.create_database(&mut wtxn, Some(WORD_PREFIX_PAIR_PROXIMITY_DOCIDS))?;
         let prefix_word_pair_proximity_docids =
-            env.create_database(Some(PREFIX_WORD_PAIR_PROXIMITY_DOCIDS))?;
+            env.create_database(&mut wtxn, Some(PREFIX_WORD_PAIR_PROXIMITY_DOCIDS))?;
-        let word_position_docids = env.create_database(Some(WORD_POSITION_DOCIDS))?;
+        let word_position_docids = env.create_database(&mut wtxn, Some(WORD_POSITION_DOCIDS))?;
-        let word_fid_docids = env.create_database(Some(WORD_FIELD_ID_DOCIDS))?;
+        let word_fid_docids = env.create_database(&mut wtxn, Some(WORD_FIELD_ID_DOCIDS))?;
-        let field_id_word_count_docids = env.create_database(Some(FIELD_ID_WORD_COUNT_DOCIDS))?;
+        let field_id_word_count_docids =
-        let word_prefix_position_docids = env.create_database(Some(WORD_PREFIX_POSITION_DOCIDS))?;
+            env.create_database(&mut wtxn, Some(FIELD_ID_WORD_COUNT_DOCIDS))?;
-        let word_prefix_fid_docids = env.create_database(Some(WORD_PREFIX_FIELD_ID_DOCIDS))?;
+        let word_prefix_position_docids =
-        let facet_id_f64_docids = env.create_database(Some(FACET_ID_F64_DOCIDS))?;
+            env.create_database(&mut wtxn, Some(WORD_PREFIX_POSITION_DOCIDS))?;
-        let facet_id_string_docids = env.create_database(Some(FACET_ID_STRING_DOCIDS))?;
+        let word_prefix_fid_docids =
-        let facet_id_exists_docids = env.create_database(Some(FACET_ID_EXISTS_DOCIDS))?;
+            env.create_database(&mut wtxn, Some(WORD_PREFIX_FIELD_ID_DOCIDS))?;
-        let facet_id_is_null_docids = env.create_database(Some(FACET_ID_IS_NULL_DOCIDS))?;
+        let facet_id_f64_docids = env.create_database(&mut wtxn, Some(FACET_ID_F64_DOCIDS))?;
-        let facet_id_is_empty_docids = env.create_database(Some(FACET_ID_IS_EMPTY_DOCIDS))?;
+        let facet_id_string_docids =
+            env.create_database(&mut wtxn, Some(FACET_ID_STRING_DOCIDS))?;
+        let facet_id_exists_docids =
+            env.create_database(&mut wtxn, Some(FACET_ID_EXISTS_DOCIDS))?;
+        let facet_id_is_null_docids =
+            env.create_database(&mut wtxn, Some(FACET_ID_IS_NULL_DOCIDS))?;
+        let facet_id_is_empty_docids =
+            env.create_database(&mut wtxn, Some(FACET_ID_IS_EMPTY_DOCIDS))?;
 
-        let field_id_docid_facet_f64s = env.create_database(Some(FIELD_ID_DOCID_FACET_F64S))?;
+        let field_id_docid_facet_f64s =
+            env.create_database(&mut wtxn, Some(FIELD_ID_DOCID_FACET_F64S))?;
         let field_id_docid_facet_strings =
-            env.create_database(Some(FIELD_ID_DOCID_FACET_STRINGS))?;
+            env.create_database(&mut wtxn, Some(FIELD_ID_DOCID_FACET_STRINGS))?;
-        let documents = env.create_database(Some(DOCUMENTS))?;
+        let documents = env.create_database(&mut wtxn, Some(DOCUMENTS))?;
+        wtxn.commit()?;
 
         Index::set_creation_dates(&env, main, created_at, updated_at)?;
 

milli/src/search/new/graph_based_ranking_rule.rs

@@ -46,7 +46,7 @@ use super::logger::SearchLogger;
 use super::query_graph::QueryNode;
 use super::ranking_rule_graph::{
     ConditionDocIdsCache, DeadEndsCache, ExactnessGraph, FidGraph, PositionGraph, ProximityGraph,
-    RankingRuleGraph, RankingRuleGraphTrait, TypoGraph,
+    RankingRuleGraph, RankingRuleGraphTrait, TypoGraph, WordsGraph,
 };
 use super::small_bitmap::SmallBitmap;
 use super::{QueryGraph, RankingRule, RankingRuleOutput, SearchContext};
@@ -54,6 +54,12 @@ use crate::search::new::query_term::LocatedQueryTermSubset;
 use crate::search::new::ranking_rule_graph::PathVisitor;
 use crate::{Result, TermsMatchingStrategy};
 
+pub type Words = GraphBasedRankingRule<WordsGraph>;
+impl GraphBasedRankingRule<WordsGraph> {
+    pub fn new(terms_matching_strategy: TermsMatchingStrategy) -> Self {
+        Self::new_with_id("words".to_owned(), Some(terms_matching_strategy))
+    }
+}
 pub type Proximity = GraphBasedRankingRule<ProximityGraph>;
 impl GraphBasedRankingRule<ProximityGraph> {
     pub fn new(terms_matching_strategy: Option<TermsMatchingStrategy>) -> Self {

milli/src/search/new/logger/visual.rs

@@ -4,7 +4,6 @@ use std::io::{BufWriter, Write};
 use std::path::{Path, PathBuf};
 use std::time::Instant;
 
-// use rand::random;
 use roaring::RoaringBitmap;
 
 use crate::search::new::interner::Interned;
@@ -13,6 +12,7 @@ use crate::search::new::query_term::LocatedQueryTermSubset;
 use crate::search::new::ranking_rule_graph::{
     Edge, FidCondition, FidGraph, PositionCondition, PositionGraph, ProximityCondition,
     ProximityGraph, RankingRuleGraph, RankingRuleGraphTrait, TypoCondition, TypoGraph,
+    WordsCondition, WordsGraph,
 };
 use crate::search::new::ranking_rules::BoxRankingRule;
 use crate::search::new::{QueryGraph, QueryNode, RankingRule, SearchContext, SearchLogger};
@@ -24,11 +24,12 @@ pub enum SearchEvents {
     RankingRuleSkipBucket { ranking_rule_idx: usize, bucket_len: u64 },
     RankingRuleEndIteration { ranking_rule_idx: usize, universe_len: u64 },
     ExtendResults { new: Vec<u32> },
-    WordsGraph { query_graph: QueryGraph },
     ProximityGraph { graph: RankingRuleGraph<ProximityGraph> },
     ProximityPaths { paths: Vec<Vec<Interned<ProximityCondition>>> },
     TypoGraph { graph: RankingRuleGraph<TypoGraph> },
     TypoPaths { paths: Vec<Vec<Interned<TypoCondition>>> },
+    WordsGraph { graph: RankingRuleGraph<WordsGraph> },
+    WordsPaths { paths: Vec<Vec<Interned<WordsCondition>>> },
     FidGraph { graph: RankingRuleGraph<FidGraph> },
     FidPaths { paths: Vec<Vec<Interned<FidCondition>>> },
     PositionGraph { graph: RankingRuleGraph<PositionGraph> },
@@ -139,8 +140,11 @@ impl SearchLogger<QueryGraph> for VisualSearchLogger {
         let Some(location) = self.location.last() else { return };
         match location {
             Location::Words => {
-                if let Some(query_graph) = state.downcast_ref::<QueryGraph>() {
+                if let Some(graph) = state.downcast_ref::<RankingRuleGraph<WordsGraph>>() {
-                    self.events.push(SearchEvents::WordsGraph { query_graph: query_graph.clone() });
+                    self.events.push(SearchEvents::WordsGraph { graph: graph.clone() });
+                }
+                if let Some(paths) = state.downcast_ref::<Vec<Vec<Interned<WordsCondition>>>>() {
+                    self.events.push(SearchEvents::WordsPaths { paths: paths.clone() });
                 }
             }
             Location::Typo => {
@@ -329,7 +333,6 @@ impl<'ctx> DetailedLoggerFinish<'ctx> {
             SearchEvents::ExtendResults { new } => {
                 self.write_extend_results(new)?;
             }
-            SearchEvents::WordsGraph { query_graph } => self.write_words_graph(query_graph)?,
             SearchEvents::ProximityGraph { graph } => self.write_rr_graph(&graph)?,
             SearchEvents::ProximityPaths { paths } => {
                 self.write_rr_graph_paths::<ProximityGraph>(paths)?;
@@ -338,6 +341,10 @@ impl<'ctx> DetailedLoggerFinish<'ctx> {
             SearchEvents::TypoPaths { paths } => {
                 self.write_rr_graph_paths::<TypoGraph>(paths)?;
             }
+            SearchEvents::WordsGraph { graph } => self.write_rr_graph(&graph)?,
+            SearchEvents::WordsPaths { paths } => {
+                self.write_rr_graph_paths::<WordsGraph>(paths)?;
+            }
             SearchEvents::FidGraph { graph } => self.write_rr_graph(&graph)?,
             SearchEvents::FidPaths { paths } => {
                 self.write_rr_graph_paths::<FidGraph>(paths)?;
@@ -455,7 +462,7 @@ fill: \"#B6E2D3\"
                 shape: class
                 max_nbr_typo: {}",
                     term_subset.description(ctx),
-                    term_subset.max_nbr_typos(ctx)
+                    term_subset.max_typo_cost(ctx)
                 )?;
 
                 for w in term_subset.all_single_words_except_prefix_db(ctx)? {
@@ -482,13 +489,6 @@ fill: \"#B6E2D3\"
         }
         Ok(())
     }
-    fn write_words_graph(&mut self, qg: QueryGraph) -> Result<()> {
-        self.make_new_file_for_internal_state_if_needed()?;
-
-        self.write_query_graph(&qg)?;
-
-        Ok(())
-    }
     fn write_rr_graph<R: RankingRuleGraphTrait>(
         &mut self,
         graph: &RankingRuleGraph<R>,

milli/src/search/new/mod.rs

@@ -15,11 +15,7 @@ mod resolve_query_graph;
 mod small_bitmap;
 
 mod exact_attribute;
-// TODO: documentation + comments
-// implementation is currently an adaptation of the previous implementation to fit with the new model
 mod sort;
-// TODO: documentation + comments
-mod words;
 
 #[cfg(test)]
 mod tests;
@@ -43,10 +39,10 @@ use ranking_rules::{
 use resolve_query_graph::{compute_query_graph_docids, PhraseDocIdsCache};
 use roaring::RoaringBitmap;
 use sort::Sort;
-use words::Words;
 
 use self::geo_sort::GeoSort;
 pub use self::geo_sort::Strategy as GeoSortStrategy;
+use self::graph_based_ranking_rule::Words;
 use self::interner::Interned;
 use crate::search::new::distinct::apply_distinct_rule;
 use crate::{AscDesc, DocumentId, Filter, Index, Member, Result, TermsMatchingStrategy, UserError};
@@ -202,6 +198,11 @@ fn get_ranking_rules_for_query_graph_search<'ctx>(
     let mut sorted_fields = HashSet::new();
     let mut geo_sorted = false;
 
+    // Don't add the `words` ranking rule if the term matching strategy is `All`
+    if matches!(terms_matching_strategy, TermsMatchingStrategy::All) {
+        words = true;
+    }
+
     let mut ranking_rules: Vec<BoxRankingRule<QueryGraph>> = vec![];
     let settings_ranking_rules = ctx.index.criteria(ctx.txn)?;
     for rr in settings_ranking_rules {
@@ -397,8 +398,8 @@ pub fn execute_search(
         None
     };
     let bucket_sort_output = if let Some(query_terms) = query_terms {
-        let graph = QueryGraph::from_query(ctx, &query_terms)?;
+        let (graph, new_located_query_terms) = QueryGraph::from_query(ctx, &query_terms)?;
-        located_query_terms = Some(query_terms);
+        located_query_terms = Some(new_located_query_terms);
 
         let ranking_rules = get_ranking_rules_for_query_graph_search(
             ctx,

milli/src/search/new/query_graph.rs

@@ -88,12 +88,15 @@ pub struct QueryGraph {
 }
 
 impl QueryGraph {
-    /// Build the query graph from the parsed user search query.
+    /// Build the query graph from the parsed user search query, return an updated list of the located query terms
+    /// which contains ngrams.
     pub fn from_query(
         ctx: &mut SearchContext,
         // NOTE: the terms here must be consecutive
         terms: &[LocatedQueryTerm],
-    ) -> Result<QueryGraph> {
+    ) -> Result<(QueryGraph, Vec<LocatedQueryTerm>)> {
+        let mut new_located_query_terms = terms.to_vec();
+
         let nbr_typos = number_of_typos_allowed(ctx)?;
 
         let mut nodes_data: Vec<QueryNodeData> = vec![QueryNodeData::Start, QueryNodeData::End];
@@ -107,10 +110,11 @@ impl QueryGraph {
         let original_terms_len = terms.len();
         for term_idx in 0..original_terms_len {
             let mut new_nodes = vec![];
+
             let new_node_idx = add_node(
                 &mut nodes_data,
                 QueryNodeData::Term(LocatedQueryTermSubset {
-                    term_subset: QueryTermSubset::full(Interned::from_raw(term_idx as u16)),
+                    term_subset: QueryTermSubset::full(terms[term_idx].value),
                     positions: terms[term_idx].positions.clone(),
                     term_ids: term_idx as u8..=term_idx as u8,
                 }),
@@ -121,6 +125,7 @@ impl QueryGraph {
                 if let Some(ngram) =
                     query_term::make_ngram(ctx, &terms[term_idx - 1..=term_idx], &nbr_typos)?
                 {
+                    new_located_query_terms.push(ngram.clone());
                     let ngram_idx = add_node(
                         &mut nodes_data,
                         QueryNodeData::Term(LocatedQueryTermSubset {
@@ -136,6 +141,7 @@ impl QueryGraph {
                 if let Some(ngram) =
                     query_term::make_ngram(ctx, &terms[term_idx - 2..=term_idx], &nbr_typos)?
                 {
+                    new_located_query_terms.push(ngram.clone());
                     let ngram_idx = add_node(
                         &mut nodes_data,
                         QueryNodeData::Term(LocatedQueryTermSubset {
@@ -167,7 +173,7 @@ impl QueryGraph {
         let mut graph = QueryGraph { root_node, end_node, nodes };
         graph.build_initial_edges();
 
-        Ok(graph)
+        Ok((graph, new_located_query_terms))
     }
 
     /// Remove the given nodes, connecting all their predecessors to all their successors.

milli/src/search/new/query_term/compute_derivations.rs

@@ -28,16 +28,14 @@ pub enum ZeroOrOneTypo {
 impl Interned<QueryTerm> {
     pub fn compute_fully_if_needed(self, ctx: &mut SearchContext) -> Result<()> {
         let s = ctx.term_interner.get_mut(self);
-        if s.max_nbr_typos == 0 {
+        if s.max_levenshtein_distance <= 1 && s.one_typo.is_uninit() {
-            s.one_typo = Lazy::Init(OneTypoTerm::default());
-            s.two_typo = Lazy::Init(TwoTypoTerm::default());
-        } else if s.max_nbr_typos == 1 && s.one_typo.is_uninit() {
             assert!(s.two_typo.is_uninit());
+            // Initialize one_typo subterm even if max_nbr_typo is 0 because of split words
             self.initialize_one_typo_subterm(ctx)?;
             let s = ctx.term_interner.get_mut(self);
             assert!(s.one_typo.is_init());
             s.two_typo = Lazy::Init(TwoTypoTerm::default());
-        } else if s.max_nbr_typos > 1 && s.two_typo.is_uninit() {
+        } else if s.max_levenshtein_distance > 1 && s.two_typo.is_uninit() {
             assert!(s.two_typo.is_uninit());
             self.initialize_one_and_two_typo_subterm(ctx)?;
             let s = ctx.term_interner.get_mut(self);
@@ -187,7 +185,7 @@ pub fn partially_initialized_term_from_word(
                 original: ctx.word_interner.insert(word.to_owned()),
                 ngram_words: None,
                 is_prefix: false,
-                max_nbr_typos: 0,
+                max_levenshtein_distance: 0,
                 zero_typo: <_>::default(),
                 one_typo: Lazy::Init(<_>::default()),
                 two_typo: Lazy::Init(<_>::default()),
@@ -258,7 +256,7 @@ pub fn partially_initialized_term_from_word(
     Ok(QueryTerm {
         original: word_interned,
         ngram_words: None,
-        max_nbr_typos: max_typo,
+        max_levenshtein_distance: max_typo,
         is_prefix,
         zero_typo,
         one_typo: Lazy::Uninit,
@@ -277,7 +275,16 @@ fn find_split_words(ctx: &mut SearchContext, word: &str) -> Result<Option<Intern
 impl Interned<QueryTerm> {
     fn initialize_one_typo_subterm(self, ctx: &mut SearchContext) -> Result<()> {
         let self_mut = ctx.term_interner.get_mut(self);
-        let QueryTerm { original, is_prefix, one_typo, .. } = self_mut;
+
+        let allows_split_words = self_mut.allows_split_words();
+        let QueryTerm {
+            original,
+            is_prefix,
+            one_typo,
+            max_levenshtein_distance: max_nbr_typos,
+            ..
+        } = self_mut;
+
         let original = *original;
         let is_prefix = *is_prefix;
         // let original_str = ctx.word_interner.get(*original).to_owned();
@@ -286,6 +293,7 @@ impl Interned<QueryTerm> {
         }
         let mut one_typo_words = BTreeSet::new();
 
+        if *max_nbr_typos > 0 {
             find_zero_one_typo_derivations(ctx, original, is_prefix, |derived_word, nbr_typos| {
                 match nbr_typos {
                     ZeroOrOneTypo::Zero => {}
@@ -299,13 +307,19 @@ impl Interned<QueryTerm> {
                 }
                 Ok(ControlFlow::Continue(()))
             })?;
+        }
+
+        let split_words = if allows_split_words {
             let original_str = ctx.word_interner.get(original).to_owned();
-        let split_words = find_split_words(ctx, original_str.as_str())?;
+            find_split_words(ctx, original_str.as_str())?
+        } else {
+            None
+        };
 
         let self_mut = ctx.term_interner.get_mut(self);
 
         // Only add the split words to the derivations if:
-        // 1. the term is not an ngram; OR
+        // 1. the term is neither an ngram nor a phrase; OR
         // 2. the term is an ngram, but the split words are different from the ngram's component words
         let split_words = if let Some((ngram_words, split_words)) =
             self_mut.ngram_words.as_ref().zip(split_words.as_ref())
@@ -327,7 +341,13 @@ impl Interned<QueryTerm> {
     }
     fn initialize_one_and_two_typo_subterm(self, ctx: &mut SearchContext) -> Result<()> {
         let self_mut = ctx.term_interner.get_mut(self);
-        let QueryTerm { original, is_prefix, two_typo, .. } = self_mut;
+        let QueryTerm {
+            original,
+            is_prefix,
+            two_typo,
+            max_levenshtein_distance: max_nbr_typos,
+            ..
+        } = self_mut;
         let original_str = ctx.word_interner.get(*original).to_owned();
         if two_typo.is_init() {
             return Ok(());
@@ -335,6 +355,7 @@ impl Interned<QueryTerm> {
         let mut one_typo_words = BTreeSet::new();
         let mut two_typo_words = BTreeSet::new();
 
+        if *max_nbr_typos > 0 {
             find_zero_one_two_typo_derivations(
                 *original,
                 *is_prefix,
@@ -363,6 +384,8 @@ impl Interned<QueryTerm> {
                     Ok(ControlFlow::Continue(()))
                 },
             )?;
+        }
+
         let split_words = find_split_words(ctx, original_str.as_str())?;
         let self_mut = ctx.term_interner.get_mut(self);
 

milli/src/search/new/query_term/mod.rs

@@ -43,7 +43,7 @@ pub struct QueryTermSubset {
 pub struct QueryTerm {
     original: Interned<String>,
     ngram_words: Option<Vec<Interned<String>>>,
-    max_nbr_typos: u8,
+    max_levenshtein_distance: u8,
     is_prefix: bool,
     zero_typo: ZeroTypoTerm,
     // May not be computed yet
@@ -342,10 +342,16 @@ impl QueryTermSubset {
         }
         None
     }
-    pub fn max_nbr_typos(&self, ctx: &SearchContext) -> u8 {
+    pub fn max_typo_cost(&self, ctx: &SearchContext) -> u8 {
         let t = ctx.term_interner.get(self.original);
-        match t.max_nbr_typos {
+        match t.max_levenshtein_distance {
-            0 => 0,
+            0 => {
+                if t.allows_split_words() {
+                    1
+                } else {
+                    0
+                }
+            }
             1 => {
                 if self.one_typo_subset.is_empty() {
                     0
@@ -438,6 +444,9 @@ impl QueryTerm {
 
         self.zero_typo.is_empty() && one_typo.is_empty() && two_typo.is_empty()
     }
+    fn allows_split_words(&self) -> bool {
+        self.zero_typo.phrase.is_none()
+    }
 }
 
 impl Interned<QueryTerm> {

milli/src/search/new/query_term/parse_query.rs

@@ -77,13 +77,9 @@ pub fn located_query_terms_from_tokens(
                 }
             }
             TokenKind::Separator(separator_kind) => {
-                match separator_kind {
+                // add penalty for hard separators
-                    SeparatorKind::Hard => {
+                if let SeparatorKind::Hard = separator_kind {
-                        position += 1;
+                    position = position.wrapping_add(1);
-                    }
-                    SeparatorKind::Soft => {
-                        position += 0;
-                    }
                 }
 
                 phrase = 'phrase: {
@@ -217,7 +213,7 @@ pub fn make_ngram(
         original: ngram_str_interned,
         ngram_words: Some(words_interned),
         is_prefix,
-        max_nbr_typos,
+        max_levenshtein_distance: max_nbr_typos,
         zero_typo: term.zero_typo,
         one_typo: Lazy::Uninit,
         two_typo: Lazy::Uninit,
@@ -271,7 +267,7 @@ impl PhraseBuilder {
                 QueryTerm {
                     original: ctx.word_interner.insert(phrase_desc),
                     ngram_words: None,
-                    max_nbr_typos: 0,
+                    max_levenshtein_distance: 0,
                     is_prefix: false,
                     zero_typo: ZeroTypoTerm {
                         phrase: Some(phrase),
@@ -288,3 +284,36 @@ impl PhraseBuilder {
         })
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use charabia::TokenizerBuilder;
+
+    use super::*;
+    use crate::index::tests::TempIndex;
+
+    fn temp_index_with_documents() -> TempIndex {
+        let temp_index = TempIndex::new();
+        temp_index
+            .add_documents(documents!([
+                { "id": 1, "name": "split this world westfali westfalia the Ŵôřlḑôle" },
+                { "id": 2, "name": "Westfália" },
+                { "id": 3, "name": "Ŵôřlḑôle" },
+            ]))
+            .unwrap();
+        temp_index
+    }
+
+    #[test]
+    fn start_with_hard_separator() -> Result<()> {
+        let tokenizer = TokenizerBuilder::new().build();
+        let tokens = tokenizer.tokenize(".");
+        let index = temp_index_with_documents();
+        let rtxn = index.read_txn()?;
+        let mut ctx = SearchContext::new(&index, &rtxn);
+        // panics with `attempt to add with overflow` before <https://github.com/meilisearch/meilisearch/issues/3785>
+        let located_query_terms = located_query_terms_from_tokens(&mut ctx, tokens, None)?;
+        assert!(located_query_terms.is_empty());
+        Ok(())
+    }
+}

milli/src/search/new/ranking_rule_graph/cheapest_paths.rs

@@ -205,18 +205,12 @@ impl<G: RankingRuleGraphTrait> VisitorState<G> {
 impl<G: RankingRuleGraphTrait> RankingRuleGraph<G> {
     pub fn find_all_costs_to_end(&self) -> MappedInterner<QueryNode, Vec<u64>> {
         let mut costs_to_end = self.query_graph.nodes.map(|_| vec![]);
-        let mut enqueued = SmallBitmap::new(self.query_graph.nodes.len());
-
-        let mut node_stack = VecDeque::new();
 
+        self.traverse_breadth_first_backward(self.query_graph.end_node, |cur_node| {
+            if cur_node == self.query_graph.end_node {
                 *costs_to_end.get_mut(self.query_graph.end_node) = vec![0];
-
+                return;
-        for prev_node in self.query_graph.nodes.get(self.query_graph.end_node).predecessors.iter() {
-            node_stack.push_back(prev_node);
-            enqueued.insert(prev_node);
             }
-
-        while let Some(cur_node) = node_stack.pop_front() {
             let mut self_costs = Vec::<u64>::new();
 
             let cur_node_edges = &self.edges_of_node.get(cur_node);
@@ -232,13 +226,7 @@ impl<G: RankingRuleGraphTrait> RankingRuleGraph<G> {
             self_costs.dedup();
 
             *costs_to_end.get_mut(cur_node) = self_costs;
-            for prev_node in self.query_graph.nodes.get(cur_node).predecessors.iter() {
+        });
-                if !enqueued.contains(prev_node) {
-                    node_stack.push_back(prev_node);
-                    enqueued.insert(prev_node);
-                }
-            }
-        }
         costs_to_end
     }
 
@@ -247,17 +235,12 @@ impl<G: RankingRuleGraphTrait> RankingRuleGraph<G> {
         node_with_removed_outgoing_conditions: Interned<QueryNode>,
         costs: &mut MappedInterner<QueryNode, Vec<u64>>,
     ) {
-        let mut enqueued = SmallBitmap::new(self.query_graph.nodes.len());
+        // Traverse the graph backward from the target node, recomputing the cost for each of its predecessors.
-        let mut node_stack = VecDeque::new();
+        // We first check that no other node is contributing the same total cost to a predecessor before removing
-
+        // the cost from the predecessor.
-        enqueued.insert(node_with_removed_outgoing_conditions);
+        self.traverse_breadth_first_backward(node_with_removed_outgoing_conditions, |cur_node| {
-        node_stack.push_back(node_with_removed_outgoing_conditions);
-
-        'main_loop: while let Some(cur_node) = node_stack.pop_front() {
             let mut costs_to_remove = FxHashSet::default();
-            for c in costs.get(cur_node) {
+            costs_to_remove.extend(costs.get(cur_node).iter().copied());
-                costs_to_remove.insert(*c);
-            }
 
             let cur_node_edges = &self.edges_of_node.get(cur_node);
             for edge_idx in cur_node_edges.iter() {
@@ -265,22 +248,75 @@ impl<G: RankingRuleGraphTrait> RankingRuleGraph<G> {
                 for cost in costs.get(edge.dest_node).iter() {
                     costs_to_remove.remove(&(*cost + edge.cost as u64));
                     if costs_to_remove.is_empty() {
-                        continue 'main_loop;
+                        return;
                     }
                 }
             }
             if costs_to_remove.is_empty() {
-                continue 'main_loop;
+                return;
             }
             let mut new_costs = BTreeSet::from_iter(costs.get(cur_node).iter().copied());
             for c in costs_to_remove {
                 new_costs.remove(&c);
             }
             *costs.get_mut(cur_node) = new_costs.into_iter().collect();
+        });
+    }
 
+    /// Traverse the graph backwards from the given node such that every time
+    /// a node is visited, we are guaranteed that all its successors either:
+    /// 1. have already been visited; OR
+    /// 2. were not reachable from the given node
+    pub fn traverse_breadth_first_backward(
+        &self,
+        from: Interned<QueryNode>,
+        mut visit: impl FnMut(Interned<QueryNode>),
+    ) {
+        let mut reachable = SmallBitmap::for_interned_values_in(&self.query_graph.nodes);
+        {
+            // go backward to get the set of all reachable nodes from the given node
+            // the nodes that are not reachable will be set as `visited`
+            let mut stack = VecDeque::new();
+            let mut enqueued = SmallBitmap::for_interned_values_in(&self.query_graph.nodes);
+            enqueued.insert(from);
+            stack.push_back(from);
+            while let Some(n) = stack.pop_front() {
+                if reachable.contains(n) {
+                    continue;
+                }
+                reachable.insert(n);
+                for prev_node in self.query_graph.nodes.get(n).predecessors.iter() {
+                    if !enqueued.contains(prev_node) && !reachable.contains(prev_node) {
+                        stack.push_back(prev_node);
+                        enqueued.insert(prev_node);
+                    }
+                }
+            }
+        };
+        let mut unreachable_or_visited =
+            SmallBitmap::for_interned_values_in(&self.query_graph.nodes);
+        for (n, _) in self.query_graph.nodes.iter() {
+            if !reachable.contains(n) {
+                unreachable_or_visited.insert(n);
+            }
+        }
+
+        let mut enqueued = SmallBitmap::for_interned_values_in(&self.query_graph.nodes);
+        let mut stack = VecDeque::new();
+
+        enqueued.insert(from);
+        stack.push_back(from);
+
+        while let Some(cur_node) = stack.pop_front() {
+            if !self.query_graph.nodes.get(cur_node).successors.is_subset(&unreachable_or_visited) {
+                stack.push_back(cur_node);
+                continue;
+            }
+            unreachable_or_visited.insert(cur_node);
+            visit(cur_node);
             for prev_node in self.query_graph.nodes.get(cur_node).predecessors.iter() {
-                if !enqueued.contains(prev_node) {
+                if !enqueued.contains(prev_node) && !unreachable_or_visited.contains(prev_node) {
-                    node_stack.push_back(prev_node);
+                    stack.push_back(prev_node);
                     enqueued.insert(prev_node);
                 }
             }

milli/src/search/new/ranking_rule_graph/mod.rs

@@ -20,6 +20,8 @@ mod position;
 mod proximity;
 /// Implementation of the `typo` ranking rule
 mod typo;
+/// Implementation of the `words` ranking rule
+mod words;
 
 use std::collections::BTreeSet;
 use std::hash::Hash;
@@ -33,6 +35,7 @@ pub use position::{PositionCondition, PositionGraph};
 pub use proximity::{ProximityCondition, ProximityGraph};
 use roaring::RoaringBitmap;
 pub use typo::{TypoCondition, TypoGraph};
+pub use words::{WordsCondition, WordsGraph};
 
 use super::interner::{DedupInterner, FixedSizeInterner, Interned, MappedInterner};
 use super::query_term::LocatedQueryTermSubset;

milli/src/search/new/ranking_rule_graph/position/mod.rs

@@ -111,23 +111,16 @@ impl RankingRuleGraphTrait for PositionGraph {
 
 fn cost_from_position(sum_positions: u32) -> u32 {
     match sum_positions {
-        0 | 1 | 2 | 3 => sum_positions,
+        0 => 0,
-        4 | 5 => 4,
+        1 => 1,
-        6 | 7 => 5,
+        2..=4 => 2,
-        8 | 9 => 6,
+        5..=7 => 3,
-        10 | 11 => 7,
+        8..=11 => 4,
-        12 | 13 => 8,
+        12..=16 => 5,
-        14 | 15 => 9,
+        17..=24 => 6,
-        16 | 17..=24 => 10,
+        25..=64 => 7,
-        25..=32 => 11,
+        65..=256 => 8,
-        33..=64 => 12,
+        257..=1024 => 9,
-        65..=128 => 13,
+        _ => 10,
-        129..=256 => 14,
-        257..=512 => 15,
-        513..=1024 => 16,
-        1025..=2048 => 17,
-        2049..=4096 => 18,
-        4097..=8192 => 19,
-        _ => 20,
     }
 }

milli/src/search/new/ranking_rule_graph/typo/mod.rs

@@ -50,7 +50,7 @@ impl RankingRuleGraphTrait for TypoGraph {
         // 3-gram -> equivalent to 2 typos
         let base_cost = if term.term_ids.len() == 1 { 0 } else { term.term_ids.len() as u32 };
 
-        for nbr_typos in 0..=term.term_subset.max_nbr_typos(ctx) {
+        for nbr_typos in 0..=term.term_subset.max_typo_cost(ctx) {
             let mut term = term.clone();
             match nbr_typos {
                 0 => {

milli/src/search/new/ranking_rule_graph/words/mod.rs

@@ -0,0 +1,49 @@
+use roaring::RoaringBitmap;
+
+use super::{ComputedCondition, RankingRuleGraphTrait};
+use crate::search::new::interner::{DedupInterner, Interned};
+use crate::search::new::query_term::LocatedQueryTermSubset;
+use crate::search::new::resolve_query_graph::compute_query_term_subset_docids;
+use crate::search::new::SearchContext;
+use crate::Result;
+
+#[derive(Clone, PartialEq, Eq, Hash)]
+pub struct WordsCondition {
+    term: LocatedQueryTermSubset,
+}
+
+pub enum WordsGraph {}
+
+impl RankingRuleGraphTrait for WordsGraph {
+    type Condition = WordsCondition;
+
+    fn resolve_condition(
+        ctx: &mut SearchContext,
+        condition: &Self::Condition,
+        universe: &RoaringBitmap,
+    ) -> Result<ComputedCondition> {
+        let WordsCondition { term, .. } = condition;
+        // maybe compute_query_term_subset_docids should accept a universe as argument
+        let mut docids = compute_query_term_subset_docids(ctx, &term.term_subset)?;
+        docids &= universe;
+
+        Ok(ComputedCondition {
+            docids,
+            universe_len: universe.len(),
+            start_term_subset: None,
+            end_term_subset: term.clone(),
+        })
+    }
+
+    fn build_edges(
+        _ctx: &mut SearchContext,
+        conditions_interner: &mut DedupInterner<Self::Condition>,
+        _from: Option<&LocatedQueryTermSubset>,
+        to_term: &LocatedQueryTermSubset,
+    ) -> Result<Vec<(u32, Interned<Self::Condition>)>> {
+        Ok(vec![(
+            to_term.term_ids.len() as u32,
+            conditions_interner.insert(WordsCondition { term: to_term.clone() }),
+        )])
+    }
+}

milli/src/search/new/tests/attribute_position.rs

@@ -138,7 +138,7 @@ fn test_attribute_position_simple() {
     s.terms_matching_strategy(TermsMatchingStrategy::All);
     s.query("quick brown");
     let SearchResult { documents_ids, .. } = s.execute().unwrap();
-    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[10, 11, 12, 13, 3, 4, 2, 1, 0, 6, 8, 7, 9, 5]");
+    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[10, 11, 12, 13, 2, 3, 4, 1, 0, 6, 8, 7, 9, 5]");
 }
 #[test]
 fn test_attribute_position_repeated() {
@@ -163,7 +163,7 @@ fn test_attribute_position_different_fields() {
     s.terms_matching_strategy(TermsMatchingStrategy::All);
     s.query("quick brown");
     let SearchResult { documents_ids, .. } = s.execute().unwrap();
-    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[10, 11, 12, 13, 3, 4, 2, 1, 0, 6, 8, 7, 9, 5]");
+    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[10, 11, 12, 13, 2, 3, 4, 1, 0, 6, 8, 7, 9, 5]");
 }
 
 #[test]
@@ -176,5 +176,5 @@ fn test_attribute_position_ngrams() {
     s.terms_matching_strategy(TermsMatchingStrategy::All);
     s.query("quick brown");
     let SearchResult { documents_ids, .. } = s.execute().unwrap();
-    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[10, 11, 12, 13, 3, 4, 2, 1, 0, 6, 8, 7, 9, 5]");
+    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[10, 11, 12, 13, 2, 3, 4, 1, 0, 6, 8, 7, 9, 5]");
 }

milli/src/search/new/tests/ngram_split_words.rs

@@ -3,9 +3,9 @@ This module tests the following properties:
 
 1. Two consecutive words from a query can be combined into a "2gram"
 2. Three consecutive words from a query can be combined into a "3gram"
-3. A word from the query can be split into two consecutive words (split words)
+3. A word from the query can be split into two consecutive words (split words), no matter how short it is
 4. A 2gram can be split into two words
-5. A 3gram cannot be split into two words
+5. A 3gram can be split into two words
 6. 2grams can contain up to 1 typo
 7. 3grams cannot have typos
 8. 2grams and 3grams can be prefix tolerant
@@ -14,6 +14,7 @@ This module tests the following properties:
 11. Disabling typo tolerance does not disable ngram tolerance
 12. Prefix tolerance is disabled for the last word if a space follows it
 13. Ngrams cannot be formed by combining a phrase and a word or two phrases
+14. Split words are not disabled by the `disableOnAttribute` or `disableOnWords` typo settings
 */
 
 use crate::index::tests::TempIndex;
@@ -56,6 +57,10 @@ fn create_index() -> TempIndex {
             {
                 "id": 5,
                 "text": "sunflowering is not a verb"
+            },
+            {
+                "id": 6,
+                "text": "xy z"
             }
         ]))
         .unwrap();
@@ -263,11 +268,12 @@ fn test_disable_split_words() {
     s.query("sunflower ");
     let SearchResult { documents_ids, .. } = s.execute().unwrap();
     // no document containing `sun flower`
-    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[3]");
+    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[1, 3]");
     let texts = collect_field_values(&index, &txn, "text", &documents_ids);
     insta::assert_debug_snapshot!(texts, @r###"
     [
         "\"the sun flower is tall\"",
+        "\"the sunflower is tall\"",
     ]
     "###);
 }
@@ -307,10 +313,11 @@ fn test_3gram_no_split_words() {
     let SearchResult { documents_ids, .. } = s.execute().unwrap();
 
     // no document with `sun flower`
-    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[2, 3, 5]");
+    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[1, 2, 3, 5]");
     let texts = collect_field_values(&index, &txn, "text", &documents_ids);
     insta::assert_debug_snapshot!(texts, @r###"
     [
+        "\"the sun flower is tall\"",
         "\"the sunflowers are pretty\"",
         "\"the sunflower is tall\"",
         "\"sunflowering is not a verb\"",
@@ -369,3 +376,50 @@ fn test_no_ngram_phrases() {
     ]
     "###);
 }
+
+#[test]
+fn test_short_split_words() {
+    let index = create_index();
+    let txn = index.read_txn().unwrap();
+
+    let mut s = Search::new(&txn, &index);
+    s.terms_matching_strategy(TermsMatchingStrategy::All);
+    s.query("xyz");
+    let SearchResult { documents_ids, .. } = s.execute().unwrap();
+
+    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[6]");
+    let texts = collect_field_values(&index, &txn, "text", &documents_ids);
+    insta::assert_debug_snapshot!(texts, @r###"
+    [
+        "\"xy z\"",
+    ]
+    "###);
+}
+
+#[test]
+fn test_split_words_never_disabled() {
+    let index = create_index();
+
+    index
+        .update_settings(|s| {
+            s.set_exact_words(["sunflower"].iter().map(ToString::to_string).collect());
+            s.set_exact_attributes(["text"].iter().map(ToString::to_string).collect());
+        })
+        .unwrap();
+
+    let txn = index.read_txn().unwrap();
+
+    let mut s = Search::new(&txn, &index);
+    s.terms_matching_strategy(TermsMatchingStrategy::All);
+    s.query("the sunflower is tall");
+    let SearchResult { documents_ids, .. } = s.execute().unwrap();
+
+    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[1, 3]");
+    let texts = collect_field_values(&index, &txn, "text", &documents_ids);
+    insta::assert_debug_snapshot!(texts, @r###"
+    [
+        "\"the sun flower is tall\"",
+        "\"the sunflower is tall\"",
+    ]
+    "###);
+}

milli/src/search/new/tests/typo.rs

@@ -9,7 +9,7 @@ This module tests the following properties:
 6. A typo on the first letter of a word counts as two typos
 7. Phrases are not typo tolerant
 8. 2grams can have 1 typo if they are larger than `min_word_len_two_typos`
-9. 3grams are not typo tolerant
+9. 3grams are not typo tolerant (but they can be split into two words)
 10. The `typo` ranking rule assumes the role of the `words` ranking rule implicitly
 if `words` doesn't exist before it.
 11. The `typo` ranking rule places documents with the same number of typos in the same bucket
@@ -287,15 +287,16 @@ fn test_typo_exact_word() {
     ]
     "###);
 
-    // exact words do not disable prefix (sunflowering OK, but no sunflowar or sun flower)
+    // exact words do not disable prefix (sunflowering OK, but no sunflowar)
     let mut s = Search::new(&txn, &index);
     s.terms_matching_strategy(TermsMatchingStrategy::All);
     s.query("network interconnection sunflower");
     let SearchResult { documents_ids, .. } = s.execute().unwrap();
-    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[16, 18]");
+    insta::assert_snapshot!(format!("{documents_ids:?}"), @"[16, 17, 18]");
     let texts = collect_field_values(&index, &txn, "text", &documents_ids);
     insta::assert_debug_snapshot!(texts, @r###"
     [
+        "\"network interconnection sunflower\"",
         "\"network interconnection sun flower\"",
         "\"network interconnection sunflowering\"",
     ]

milli/src/search/new/words.rs

@@ -1,87 +0,0 @@
-use roaring::RoaringBitmap;
-
-use super::logger::SearchLogger;
-use super::query_graph::QueryNode;
-use super::resolve_query_graph::compute_query_graph_docids;
-use super::small_bitmap::SmallBitmap;
-use super::{QueryGraph, RankingRule, RankingRuleOutput, SearchContext};
-use crate::{Result, TermsMatchingStrategy};
-
-pub struct Words {
-    exhausted: bool, // TODO: remove
-    query_graph: Option<QueryGraph>,
-    nodes_to_remove: Vec<SmallBitmap<QueryNode>>,
-    terms_matching_strategy: TermsMatchingStrategy,
-}
-impl Words {
-    pub fn new(terms_matching_strategy: TermsMatchingStrategy) -> Self {
-        Self {
-            exhausted: true,
-            query_graph: None,
-            nodes_to_remove: vec![],
-            terms_matching_strategy,
-        }
-    }
-}
-
-impl<'ctx> RankingRule<'ctx, QueryGraph> for Words {
-    fn id(&self) -> String {
-        "words".to_owned()
-    }
-    fn start_iteration(
-        &mut self,
-        ctx: &mut SearchContext<'ctx>,
-        _logger: &mut dyn SearchLogger<QueryGraph>,
-        _universe: &RoaringBitmap,
-        parent_query_graph: &QueryGraph,
-    ) -> Result<()> {
-        self.exhausted = false;
-        self.query_graph = Some(parent_query_graph.clone());
-        self.nodes_to_remove = match self.terms_matching_strategy {
-            TermsMatchingStrategy::Last => {
-                let mut ns = parent_query_graph.removal_order_for_terms_matching_strategy_last(ctx);
-                ns.reverse();
-                ns
-            }
-            TermsMatchingStrategy::All => {
-                vec![]
-            }
-        };
-        Ok(())
-    }
-
-    fn next_bucket(
-        &mut self,
-        ctx: &mut SearchContext<'ctx>,
-        logger: &mut dyn SearchLogger<QueryGraph>,
-        universe: &RoaringBitmap,
-    ) -> Result<Option<RankingRuleOutput<QueryGraph>>> {
-        if self.exhausted {
-            return Ok(None);
-        }
-        let Some(query_graph) = &mut self.query_graph else { panic!() };
-        logger.log_internal_state(query_graph);
-
-        let this_bucket = compute_query_graph_docids(ctx, query_graph, universe)?;
-
-        let child_query_graph = query_graph.clone();
-
-        if self.nodes_to_remove.is_empty() {
-            self.exhausted = true;
-        } else {
-            let nodes_to_remove = self.nodes_to_remove.pop().unwrap();
-            query_graph.remove_nodes_keep_edges(&nodes_to_remove.iter().collect::<Vec<_>>());
-        }
-        Ok(Some(RankingRuleOutput { query: child_query_graph, candidates: this_bucket }))
-    }
-
-    fn end_iteration(
-        &mut self,
-        _ctx: &mut SearchContext<'ctx>,
-        _logger: &mut dyn SearchLogger<QueryGraph>,
-    ) {
-        self.exhausted = true;
-        self.nodes_to_remove = vec![];
-        self.query_graph = None;
-    }
-}

milli/src/update/facet/mod.rs

@@ -261,7 +261,9 @@ pub(crate) mod test_helpers {
             let options = options.map_size(4096 * 4 * 1000 * 100);
             let tempdir = tempfile::TempDir::new().unwrap();
             let env = options.open(tempdir.path()).unwrap();
-            let content = env.create_database(None).unwrap();
+            let mut wtxn = env.write_txn().unwrap();
+            let content = env.create_database(&mut wtxn, None).unwrap();
+            wtxn.commit().unwrap();
 
             FacetIndex {
                 content,