Change the error codes of the faceting settings

Cargo.lock

@@ -2730,6 +2730,7 @@ dependencies = [
  "geoutils",
  "grenad",
  "heed",
+ "indexmap",
  "insta",
  "itertools",
  "json-depth-checker",

dump/src/reader/compat/v5_to_v6.rs

@@ -358,6 +358,7 @@ impl<T> From<v5::Settings<T>> for v6::Settings<v6::Unchecked> {
             faceting: match settings.faceting {
                 v5::Setting::Set(faceting) => v6::Setting::Set(v6::FacetingSettings {
                     max_values_per_facet: faceting.max_values_per_facet.into(),
+                    sort_facet_values_by: v6::Setting::NotSet,
                 }),
                 v5::Setting::Reset => v6::Setting::Reset,
                 v5::Setting::NotSet => v6::Setting::NotSet,

meilisearch-types/src/error.rs

@@ -175,120 +175,122 @@ macro_rules! make_error_codes {
 
 // An exhaustive list of all the error codes used by meilisearch.
 make_error_codes! {
-ApiKeyAlreadyExists                   , InvalidRequest       , CONFLICT ;
-ApiKeyNotFound                        , InvalidRequest       , NOT_FOUND ;
-BadParameter                          , InvalidRequest       , BAD_REQUEST;
-BadRequest                            , InvalidRequest       , BAD_REQUEST;
-DatabaseSizeLimitReached              , Internal             , INTERNAL_SERVER_ERROR;
-DocumentNotFound                      , InvalidRequest       , NOT_FOUND;
-DumpAlreadyProcessing                 , InvalidRequest       , CONFLICT;
-DumpNotFound                          , InvalidRequest       , NOT_FOUND;
-DumpProcessFailed                     , Internal             , INTERNAL_SERVER_ERROR;
-DuplicateIndexFound                   , InvalidRequest       , BAD_REQUEST;
-ImmutableApiKeyActions                , InvalidRequest       , BAD_REQUEST;
-ImmutableApiKeyCreatedAt              , InvalidRequest       , BAD_REQUEST;
-ImmutableApiKeyExpiresAt              , InvalidRequest       , BAD_REQUEST;
-ImmutableApiKeyIndexes                , InvalidRequest       , BAD_REQUEST;
-ImmutableApiKeyKey                    , InvalidRequest       , BAD_REQUEST;
-ImmutableApiKeyUid                    , InvalidRequest       , BAD_REQUEST;
-ImmutableApiKeyUpdatedAt              , InvalidRequest       , BAD_REQUEST;
-ImmutableIndexCreatedAt               , InvalidRequest       , BAD_REQUEST;
-ImmutableIndexUid                     , InvalidRequest       , BAD_REQUEST;
-ImmutableIndexUpdatedAt               , InvalidRequest       , BAD_REQUEST;
-IndexAlreadyExists                    , InvalidRequest       , CONFLICT ;
-IndexCreationFailed                   , Internal             , INTERNAL_SERVER_ERROR;
-IndexNotFound                         , InvalidRequest       , NOT_FOUND;
-IndexPrimaryKeyAlreadyExists          , InvalidRequest       , BAD_REQUEST ;
-IndexPrimaryKeyMultipleCandidatesFound, InvalidRequest       , BAD_REQUEST;
-IndexPrimaryKeyNoCandidateFound       , InvalidRequest       , BAD_REQUEST ;
-Internal                              , Internal             , INTERNAL_SERVER_ERROR ;
-InvalidApiKey                         , Auth                 , FORBIDDEN ;
-InvalidApiKeyActions                  , InvalidRequest       , BAD_REQUEST ;
-InvalidApiKeyDescription              , InvalidRequest       , BAD_REQUEST ;
-InvalidApiKeyExpiresAt                , InvalidRequest       , BAD_REQUEST ;
-InvalidApiKeyIndexes                  , InvalidRequest       , BAD_REQUEST ;
-InvalidApiKeyLimit                    , InvalidRequest       , BAD_REQUEST ;
-InvalidApiKeyName                     , InvalidRequest       , BAD_REQUEST ;
-InvalidApiKeyOffset                   , InvalidRequest       , BAD_REQUEST ;
-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 ;
-InvalidIndexLimit                     , InvalidRequest       , BAD_REQUEST ;
-InvalidIndexOffset                    , InvalidRequest       , BAD_REQUEST ;
-InvalidIndexPrimaryKey                , InvalidRequest       , BAD_REQUEST ;
-InvalidIndexUid                       , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchAttributesToCrop         , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchAttributesToHighlight    , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchAttributesToRetrieve     , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchCropLength               , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchCropMarker               , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchFacets                   , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchFilter                   , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchHighlightPostTag         , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchHighlightPreTag          , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchHitsPerPage              , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchLimit                    , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchMatchingStrategy         , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchOffset                   , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchPage                     , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchQ                        , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchShowMatchesPosition      , InvalidRequest       , BAD_REQUEST ;
-InvalidSearchSort                     , InvalidRequest       , BAD_REQUEST ;
-InvalidSettingsDisplayedAttributes    , InvalidRequest       , BAD_REQUEST ;
-InvalidSettingsDistinctAttribute      , InvalidRequest       , BAD_REQUEST ;
-InvalidSettingsFaceting               , InvalidRequest       , BAD_REQUEST ;
-InvalidSettingsFilterableAttributes   , InvalidRequest       , BAD_REQUEST ;
-InvalidSettingsPagination             , InvalidRequest       , BAD_REQUEST ;
-InvalidSettingsRankingRules           , InvalidRequest       , BAD_REQUEST ;
-InvalidSettingsSearchableAttributes   , InvalidRequest       , BAD_REQUEST ;
-InvalidSettingsSortableAttributes     , InvalidRequest       , BAD_REQUEST ;
-InvalidSettingsStopWords              , InvalidRequest       , BAD_REQUEST ;
-InvalidSettingsSynonyms               , InvalidRequest       , BAD_REQUEST ;
-InvalidSettingsTypoTolerance          , InvalidRequest       , BAD_REQUEST ;
-InvalidState                          , Internal             , INTERNAL_SERVER_ERROR ;
-InvalidStoreFile                      , Internal             , INTERNAL_SERVER_ERROR ;
-InvalidSwapDuplicateIndexFound        , InvalidRequest       , BAD_REQUEST ;
-InvalidSwapIndexes                    , InvalidRequest       , BAD_REQUEST ;
-InvalidTaskAfterEnqueuedAt            , InvalidRequest       , BAD_REQUEST ;
-InvalidTaskAfterFinishedAt            , InvalidRequest       , BAD_REQUEST ;
-InvalidTaskAfterStartedAt             , InvalidRequest       , BAD_REQUEST ;
-InvalidTaskBeforeEnqueuedAt           , InvalidRequest       , BAD_REQUEST ;
-InvalidTaskBeforeFinishedAt           , InvalidRequest       , BAD_REQUEST ;
-InvalidTaskBeforeStartedAt            , InvalidRequest       , BAD_REQUEST ;
-InvalidTaskCanceledBy                 , InvalidRequest       , BAD_REQUEST ;
-InvalidTaskFrom                       , InvalidRequest       , BAD_REQUEST ;
-InvalidTaskLimit                      , InvalidRequest       , BAD_REQUEST ;
-InvalidTaskStatuses                   , InvalidRequest       , BAD_REQUEST ;
-InvalidTaskTypes                      , InvalidRequest       , BAD_REQUEST ;
-InvalidTaskUids                       , InvalidRequest       , BAD_REQUEST  ;
-IoError                               , System               , UNPROCESSABLE_ENTITY;
-MalformedPayload                      , InvalidRequest       , BAD_REQUEST ;
-MaxFieldsLimitExceeded                , InvalidRequest       , BAD_REQUEST ;
-MissingApiKeyActions                  , InvalidRequest       , BAD_REQUEST ;
-MissingApiKeyExpiresAt                , InvalidRequest       , BAD_REQUEST ;
-MissingApiKeyIndexes                  , InvalidRequest       , BAD_REQUEST ;
-MissingAuthorizationHeader            , Auth                 , UNAUTHORIZED ;
-MissingContentType                    , InvalidRequest       , UNSUPPORTED_MEDIA_TYPE ;
-MissingDocumentId                     , InvalidRequest       , BAD_REQUEST ;
-MissingIndexUid                       , InvalidRequest       , BAD_REQUEST ;
-MissingMasterKey                      , Auth                 , UNAUTHORIZED ;
-MissingPayload                        , InvalidRequest       , BAD_REQUEST ;
-MissingSwapIndexes                    , InvalidRequest       , BAD_REQUEST ;
-MissingTaskFilters                    , InvalidRequest       , BAD_REQUEST ;
-NoSpaceLeftOnDevice                   , System               , UNPROCESSABLE_ENTITY;
-PayloadTooLarge                       , InvalidRequest       , PAYLOAD_TOO_LARGE ;
-TaskNotFound                          , InvalidRequest       , NOT_FOUND ;
-TooManyOpenFiles                      , System               , UNPROCESSABLE_ENTITY ;
-UnretrievableDocument                 , Internal             , BAD_REQUEST ;
-UnretrievableErrorCode                , InvalidRequest       , BAD_REQUEST ;
-UnsupportedMediaType                  , InvalidRequest       , UNSUPPORTED_MEDIA_TYPE
+ApiKeyAlreadyExists                         , InvalidRequest       , CONFLICT ;
+ApiKeyNotFound                              , InvalidRequest       , NOT_FOUND ;
+BadParameter                                , InvalidRequest       , BAD_REQUEST;
+BadRequest                                  , InvalidRequest       , BAD_REQUEST;
+DatabaseSizeLimitReached                    , Internal             , INTERNAL_SERVER_ERROR;
+DocumentNotFound                            , InvalidRequest       , NOT_FOUND;
+DumpAlreadyProcessing                       , InvalidRequest       , CONFLICT;
+DumpNotFound                                , InvalidRequest       , NOT_FOUND;
+DumpProcessFailed                           , Internal             , INTERNAL_SERVER_ERROR;
+DuplicateIndexFound                         , InvalidRequest       , BAD_REQUEST;
+ImmutableApiKeyActions                      , InvalidRequest       , BAD_REQUEST;
+ImmutableApiKeyCreatedAt                    , InvalidRequest       , BAD_REQUEST;
+ImmutableApiKeyExpiresAt                    , InvalidRequest       , BAD_REQUEST;
+ImmutableApiKeyIndexes                      , InvalidRequest       , BAD_REQUEST;
+ImmutableApiKeyKey                          , InvalidRequest       , BAD_REQUEST;
+ImmutableApiKeyUid                          , InvalidRequest       , BAD_REQUEST;
+ImmutableApiKeyUpdatedAt                    , InvalidRequest       , BAD_REQUEST;
+ImmutableIndexCreatedAt                     , InvalidRequest       , BAD_REQUEST;
+ImmutableIndexUid                           , InvalidRequest       , BAD_REQUEST;
+ImmutableIndexUpdatedAt                     , InvalidRequest       , BAD_REQUEST;
+IndexAlreadyExists                          , InvalidRequest       , CONFLICT ;
+IndexCreationFailed                         , Internal             , INTERNAL_SERVER_ERROR;
+IndexNotFound                               , InvalidRequest       , NOT_FOUND;
+IndexPrimaryKeyAlreadyExists                , InvalidRequest       , BAD_REQUEST ;
+IndexPrimaryKeyMultipleCandidatesFound      , InvalidRequest       , BAD_REQUEST;
+IndexPrimaryKeyNoCandidateFound             , InvalidRequest       , BAD_REQUEST ;
+Internal                                    , Internal             , INTERNAL_SERVER_ERROR ;
+InvalidApiKey                               , Auth                 , FORBIDDEN ;
+InvalidApiKeyActions                        , InvalidRequest       , BAD_REQUEST ;
+InvalidApiKeyDescription                    , InvalidRequest       , BAD_REQUEST ;
+InvalidApiKeyExpiresAt                      , InvalidRequest       , BAD_REQUEST ;
+InvalidApiKeyIndexes                        , InvalidRequest       , BAD_REQUEST ;
+InvalidApiKeyLimit                          , InvalidRequest       , BAD_REQUEST ;
+InvalidApiKeyName                           , InvalidRequest       , BAD_REQUEST ;
+InvalidApiKeyOffset                         , InvalidRequest       , BAD_REQUEST ;
+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 ;
+InvalidIndexLimit                           , InvalidRequest       , BAD_REQUEST ;
+InvalidIndexOffset                          , InvalidRequest       , BAD_REQUEST ;
+InvalidIndexPrimaryKey                      , InvalidRequest       , BAD_REQUEST ;
+InvalidIndexUid                             , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchAttributesToCrop               , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchAttributesToHighlight          , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchAttributesToRetrieve           , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchCropLength                     , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchCropMarker                     , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchFacets                         , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchFilter                         , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchHighlightPostTag               , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchHighlightPreTag                , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchHitsPerPage                    , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchLimit                          , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchMatchingStrategy               , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchOffset                         , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchPage                           , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchQ                              , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchShowMatchesPosition            , InvalidRequest       , BAD_REQUEST ;
+InvalidSearchSort                           , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsDisplayedAttributes          , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsDistinctAttribute            , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsFilterableAttributes         , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsPagination                   , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsRankingRules                 , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsSearchableAttributes         , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsSortableAttributes           , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsStopWords                    , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsSynonyms                     , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsTypoTolerance                , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsFaceting                     , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsFacetingMaxValuesPerFacet    , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsFacetingSortFacetValuesBy    , InvalidRequest       , BAD_REQUEST ;
+InvalidState                                , Internal             , INTERNAL_SERVER_ERROR ;
+InvalidStoreFile                            , Internal             , INTERNAL_SERVER_ERROR ;
+InvalidSwapDuplicateIndexFound              , InvalidRequest       , BAD_REQUEST ;
+InvalidSwapIndexes                          , InvalidRequest       , BAD_REQUEST ;
+InvalidTaskAfterEnqueuedAt                  , InvalidRequest       , BAD_REQUEST ;
+InvalidTaskAfterFinishedAt                  , InvalidRequest       , BAD_REQUEST ;
+InvalidTaskAfterStartedAt                   , InvalidRequest       , BAD_REQUEST ;
+InvalidTaskBeforeEnqueuedAt                 , InvalidRequest       , BAD_REQUEST ;
+InvalidTaskBeforeFinishedAt                 , InvalidRequest       , BAD_REQUEST ;
+InvalidTaskBeforeStartedAt                  , InvalidRequest       , BAD_REQUEST ;
+InvalidTaskCanceledBy                       , InvalidRequest       , BAD_REQUEST ;
+InvalidTaskFrom                             , InvalidRequest       , BAD_REQUEST ;
+InvalidTaskLimit                            , InvalidRequest       , BAD_REQUEST ;
+InvalidTaskStatuses                         , InvalidRequest       , BAD_REQUEST ;
+InvalidTaskTypes                            , InvalidRequest       , BAD_REQUEST ;
+InvalidTaskUids                             , InvalidRequest       , BAD_REQUEST  ;
+IoError                                     , System               , UNPROCESSABLE_ENTITY;
+MalformedPayload                            , InvalidRequest       , BAD_REQUEST ;
+MaxFieldsLimitExceeded                      , InvalidRequest       , BAD_REQUEST ;
+MissingApiKeyActions                        , InvalidRequest       , BAD_REQUEST ;
+MissingApiKeyExpiresAt                      , InvalidRequest       , BAD_REQUEST ;
+MissingApiKeyIndexes                        , InvalidRequest       , BAD_REQUEST ;
+MissingAuthorizationHeader                  , Auth                 , UNAUTHORIZED ;
+MissingContentType                          , InvalidRequest       , UNSUPPORTED_MEDIA_TYPE ;
+MissingDocumentId                           , InvalidRequest       , BAD_REQUEST ;
+MissingIndexUid                             , InvalidRequest       , BAD_REQUEST ;
+MissingMasterKey                            , Auth                 , UNAUTHORIZED ;
+MissingPayload                              , InvalidRequest       , BAD_REQUEST ;
+MissingSwapIndexes                          , InvalidRequest       , BAD_REQUEST ;
+MissingTaskFilters                          , InvalidRequest       , BAD_REQUEST ;
+NoSpaceLeftOnDevice                         , System               , UNPROCESSABLE_ENTITY;
+PayloadTooLarge                             , InvalidRequest       , PAYLOAD_TOO_LARGE ;
+TaskNotFound                                , InvalidRequest       , NOT_FOUND ;
+TooManyOpenFiles                            , System               , UNPROCESSABLE_ENTITY ;
+UnretrievableDocument                       , Internal             , BAD_REQUEST ;
+UnretrievableErrorCode                      , InvalidRequest       , BAD_REQUEST ;
+UnsupportedMediaType                        , InvalidRequest       , UNSUPPORTED_MEDIA_TYPE
 }
 
 impl ErrorCode for JoinError {

meilisearch-types/src/facet_values_sort.rs

@@ -0,0 +1,33 @@
+use deserr::Deserr;
+use milli::OrderBy;
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Default, Copy, Clone, PartialEq, Eq, Serialize, Deserialize, Deserr)]
+#[serde(rename_all = "camelCase")]
+#[deserr(rename_all = camelCase)]
+pub enum FacetValuesSort {
+    /// Facet values are sorted in alphabetical order, ascending from A to Z.
+    #[default]
+    Alpha,
+    /// Facet values are sorted by decreasing count.
+    /// The count is the number of records containing this facet value in the results of the query.
+    Count,
+}
+
+impl From<FacetValuesSort> for OrderBy {
+    fn from(val: FacetValuesSort) -> Self {
+        match val {
+            FacetValuesSort::Alpha => OrderBy::Lexicographic,
+            FacetValuesSort::Count => OrderBy::Count,
+        }
+    }
+}
+
+impl From<OrderBy> for FacetValuesSort {
+    fn from(val: OrderBy) -> Self {
+        match val {
+            OrderBy::Lexicographic => FacetValuesSort::Alpha,
+            OrderBy::Count => FacetValuesSort::Count,
+        }
+    }
+}

meilisearch-types/src/lib.rs

@@ -2,6 +2,7 @@ pub mod compression;
 pub mod deserr;
 pub mod document_formats;
 pub mod error;
+pub mod facet_values_sort;
 pub mod index_uid;
 pub mod index_uid_pattern;
 pub mod keys;

meilisearch-types/src/settings.rs

@@ -14,6 +14,7 @@ use serde::{Deserialize, Serialize, Serializer};
 
 use crate::deserr::DeserrJsonError;
 use crate::error::deserr_codes::*;
+use crate::facet_values_sort::FacetValuesSort;
 
 /// The maximimum number of results that the engine
 /// will be able to return in one search call.
@@ -97,11 +98,14 @@ pub struct TypoSettings {
 
 #[derive(Debug, Clone, Default, Serialize, Deserialize, PartialEq, Eq, Deserr)]
 #[serde(deny_unknown_fields, rename_all = "camelCase")]
-#[deserr(rename_all = camelCase, deny_unknown_fields)]
+#[deserr(deny_unknown_fields, rename_all = camelCase, where_predicate = __Deserr_E: deserr::MergeWithError<DeserrJsonError<InvalidSettingsFaceting>> + deserr::MergeWithError<DeserrJsonError<InvalidSettingsFacetingMaxValuesPerFacet>> + deserr::MergeWithError<DeserrJsonError<InvalidSettingsFacetingSortFacetValuesBy>>)]
 pub struct FacetingSettings {
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
-    #[deserr(default)]
+    #[deserr(default, error = DeserrJsonError<InvalidSettingsFacetingMaxValuesPerFacet>)]
     pub max_values_per_facet: Setting<usize>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default, error = DeserrJsonError<InvalidSettingsFacetingSortFacetValuesBy>)]
+    pub sort_facet_values_by: Setting<BTreeMap<String, FacetValuesSort>>,
 }
 
 #[derive(Debug, Clone, Default, Serialize, Deserialize, PartialEq, Eq, Deserr)]
@@ -398,12 +402,21 @@ pub fn apply_settings_to_builder(
         Setting::NotSet => (),
     }
 
-    match settings.faceting {
-        Setting::Set(ref value) => match value.max_values_per_facet {
-            Setting::Set(val) => builder.set_max_values_per_facet(val),
-            Setting::Reset => builder.reset_max_values_per_facet(),
-            Setting::NotSet => (),
-        },
+    match &settings.faceting {
+        Setting::Set(FacetingSettings { max_values_per_facet, sort_facet_values_by }) => {
+            match max_values_per_facet {
+                Setting::Set(val) => builder.set_max_values_per_facet(*val),
+                Setting::Reset => builder.reset_max_values_per_facet(),
+                Setting::NotSet => (),
+            }
+            match sort_facet_values_by {
+                Setting::Set(val) => builder.set_sort_facet_values_by(
+                    val.iter().map(|(name, order)| (name.clone(), (*order).into())).collect(),
+                ),
+                Setting::Reset => builder.reset_sort_facet_values_by(),
+                Setting::NotSet => (),
+            }
+        }
         Setting::Reset => builder.reset_max_values_per_facet(),
         Setting::NotSet => (),
     }
@@ -476,6 +489,13 @@ pub fn settings(
         max_values_per_facet: Setting::Set(
             index.max_values_per_facet(rtxn)?.unwrap_or(DEFAULT_VALUES_PER_FACET),
         ),
+        sort_facet_values_by: Setting::Set(
+            index
+                .sort_facet_values_by(rtxn)?
+                .into_iter()
+                .map(|(name, sort)| (name, sort.into()))
+                .collect(),
+        ),
     };
 
     let pagination = PaginationSettings {

meilisearch/Cargo.toml

@@ -14,14 +14,27 @@ default-run = "meilisearch"
 
 [dependencies]
 actix-cors = "0.6.4"
-actix-http = { version = "3.3.1", default-features = false, features = ["compress-brotli", "compress-gzip", "rustls"] }
-actix-web = { version = "4.3.1", default-features = false, features = ["macros", "compress-brotli", "compress-gzip", "cookies", "rustls"] }
+actix-http = { version = "3.3.1", default-features = false, features = [
+    "compress-brotli",
+    "compress-gzip",
+    "rustls",
+] }
+actix-web = { version = "4.3.1", default-features = false, features = [
+    "macros",
+    "compress-brotli",
+    "compress-gzip",
+    "cookies",
+    "rustls",
+] }
 actix-web-static-files = { git = "https://github.com/kilork/actix-web-static-files.git", rev = "2d3b6160", optional = true }
 anyhow = { version = "1.0.70", features = ["backtrace"] }
 async-stream = "0.3.5"
 async-trait = "0.1.68"
 bstr = "1.4.0"
-byte-unit = { version = "4.0.19", default-features = false, features = ["std", "serde"] }
+byte-unit = { version = "4.0.19", default-features = false, features = [
+    "std",
+    "serde",
+] }
 bytes = "1.4.0"
 clap = { version = "4.2.1", features = ["derive", "env"] }
 crossbeam-channel = "0.5.8"
@@ -56,7 +69,10 @@ prometheus = { version = "0.13.3", features = ["process"] }
 rand = "0.8.5"
 rayon = "1.7.0"
 regex = "1.7.3"
-reqwest = { version = "0.11.16", features = ["rustls-tls", "json"], default-features = false }
+reqwest = { version = "0.11.16", features = [
+    "rustls-tls",
+    "json",
+], default-features = false }
 rustls = "0.20.8"
 rustls-pemfile = "1.0.2"
 segment = { version = "0.2.2", optional = true }
@@ -70,7 +86,12 @@ sysinfo = "0.28.4"
 tar = "0.4.38"
 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",
+] }
 tokio = { version = "1.27.0", features = ["full"] }
 tokio-stream = "0.1.12"
 toml = "0.7.3"
@@ -89,7 +110,7 @@ brotli = "3.3.4"
 insta = "1.29.0"
 manifest-dir-macros = "0.1.16"
 maplit = "1.0.2"
-meili-snap = {path = "../meili-snap"}
+meili-snap = { path = "../meili-snap" }
 temp-env = "0.3.3"
 urlencoding = "2.1.2"
 yaup = "0.2.1"
@@ -98,7 +119,10 @@ yaup = "0.2.1"
 anyhow = { version = "1.0.70", optional = true }
 cargo_toml = { version = "0.15.2", optional = true }
 hex = { version = "0.4.3", optional = true }
-reqwest = { version = "0.11.16", features = ["blocking", "rustls-tls"], default-features = false, optional = true }
+reqwest = { version = "0.11.16", features = [
+    "blocking",
+    "rustls-tls",
+], default-features = false, optional = true }
 sha-1 = { version = "0.10.1", optional = true }
 static-files = { version = "0.2.3", optional = true }
 tempfile = { version = "3.5.0", optional = true }
@@ -108,7 +132,17 @@ zip = { version = "0.6.4", optional = true }
 [features]
 default = ["analytics", "meilisearch-types/all-tokenizations", "mini-dashboard"]
 analytics = ["segment"]
-mini-dashboard = ["actix-web-static-files", "static-files", "anyhow", "cargo_toml", "hex", "reqwest", "sha-1", "tempfile", "zip"]
+mini-dashboard = [
+    "actix-web-static-files",
+    "static-files",
+    "anyhow",
+    "cargo_toml",
+    "hex",
+    "reqwest",
+    "sha-1",
+    "tempfile",
+    "zip",
+]
 chinese = ["meilisearch-types/chinese"]
 hebrew = ["meilisearch-types/hebrew"]
 japanese = ["meilisearch-types/japanese"]

meilisearch/src/routes/indexes/settings.rs

@@ -407,6 +407,7 @@ make_setting_route!(
             json!({
                 "faceting": {
                     "max_values_per_facet": setting.as_ref().and_then(|s| s.max_values_per_facet.set()),
+                    "sort_facet_values_by": setting.as_ref().and_then(|s| s.sort_facet_values_by.clone().set()),
                 },
             }),
             Some(req),
@@ -545,6 +546,10 @@ pub async fn update_all(
                     .as_ref()
                     .set()
                     .and_then(|s| s.max_values_per_facet.as_ref().set()),
+                "sort_facet_values_by": new_settings.faceting
+                    .as_ref()
+                    .set()
+                    .and_then(|s| s.sort_facet_values_by.as_ref().set()),
             },
             "pagination": {
                 "max_total_hits": new_settings.pagination

meilisearch/src/search.rs

@@ -5,6 +5,7 @@ use std::time::Instant;
 
 use deserr::Deserr;
 use either::Either;
+use indexmap::IndexMap;
 use meilisearch_auth::IndexSearchRules;
 use meilisearch_types::deserr::DeserrJsonError;
 use meilisearch_types::error::deserr_codes::*;
@@ -213,7 +214,7 @@ pub struct SearchResult {
     #[serde(flatten)]
     pub hits_info: HitsInfo,
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub facet_distribution: Option<BTreeMap<String, BTreeMap<String, u64>>>,
+    pub facet_distribution: Option<BTreeMap<String, IndexMap<String, u64>>>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub facet_stats: Option<BTreeMap<String, FacetStats>>,
 }
@@ -448,10 +449,30 @@ pub fn perform_search(
                 .unwrap_or(DEFAULT_VALUES_PER_FACET);
             facet_distribution.max_values_per_facet(max_values_by_facet);
 
+            let sort_facet_values_by =
+                index.sort_facet_values_by(&rtxn).map_err(milli::Error::from)?;
+            let default_sort_facet_values_by =
+                sort_facet_values_by.get("*").copied().unwrap_or_default();
+
             if fields.iter().all(|f| f != "*") {
+                let fields: Vec<_> = fields
+                    .into_iter()
+                    .map(|n| {
+                        (
+                            n,
+                            sort_facet_values_by
+                                .get(n)
+                                .copied()
+                                .unwrap_or(default_sort_facet_values_by),
+                        )
+                    })
+                    .collect();
                 facet_distribution.facets(fields);
             }
-            let distribution = facet_distribution.candidates(candidates).execute()?;
+            let distribution = facet_distribution
+                .candidates(candidates)
+                .default_order_by(default_sort_facet_values_by)
+                .execute()?;
             let stats = facet_distribution.compute_stats()?;
             (Some(distribution), Some(stats))
         }

milli/Cargo.toml

@@ -32,6 +32,7 @@ heed = { git = "https://github.com/meilisearch/heed", tag = "v0.12.6", default-f
     "lmdb",
     "sync-read-txn",
 ] }
+indexmap = { version = "1.9.3", features = ["serde"] }
 json-depth-checker = { path = "../json-depth-checker" }
 levenshtein_automata = { version = "0.2.1", features = ["fst_automaton"] }
 memmap2 = "0.5.10"

milli/src/index.rs

@@ -23,8 +23,8 @@ use crate::heed_codec::{ScriptLanguageCodec, StrBEU16Codec, StrRefCodec};
 use crate::{
     default_criteria, BEU32StrCodec, BoRoaringBitmapCodec, CboRoaringBitmapCodec, Criterion,
     DocumentId, ExternalDocumentsIds, FacetDistribution, FieldDistribution, FieldId,
-    FieldIdWordCountCodec, GeoPoint, ObkvCodec, Result, RoaringBitmapCodec, RoaringBitmapLenCodec,
-    Search, U8StrStrCodec, BEU16, BEU32,
+    FieldIdWordCountCodec, GeoPoint, ObkvCodec, OrderBy, Result, RoaringBitmapCodec,
+    RoaringBitmapLenCodec, Search, U8StrStrCodec, BEU16, BEU32,
 };
 
 pub const DEFAULT_MIN_WORD_LEN_ONE_TYPO: u8 = 5;
@@ -62,6 +62,7 @@ pub mod main_key {
     pub const EXACT_WORDS: &str = "exact-words";
     pub const EXACT_ATTRIBUTES: &str = "exact-attributes";
     pub const MAX_VALUES_PER_FACET: &str = "max-values-per-facet";
+    pub const SORT_FACET_VALUES_BY: &str = "sort-facet-values-by";
     pub const PAGINATION_MAX_TOTAL_HITS: &str = "pagination-max-total-hits";
 }
 
@@ -1234,6 +1235,31 @@ impl Index {
         self.main.delete::<_, Str>(txn, main_key::MAX_VALUES_PER_FACET)
     }
 
+    pub fn sort_facet_values_by(&self, txn: &RoTxn) -> heed::Result<HashMap<String, OrderBy>> {
+        let mut orders = self
+            .main
+            .get::<_, Str, SerdeJson<HashMap<String, OrderBy>>>(
+                txn,
+                main_key::SORT_FACET_VALUES_BY,
+            )?
+            .unwrap_or_default();
+        // Insert the default ordering if it is not already overwritten by the user.
+        orders.entry("*".to_string()).or_insert(OrderBy::Lexicographic);
+        Ok(orders)
+    }
+
+    pub(crate) fn put_sort_facet_values_by(
+        &self,
+        txn: &mut RwTxn,
+        val: &HashMap<String, OrderBy>,
+    ) -> heed::Result<()> {
+        self.main.put::<_, Str, SerdeJson<_>>(txn, main_key::SORT_FACET_VALUES_BY, &val)
+    }
+
+    pub(crate) fn delete_sort_facet_values_by(&self, txn: &mut RwTxn) -> heed::Result<bool> {
+        self.main.delete::<_, Str>(txn, main_key::SORT_FACET_VALUES_BY)
+    }
+
     pub fn pagination_max_total_hits(&self, txn: &RoTxn) -> heed::Result<Option<usize>> {
         self.main.get::<_, Str, OwnedType<usize>>(txn, main_key::PAGINATION_MAX_TOTAL_HITS)
     }
@@ -1472,9 +1498,9 @@ pub(crate) mod tests {
 
         db_snap!(index, field_distribution,
             @r###"
-        age              1     
-        id               2     
-        name             2     
+        age              1
+        id               2
+        name             2
         "###
         );
 
@@ -1492,9 +1518,9 @@ pub(crate) mod tests {
 
         db_snap!(index, field_distribution,
             @r###"
-        age              1     
-        id               2     
-        name             2     
+        age              1
+        id               2
+        name             2
         "###
         );
 
@@ -1508,9 +1534,9 @@ pub(crate) mod tests {
 
         db_snap!(index, field_distribution,
             @r###"
-        has_dog          1     
-        id               2     
-        name             2     
+        has_dog          1
+        id               2
+        name             2
         "###
         );
     }

milli/src/lib.rs

@@ -99,8 +99,8 @@ pub use self::heed_codec::{
 };
 pub use self::index::Index;
 pub use self::search::{
-    FacetDistribution, Filter, FormatOptions, MatchBounds, MatcherBuilder, MatchingWords, Search,
-    SearchResult, TermsMatchingStrategy, DEFAULT_VALUES_PER_FACET,
+    FacetDistribution, Filter, FormatOptions, MatchBounds, MatcherBuilder, MatchingWords, OrderBy,
+    Search, SearchResult, TermsMatchingStrategy, DEFAULT_VALUES_PER_FACET,
 };
 
 pub type Result<T> = std::result::Result<T, error::Error>;

milli/src/search/facet/facet_distribution.rs

@@ -1,19 +1,22 @@
-use std::collections::{BTreeMap, HashSet};
+use std::collections::{BTreeMap, HashMap, HashSet};
 use std::ops::ControlFlow;
 use std::{fmt, mem};
 
 use heed::types::ByteSlice;
 use heed::BytesDecode;
+use indexmap::IndexMap;
 use roaring::RoaringBitmap;
+use serde::{Deserialize, Serialize};
 
 use crate::error::UserError;
 use crate::facet::FacetType;
 use crate::heed_codec::facet::{
-    FacetGroupKeyCodec, FacetGroupValueCodec, FieldDocIdFacetF64Codec, FieldDocIdFacetStringCodec,
-    OrderedF64Codec,
+    FacetGroupKeyCodec, FieldDocIdFacetF64Codec, FieldDocIdFacetStringCodec, OrderedF64Codec,
 };
 use crate::heed_codec::{ByteSliceRefCodec, StrRefCodec};
-use crate::search::facet::facet_distribution_iter;
+use crate::search::facet::facet_distribution_iter::{
+    count_iterate_over_facet_distribution, lexicographically_iterate_over_facet_distribution,
+};
 use crate::{FieldId, Index, Result};
 
 /// The default number of values by facets that will
@@ -24,10 +27,21 @@ pub const DEFAULT_VALUES_PER_FACET: usize = 100;
 /// the system to choose between one algorithm or another.
 const CANDIDATES_THRESHOLD: u64 = 3000;
 
+/// How should we fetch the facets?
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+pub enum OrderBy {
+    /// By lexicographic order...
+    #[default]
+    Lexicographic,
+    /// Or by number of docids in common?
+    Count,
+}
+
 pub struct FacetDistribution<'a> {
-    facets: Option<HashSet<String>>,
+    facets: Option<HashMap<String, OrderBy>>,
     candidates: Option<RoaringBitmap>,
     max_values_per_facet: usize,
+    default_order_by: OrderBy,
     rtxn: &'a heed::RoTxn<'a>,
     index: &'a Index,
 }
@@ -38,13 +52,22 @@ impl<'a> FacetDistribution<'a> {
             facets: None,
             candidates: None,
             max_values_per_facet: DEFAULT_VALUES_PER_FACET,
+            default_order_by: OrderBy::default(),
             rtxn,
             index,
         }
     }
 
-    pub fn facets<I: IntoIterator<Item = A>, A: AsRef<str>>(&mut self, names: I) -> &mut Self {
-        self.facets = Some(names.into_iter().map(|s| s.as_ref().to_string()).collect());
+    pub fn facets<I: IntoIterator<Item = (A, OrderBy)>, A: AsRef<str>>(
+        &mut self,
+        names_ordered_by: I,
+    ) -> &mut Self {
+        self.facets = Some(
+            names_ordered_by
+                .into_iter()
+                .map(|(name, order_by)| (name.as_ref().to_string(), order_by))
+                .collect(),
+        );
         self
     }
 
@@ -53,6 +76,11 @@ impl<'a> FacetDistribution<'a> {
         self
     }
 
+    pub fn default_order_by(&mut self, order_by: OrderBy) -> &mut Self {
+        self.default_order_by = order_by;
+        self
+    }
+
     pub fn candidates(&mut self, candidates: RoaringBitmap) -> &mut Self {
         self.candidates = Some(candidates);
         self
@@ -65,7 +93,7 @@ impl<'a> FacetDistribution<'a> {
         field_id: FieldId,
         facet_type: FacetType,
         candidates: &RoaringBitmap,
-        distribution: &mut BTreeMap<String, u64>,
+        distribution: &mut IndexMap<String, u64>,
     ) -> heed::Result<()> {
         match facet_type {
             FacetType::Number => {
@@ -134,9 +162,15 @@ impl<'a> FacetDistribution<'a> {
         &self,
         field_id: FieldId,
         candidates: &RoaringBitmap,
-        distribution: &mut BTreeMap<String, u64>,
+        order_by: OrderBy,
+        distribution: &mut IndexMap<String, u64>,
     ) -> heed::Result<()> {
-        facet_distribution_iter::iterate_over_facet_distribution(
+        let search_function = match order_by {
+            OrderBy::Lexicographic => lexicographically_iterate_over_facet_distribution,
+            OrderBy::Count => count_iterate_over_facet_distribution,
+        };
+
+        search_function(
             self.rtxn,
             self.index
                 .facet_id_f64_docids
@@ -159,9 +193,15 @@ impl<'a> FacetDistribution<'a> {
         &self,
         field_id: FieldId,
         candidates: &RoaringBitmap,
-        distribution: &mut BTreeMap<String, u64>,
+        order_by: OrderBy,
+        distribution: &mut IndexMap<String, u64>,
     ) -> heed::Result<()> {
-        facet_distribution_iter::iterate_over_facet_distribution(
+        let search_function = match order_by {
+            OrderBy::Lexicographic => lexicographically_iterate_over_facet_distribution,
+            OrderBy::Count => count_iterate_over_facet_distribution,
+        };
+
+        search_function(
             self.rtxn,
             self.index
                 .facet_id_string_docids
@@ -189,93 +229,48 @@ impl<'a> FacetDistribution<'a> {
         )
     }
 
-    /// Placeholder search, a.k.a. no candidates were specified. We iterate throught the
-    /// facet values one by one and iterate on the facet level 0 for numbers.
-    fn facet_values_from_raw_facet_database(
+    fn facet_values(
         &self,
         field_id: FieldId,
-    ) -> heed::Result<BTreeMap<String, u64>> {
-        let mut distribution = BTreeMap::new();
-
-        let db = self.index.facet_id_f64_docids;
-        let mut prefix = vec![];
-        prefix.extend_from_slice(&field_id.to_be_bytes());
-        prefix.push(0); // read values from level 0 only
-
-        let iter = db
-            .as_polymorph()
-            .prefix_iter::<_, ByteSlice, ByteSlice>(self.rtxn, prefix.as_slice())?
-            .remap_types::<FacetGroupKeyCodec<OrderedF64Codec>, FacetGroupValueCodec>();
-
-        for result in iter {
-            let (key, value) = result?;
-            distribution.insert(key.left_bound.to_string(), value.bitmap.len());
-            if distribution.len() == self.max_values_per_facet {
-                break;
-            }
-        }
-
-        let iter = self
-            .index
-            .facet_id_string_docids
-            .as_polymorph()
-            .prefix_iter::<_, ByteSlice, ByteSlice>(self.rtxn, prefix.as_slice())?
-            .remap_types::<FacetGroupKeyCodec<StrRefCodec>, FacetGroupValueCodec>();
-
-        for result in iter {
-            let (key, value) = result?;
-
-            let docid = value.bitmap.iter().next().unwrap();
-            let key: (FieldId, _, &'a str) = (field_id, docid, key.left_bound);
-            let original_string =
-                self.index.field_id_docid_facet_strings.get(self.rtxn, &key)?.unwrap().to_owned();
-
-            distribution.insert(original_string, value.bitmap.len());
-            if distribution.len() == self.max_values_per_facet {
-                break;
-            }
-        }
-
-        Ok(distribution)
-    }
-
-    fn facet_values(&self, field_id: FieldId) -> heed::Result<BTreeMap<String, u64>> {
+        order_by: OrderBy,
+    ) -> heed::Result<IndexMap<String, u64>> {
         use FacetType::{Number, String};
 
-        match self.candidates {
-            Some(ref candidates) => {
+        let mut distribution = IndexMap::new();
+        match (order_by, &self.candidates) {
+            (OrderBy::Lexicographic, Some(cnd)) if cnd.len() <= CANDIDATES_THRESHOLD => {
                 // Classic search, candidates were specified, we must return facet values only related
                 // to those candidates. We also enter here for facet strings for performance reasons.
-                let mut distribution = BTreeMap::new();
-                if candidates.len() <= CANDIDATES_THRESHOLD {
-                    self.facet_distribution_from_documents(
-                        field_id,
-                        Number,
-                        candidates,
-                        &mut distribution,
-                    )?;
-                    self.facet_distribution_from_documents(
-                        field_id,
-                        String,
-                        candidates,
-                        &mut distribution,
-                    )?;
-                } else {
-                    self.facet_numbers_distribution_from_facet_levels(
-                        field_id,
-                        candidates,
-                        &mut distribution,
-                    )?;
-                    self.facet_strings_distribution_from_facet_levels(
-                        field_id,
-                        candidates,
-                        &mut distribution,
-                    )?;
-                }
-                Ok(distribution)
+                self.facet_distribution_from_documents(field_id, Number, cnd, &mut distribution)?;
+                self.facet_distribution_from_documents(field_id, String, cnd, &mut distribution)?;
             }
-            None => self.facet_values_from_raw_facet_database(field_id),
-        }
+            _ => {
+                let universe;
+                let candidates;
+                match &self.candidates {
+                    Some(cnd) => candidates = cnd,
+                    None => {
+                        universe = self.index.documents_ids(self.rtxn)?;
+                        candidates = &universe;
+                    }
+                }
+
+                self.facet_numbers_distribution_from_facet_levels(
+                    field_id,
+                    candidates,
+                    order_by,
+                    &mut distribution,
+                )?;
+                self.facet_strings_distribution_from_facet_levels(
+                    field_id,
+                    candidates,
+                    order_by,
+                    &mut distribution,
+                )?;
+            }
+        };
+
+        Ok(distribution)
     }
 
     pub fn compute_stats(&self) -> Result<BTreeMap<String, (f64, f64)>> {
@@ -291,6 +286,7 @@ impl<'a> FacetDistribution<'a> {
             Some(facets) => {
                 let invalid_fields: HashSet<_> = facets
                     .iter()
+                    .map(|(name, _)| name)
                     .filter(|facet| !crate::is_faceted(facet, &filterable_fields))
                     .collect();
                 if !invalid_fields.is_empty() {
@@ -300,7 +296,7 @@ impl<'a> FacetDistribution<'a> {
                     }
                     .into());
                 } else {
-                    facets.clone()
+                    facets.into_iter().map(|(name, _)| name).cloned().collect()
                 }
             }
             None => filterable_fields,
@@ -337,7 +333,7 @@ impl<'a> FacetDistribution<'a> {
         Ok(distribution)
     }
 
-    pub fn execute(&self) -> Result<BTreeMap<String, BTreeMap<String, u64>>> {
+    pub fn execute(&self) -> Result<BTreeMap<String, IndexMap<String, u64>>> {
         let fields_ids_map = self.index.fields_ids_map(self.rtxn)?;
         let filterable_fields = self.index.filterable_fields(self.rtxn)?;
 
@@ -345,6 +341,7 @@ impl<'a> FacetDistribution<'a> {
             Some(ref facets) => {
                 let invalid_fields: HashSet<_> = facets
                     .iter()
+                    .map(|(name, _)| name)
                     .filter(|facet| !crate::is_faceted(facet, &filterable_fields))
                     .collect();
                 if !invalid_fields.is_empty() {
@@ -354,7 +351,7 @@ impl<'a> FacetDistribution<'a> {
                     }
                     .into());
                 } else {
-                    facets.clone()
+                    facets.into_iter().map(|(name, _)| name).cloned().collect()
                 }
             }
             None => filterable_fields,
@@ -363,7 +360,13 @@ impl<'a> FacetDistribution<'a> {
         let mut distribution = BTreeMap::new();
         for (fid, name) in fields_ids_map.iter() {
             if crate::is_faceted(name, &fields) {
-                let values = self.facet_values(fid)?;
+                let order_by = self
+                    .facets
+                    .as_ref()
+                    .map(|facets| facets.get(name).copied())
+                    .flatten()
+                    .unwrap_or(self.default_order_by);
+                let values = self.facet_values(fid, order_by)?;
                 distribution.insert(name.to_string(), values);
             }
         }
@@ -374,13 +377,20 @@ impl<'a> FacetDistribution<'a> {
 
 impl fmt::Debug for FacetDistribution<'_> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let FacetDistribution { facets, candidates, max_values_per_facet, rtxn: _, index: _ } =
-            self;
+        let FacetDistribution {
+            facets,
+            candidates,
+            max_values_per_facet,
+            default_order_by,
+            rtxn: _,
+            index: _,
+        } = self;
 
         f.debug_struct("FacetDistribution")
             .field("facets", facets)
             .field("candidates", candidates)
             .field("max_values_per_facet", max_values_per_facet)
+            .field("default_order_by", default_order_by)
             .finish()
     }
 }
@@ -392,7 +402,7 @@ mod tests {
 
     use crate::documents::documents_batch_reader_from_objects;
     use crate::index::tests::TempIndex;
-    use crate::{milli_snap, FacetDistribution};
+    use crate::{milli_snap, FacetDistribution, OrderBy};
 
     #[test]
     fn few_candidates_few_facet_values() {
@@ -417,14 +427,14 @@ mod tests {
         let txn = index.read_txn().unwrap();
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .execute()
             .unwrap();
 
         milli_snap!(format!("{map:?}"), @r###"{"colour": {"Blue": 2, "RED": 1}}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates([0, 1, 2].iter().copied().collect())
             .execute()
             .unwrap();
@@ -432,7 +442,7 @@ mod tests {
         milli_snap!(format!("{map:?}"), @r###"{"colour": {"Blue": 2, "RED": 1}}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates([1, 2].iter().copied().collect())
             .execute()
             .unwrap();
@@ -443,7 +453,7 @@ mod tests {
         milli_snap!(format!("{map:?}"), @r###"{"colour": {"  blue": 1, "RED": 1}}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates([2].iter().copied().collect())
             .execute()
             .unwrap();
@@ -451,7 +461,7 @@ mod tests {
         milli_snap!(format!("{map:?}"), @r###"{"colour": {"RED": 1}}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates([0, 1, 2].iter().copied().collect())
             .max_values_per_facet(1)
             .execute()
@@ -489,14 +499,14 @@ mod tests {
         let txn = index.read_txn().unwrap();
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .execute()
             .unwrap();
 
         milli_snap!(format!("{map:?}"), @r###"{"colour": {"Blue": 4000, "Red": 6000}}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .max_values_per_facet(1)
             .execute()
             .unwrap();
@@ -504,7 +514,7 @@ mod tests {
         milli_snap!(format!("{map:?}"), @r###"{"colour": {"Blue": 4000}}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((0..10_000).collect())
             .execute()
             .unwrap();
@@ -512,7 +522,7 @@ mod tests {
         milli_snap!(format!("{map:?}"), @r###"{"colour": {"Blue": 4000, "Red": 6000}}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((0..5_000).collect())
             .execute()
             .unwrap();
@@ -520,7 +530,7 @@ mod tests {
         milli_snap!(format!("{map:?}"), @r###"{"colour": {"Blue": 2000, "Red": 3000}}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((0..5_000).collect())
             .execute()
             .unwrap();
@@ -528,7 +538,7 @@ mod tests {
         milli_snap!(format!("{map:?}"), @r###"{"colour": {"Blue": 2000, "Red": 3000}}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((0..5_000).collect())
             .max_values_per_facet(1)
             .execute()
@@ -566,14 +576,14 @@ mod tests {
         let txn = index.read_txn().unwrap();
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .execute()
             .unwrap();
 
         milli_snap!(format!("{map:?}"), "no_candidates", @"ac9229ed5964d893af96a7076e2f8af5");
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .max_values_per_facet(2)
             .execute()
             .unwrap();
@@ -581,7 +591,7 @@ mod tests {
         milli_snap!(format!("{map:?}"), "no_candidates_with_max_2", @r###"{"colour": {"0": 10, "1": 10}}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((0..10_000).collect())
             .execute()
             .unwrap();
@@ -589,7 +599,7 @@ mod tests {
         milli_snap!(format!("{map:?}"), "candidates_0_10_000", @"ac9229ed5964d893af96a7076e2f8af5");
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((0..5_000).collect())
             .execute()
             .unwrap();
@@ -626,14 +636,14 @@ mod tests {
         let txn = index.read_txn().unwrap();
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .compute_stats()
             .unwrap();
 
         milli_snap!(format!("{map:?}"), "no_candidates", @"{}");
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((0..1000).collect())
             .compute_stats()
             .unwrap();
@@ -641,7 +651,7 @@ mod tests {
         milli_snap!(format!("{map:?}"), "candidates_0_1000", @r###"{"colour": (0.0, 999.0)}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((217..777).collect())
             .compute_stats()
             .unwrap();
@@ -678,14 +688,14 @@ mod tests {
         let txn = index.read_txn().unwrap();
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .compute_stats()
             .unwrap();
 
         milli_snap!(format!("{map:?}"), "no_candidates", @"{}");
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((0..1000).collect())
             .compute_stats()
             .unwrap();
@@ -693,7 +703,7 @@ mod tests {
         milli_snap!(format!("{map:?}"), "candidates_0_1000", @r###"{"colour": (0.0, 1999.0)}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((217..777).collect())
             .compute_stats()
             .unwrap();
@@ -730,14 +740,14 @@ mod tests {
         let txn = index.read_txn().unwrap();
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .compute_stats()
             .unwrap();
 
         milli_snap!(format!("{map:?}"), "no_candidates", @"{}");
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((0..1000).collect())
             .compute_stats()
             .unwrap();
@@ -745,7 +755,7 @@ mod tests {
         milli_snap!(format!("{map:?}"), "candidates_0_1000", @r###"{"colour": (0.0, 999.0)}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((217..777).collect())
             .compute_stats()
             .unwrap();
@@ -786,14 +796,14 @@ mod tests {
         let txn = index.read_txn().unwrap();
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .compute_stats()
             .unwrap();
 
         milli_snap!(format!("{map:?}"), "no_candidates", @"{}");
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((0..1000).collect())
             .compute_stats()
             .unwrap();
@@ -801,7 +811,7 @@ mod tests {
         milli_snap!(format!("{map:?}"), "candidates_0_1000", @r###"{"colour": (0.0, 1998.0)}"###);
 
         let map = FacetDistribution::new(&txn, &index)
-            .facets(std::iter::once("colour"))
+            .facets(std::iter::once(("colour", OrderBy::default())))
             .candidates((217..777).collect())
             .compute_stats()
             .unwrap();

milli/src/search/facet/facet_distribution_iter.rs

@@ -1,3 +1,5 @@
+use std::cmp::Reverse;
+use std::collections::BinaryHeap;
 use std::ops::ControlFlow;
 
 use heed::Result;
@@ -19,7 +21,7 @@ use crate::DocumentId;
 ///
 /// The return value of the closure is a `ControlFlow<()>` which indicates whether we should
 /// keep iterating over the different facet values or stop.
-pub fn iterate_over_facet_distribution<'t, CB>(
+pub fn lexicographically_iterate_over_facet_distribution<'t, CB>(
     rtxn: &'t heed::RoTxn<'t>,
     db: heed::Database<FacetGroupKeyCodec<ByteSliceRefCodec>, FacetGroupValueCodec>,
     field_id: u16,
@@ -29,7 +31,7 @@ pub fn iterate_over_facet_distribution<'t, CB>(
 where
     CB: FnMut(&'t [u8], u64, DocumentId) -> Result<ControlFlow<()>>,
 {
-    let mut fd = FacetDistribution { rtxn, db, field_id, callback };
+    let mut fd = LexicographicFacetDistribution { rtxn, db, field_id, callback };
     let highest_level = get_highest_level(
         rtxn,
         db.remap_key_type::<FacetGroupKeyCodec<ByteSliceRefCodec>>(),
@@ -44,7 +46,99 @@ where
     }
 }
 
-struct FacetDistribution<'t, CB>
+pub fn count_iterate_over_facet_distribution<'t, CB>(
+    rtxn: &'t heed::RoTxn<'t>,
+    db: heed::Database<FacetGroupKeyCodec<ByteSliceRefCodec>, FacetGroupValueCodec>,
+    field_id: u16,
+    candidates: &RoaringBitmap,
+    mut callback: CB,
+) -> Result<()>
+where
+    CB: FnMut(&'t [u8], u64, DocumentId) -> Result<ControlFlow<()>>,
+{
+    #[derive(Debug, PartialOrd, Ord, PartialEq, Eq)]
+    struct LevelEntry<'t> {
+        /// The number of candidates in this entry.
+        count: u64,
+        /// The key level of the entry.
+        level: Reverse<u8>,
+        /// The left bound key.
+        left_bound: &'t [u8],
+        /// The number of keys we must look for after `left_bound`.
+        group_size: u8,
+        /// Any docid in the set of matching documents. Used to find the original facet string.
+        any_docid: u32,
+    }
+
+    // Represents the list of keys that we must explore.
+    let mut heap = BinaryHeap::new();
+    let highest_level = get_highest_level(
+        rtxn,
+        db.remap_key_type::<FacetGroupKeyCodec<ByteSliceRefCodec>>(),
+        field_id,
+    )?;
+
+    if let Some(first_bound) = get_first_facet_value::<ByteSliceRefCodec>(rtxn, db, field_id)? {
+        // We first fill the heap with values from the highest level
+        let starting_key =
+            FacetGroupKey { field_id, level: highest_level, left_bound: first_bound };
+        for el in db.range(rtxn, &(&starting_key..)).unwrap().take(usize::MAX) {
+            let (key, value) = el.unwrap();
+            // The range is unbounded on the right and the group size for the highest level is MAX,
+            // so we need to check that we are not iterating over the next field id
+            if key.field_id != field_id {
+                break;
+            }
+            let intersection = value.bitmap & candidates;
+            let count = intersection.len();
+            if count != 0 {
+                heap.push(LevelEntry {
+                    count,
+                    level: Reverse(key.level),
+                    left_bound: key.left_bound,
+                    group_size: value.size,
+                    any_docid: intersection.min().unwrap(),
+                });
+            }
+        }
+
+        while let Some(LevelEntry { count, level, left_bound, group_size, any_docid }) = heap.pop()
+        {
+            if let Reverse(0) = level {
+                match (callback)(left_bound, count, any_docid)? {
+                    ControlFlow::Continue(_) => (),
+                    ControlFlow::Break(_) => return Ok(()),
+                }
+            } else {
+                let starting_key = FacetGroupKey { field_id, level: level.0 - 1, left_bound };
+                for el in db.range(rtxn, &(&starting_key..)).unwrap().take(group_size as usize) {
+                    let (key, value) = el.unwrap();
+                    // The range is unbounded on the right and the group size for the highest level is MAX,
+                    // so we need to check that we are not iterating over the next field id
+                    if key.field_id != field_id {
+                        break;
+                    }
+                    let intersection = value.bitmap & candidates;
+                    let count = intersection.len();
+                    if count != 0 {
+                        heap.push(LevelEntry {
+                            count,
+                            level: Reverse(key.level),
+                            left_bound: key.left_bound,
+                            group_size: value.size,
+                            any_docid: intersection.min().unwrap(),
+                        });
+                    }
+                }
+            }
+        }
+    }
+
+    Ok(())
+}
+
+/// Iterate over the facets values by lexicographic order.
+struct LexicographicFacetDistribution<'t, CB>
 where
     CB: FnMut(&'t [u8], u64, DocumentId) -> Result<ControlFlow<()>>,
 {
@@ -54,7 +148,7 @@ where
     callback: CB,
 }
 
-impl<'t, CB> FacetDistribution<'t, CB>
+impl<'t, CB> LexicographicFacetDistribution<'t, CB>
 where
     CB: FnMut(&'t [u8], u64, DocumentId) -> Result<ControlFlow<()>>,
 {
@@ -86,6 +180,7 @@ where
         }
         Ok(ControlFlow::Continue(()))
     }
+
     fn iterate(
         &mut self,
         candidates: &RoaringBitmap,
@@ -116,7 +211,7 @@ where
                     value.size as usize,
                 )?;
                 match cf {
-                    ControlFlow::Continue(_) => {}
+                    ControlFlow::Continue(_) => (),
                     ControlFlow::Break(_) => return Ok(ControlFlow::Break(())),
                 }
             }
@@ -132,7 +227,7 @@ mod tests {
     use heed::BytesDecode;
     use roaring::RoaringBitmap;
 
-    use super::iterate_over_facet_distribution;
+    use super::lexicographically_iterate_over_facet_distribution;
     use crate::heed_codec::facet::OrderedF64Codec;
     use crate::milli_snap;
     use crate::search::facet::tests::{get_random_looking_index, get_simple_index};
@@ -144,7 +239,7 @@ mod tests {
             let txn = index.env.read_txn().unwrap();
             let candidates = (0..=255).collect::<RoaringBitmap>();
             let mut results = String::new();
-            iterate_over_facet_distribution(
+            lexicographically_iterate_over_facet_distribution(
                 &txn,
                 index.content,
                 0,
@@ -161,6 +256,7 @@ mod tests {
             txn.commit().unwrap();
         }
     }
+
     #[test]
     fn filter_distribution_all_stop_early() {
         let indexes = [get_simple_index(), get_random_looking_index()];
@@ -169,7 +265,7 @@ mod tests {
             let candidates = (0..=255).collect::<RoaringBitmap>();
             let mut results = String::new();
             let mut nbr_facets = 0;
-            iterate_over_facet_distribution(
+            lexicographically_iterate_over_facet_distribution(
                 &txn,
                 index.content,
                 0,

milli/src/search/facet/mod.rs

@@ -4,7 +4,7 @@ use heed::types::{ByteSlice, DecodeIgnore};
 use heed::{BytesDecode, RoTxn};
 use roaring::RoaringBitmap;
 
-pub use self::facet_distribution::{FacetDistribution, DEFAULT_VALUES_PER_FACET};
+pub use self::facet_distribution::{FacetDistribution, OrderBy, DEFAULT_VALUES_PER_FACET};
 pub use self::filter::{BadGeoError, Filter};
 use crate::heed_codec::facet::{FacetGroupKeyCodec, FacetGroupValueCodec, OrderedF64Codec};
 use crate::heed_codec::ByteSliceRefCodec;

milli/src/search/mod.rs

@@ -4,7 +4,7 @@ use levenshtein_automata::{LevenshteinAutomatonBuilder as LevBuilder, DFA};
 use once_cell::sync::Lazy;
 use roaring::bitmap::RoaringBitmap;
 
-pub use self::facet::{FacetDistribution, Filter, DEFAULT_VALUES_PER_FACET};
+pub use self::facet::{FacetDistribution, Filter, OrderBy, DEFAULT_VALUES_PER_FACET};
 pub use self::new::matches::{FormatOptions, MatchBounds, Matcher, MatcherBuilder, MatchingWords};
 use self::new::PartialSearchResult;
 use crate::{

milli/src/update/settings.rs

@@ -14,7 +14,7 @@ use crate::error::UserError;
 use crate::index::{DEFAULT_MIN_WORD_LEN_ONE_TYPO, DEFAULT_MIN_WORD_LEN_TWO_TYPOS};
 use crate::update::index_documents::IndexDocumentsMethod;
 use crate::update::{IndexDocuments, UpdateIndexingStep};
-use crate::{FieldsIdsMap, Index, Result};
+use crate::{FieldsIdsMap, Index, OrderBy, Result};
 
 #[derive(Debug, Clone, PartialEq, Eq, Copy)]
 pub enum Setting<T> {
@@ -122,6 +122,7 @@ pub struct Settings<'a, 't, 'u, 'i> {
     /// Attributes on which typo tolerance is disabled.
     exact_attributes: Setting<HashSet<String>>,
     max_values_per_facet: Setting<usize>,
+    sort_facet_values_by: Setting<HashMap<String, OrderBy>>,
     pagination_max_total_hits: Setting<usize>,
 }
 
@@ -149,6 +150,7 @@ impl<'a, 't, 'u, 'i> Settings<'a, 't, 'u, 'i> {
             min_word_len_one_typo: Setting::NotSet,
             exact_attributes: Setting::NotSet,
             max_values_per_facet: Setting::NotSet,
+            sort_facet_values_by: Setting::NotSet,
             pagination_max_total_hits: Setting::NotSet,
             indexer_config,
         }
@@ -275,6 +277,14 @@ impl<'a, 't, 'u, 'i> Settings<'a, 't, 'u, 'i> {
         self.max_values_per_facet = Setting::Reset;
     }
 
+    pub fn set_sort_facet_values_by(&mut self, value: HashMap<String, OrderBy>) {
+        self.sort_facet_values_by = Setting::Set(value);
+    }
+
+    pub fn reset_sort_facet_values_by(&mut self) {
+        self.sort_facet_values_by = Setting::Reset;
+    }
+
     pub fn set_pagination_max_total_hits(&mut self, value: usize) {
         self.pagination_max_total_hits = Setting::Set(value);
     }
@@ -680,6 +690,20 @@ impl<'a, 't, 'u, 'i> Settings<'a, 't, 'u, 'i> {
         Ok(())
     }
 
+    fn update_sort_facet_values_by(&mut self) -> Result<()> {
+        match self.sort_facet_values_by.as_ref() {
+            Setting::Set(value) => {
+                self.index.put_sort_facet_values_by(self.wtxn, value)?;
+            }
+            Setting::Reset => {
+                self.index.delete_sort_facet_values_by(self.wtxn)?;
+            }
+            Setting::NotSet => (),
+        }
+
+        Ok(())
+    }
+
     fn update_pagination_max_total_hits(&mut self) -> Result<()> {
         match self.pagination_max_total_hits {
             Setting::Set(max) => {
@@ -714,6 +738,7 @@ impl<'a, 't, 'u, 'i> Settings<'a, 't, 'u, 'i> {
         self.update_min_typo_word_len()?;
         self.update_exact_words()?;
         self.update_max_values_per_facet()?;
+        self.update_sort_facet_values_by()?;
         self.update_pagination_max_total_hits()?;
 
         // If there is new faceted fields we indicate that we must reindex as we must
@@ -1515,6 +1540,7 @@ mod tests {
                     exact_words,
                     exact_attributes,
                     max_values_per_facet,
+                    sort_facet_values_by,
                     pagination_max_total_hits,
                 } = settings;
                 assert!(matches!(searchable_fields, Setting::NotSet));
@@ -1532,6 +1558,7 @@ mod tests {
                 assert!(matches!(exact_words, Setting::NotSet));
                 assert!(matches!(exact_attributes, Setting::NotSet));
                 assert!(matches!(max_values_per_facet, Setting::NotSet));
+                assert!(matches!(sort_facet_values_by, Setting::NotSet));
                 assert!(matches!(pagination_max_total_hits, Setting::NotSet));
             })
             .unwrap();

milli/tests/search/facet_distribution.rs

@@ -5,7 +5,7 @@ use heed::EnvOpenOptions;
 use maplit::hashset;
 use milli::documents::{DocumentsBatchBuilder, DocumentsBatchReader};
 use milli::update::{IndexDocuments, IndexDocumentsConfig, IndexerConfig, Settings};
-use milli::{FacetDistribution, Index, Object};
+use milli::{FacetDistribution, Index, Object, OrderBy};
 use serde_json::Deserializer;
 
 #[test]
@@ -63,12 +63,12 @@ fn test_facet_distribution_with_no_facet_values() {
 
     let txn = index.read_txn().unwrap();
     let mut distrib = FacetDistribution::new(&txn, &index);
-    distrib.facets(vec!["genres"]);
+    distrib.facets(vec![("genres", OrderBy::default())]);
     let result = distrib.execute().unwrap();
     assert_eq!(result["genres"].len(), 0);
 
     let mut distrib = FacetDistribution::new(&txn, &index);
-    distrib.facets(vec!["tags"]);
+    distrib.facets(vec![("tags", OrderBy::default())]);
     let result = distrib.execute().unwrap();
     assert_eq!(result["tags"].len(), 2);
 }