From b833be46b9b1076d3dc2b26d7a1e197e55e887d7 Mon Sep 17 00:00:00 2001
From: ManyTheFish <many@meilisearch.com>
Date: Wed, 5 Jun 2024 12:48:44 +0200
Subject: [PATCH] Avoid running proximity when only the exact attributes
 changes

---
 .../extract_word_pair_proximity_docids.rs     |  9 ++++----
 milli/src/update/settings.rs                  | 22 +++++++++++++++----
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/milli/src/update/index_documents/extract/extract_word_pair_proximity_docids.rs b/milli/src/update/index_documents/extract/extract_word_pair_proximity_docids.rs
index 617338f9f..5a9363942 100644
--- a/milli/src/update/index_documents/extract/extract_word_pair_proximity_docids.rs
+++ b/milli/src/update/index_documents/extract/extract_word_pair_proximity_docids.rs
@@ -26,11 +26,8 @@ pub fn extract_word_pair_proximity_docids<R: io::Read + io::Seek>(
     indexer: GrenadParameters,
     settings_diff: &InnerIndexSettingsDiff,
 ) -> Result<grenad::Reader<BufReader<File>>> {
-    let any_deletion = settings_diff.old.proximity_precision == ProximityPrecision::ByWord;
-    let any_addition = settings_diff.new.proximity_precision == ProximityPrecision::ByWord;
-
     // early return if the data shouldn't be deleted nor created.
-    if !any_deletion && !any_addition {
+    if settings_diff.settings_update_only && !settings_diff.reindex_proximities() {
         let writer = create_writer(
             indexer.chunk_compression_type,
             indexer.chunk_compression_level,
@@ -39,8 +36,10 @@ pub fn extract_word_pair_proximity_docids<R: io::Read + io::Seek>(
         return writer_into_reader(writer);
     }
 
-    let max_memory = indexer.max_memory_by_thread();
+    let any_deletion = settings_diff.old.proximity_precision == ProximityPrecision::ByWord;
+    let any_addition = settings_diff.new.proximity_precision == ProximityPrecision::ByWord;
 
+    let max_memory = indexer.max_memory_by_thread();
     let mut word_pair_proximity_docids_sorters: Vec<_> = (1..MAX_DISTANCE)
         .map(|_| {
             create_sorter(
diff --git a/milli/src/update/settings.rs b/milli/src/update/settings.rs
index 952b017c6..dc26ac746 100644
--- a/milli/src/update/settings.rs
+++ b/milli/src/update/settings.rs
@@ -1104,8 +1104,10 @@ pub struct InnerIndexSettingsDiff {
     // Cache the check to see if all the stop_words, allowed_separators, dictionary,
     // exact_attributes, proximity_precision are different.
     pub(crate) cache_reindex_searchable_without_user_defined: bool,
-    // Cache the check to see if all the user_defined_searchables are different.
+    // Cache the check to see if the user_defined_searchables are different.
     pub(crate) cache_user_defined_searchables: bool,
+    // Cache the check to see if the exact_attributes are different.
+    pub(crate) cache_exact_attributes: bool,
 }
 
 impl InnerIndexSettingsDiff {
@@ -1139,10 +1141,11 @@ impl InnerIndexSettingsDiff {
                 != new_settings.stop_words.as_ref().map(|set| set.as_fst().as_bytes())
                 || old_settings.allowed_separators != new_settings.allowed_separators
                 || old_settings.dictionary != new_settings.dictionary
-                || old_settings.exact_attributes != new_settings.exact_attributes
                 || old_settings.proximity_precision != new_settings.proximity_precision
         };
 
+        let cache_exact_attributes = old_settings.exact_attributes != new_settings.exact_attributes;
+
         let cache_user_defined_searchables = old_settings.user_defined_searchable_fields
             != new_settings.user_defined_searchable_fields;
 
@@ -1155,6 +1158,7 @@ impl InnerIndexSettingsDiff {
             only_additional_fields,
             cache_reindex_searchable_without_user_defined,
             cache_user_defined_searchables,
+            cache_exact_attributes,
         }
     }
 
@@ -1163,11 +1167,21 @@ impl InnerIndexSettingsDiff {
     }
 
     pub fn reindex_searchable(&self) -> bool {
-        self.cache_reindex_searchable_without_user_defined || self.cache_user_defined_searchables
+        self.cache_reindex_searchable_without_user_defined
+            || self.cache_exact_attributes
+            || self.cache_user_defined_searchables
+    }
+
+    pub fn reindex_proximities(&self) -> bool {
+        // if any searchable settings force the reindexing
+        (self.cache_reindex_searchable_without_user_defined || self.cache_user_defined_searchables)
+        // and if any settings needs the proximity database created
+            && (self.old.proximity_precision == ProximityPrecision::ByAttribute
+                || self.old.proximity_precision == ProximityPrecision::ByAttribute)
     }
 
     pub fn reindex_searchable_id(&self, id: FieldId) -> Option<DelAddOperation> {
-        if self.cache_reindex_searchable_without_user_defined {
+        if self.cache_reindex_searchable_without_user_defined || self.cache_exact_attributes {
             Some(DelAddOperation::DeletionAndAddition)
         } else if let Some(only_additional_fields) = &self.only_additional_fields {
             let additional_field = self.new.fields_ids_map.name(id).unwrap();