Small changes following review

milli/src/update/index_documents/extract/extract_vector_points.rs

@@ -422,8 +422,11 @@ fn extract_vector_document_diff(
                 VectorStateDelta::NowRemoved
             }
         }
-        // when the vectors are no longer user-provided,
-        // we generate the prompt unconditionally
+        // inline to the left is not supposed to be possible because the embedder is not new, so `_vectors` was removed from
+        // the previous version of the document.
+        // Manual -> Generated is also not possible without an Inline to the right (which is handled above)
+        // Generated -> Generated is handled above, so not possible
+        // As a result, this code is unreachable
         (_not_generated, VectorState::Generated) => {
             // Do we keep this document?
             let document_is_kept = obkv
@@ -443,7 +446,10 @@ fn extract_vector_document_diff(
                 VectorStateDelta::NowRemoved
             }
         }
-        (_old, VectorState::Manual) => {
+        // inline to the left is not possible because the embedder is not new, and so `_vectors` was removed from the previous
+        // version of the document.
+        // however the Rust type system cannot know that.
+        (_manual, VectorState::Manual) => {
             // Do we keep this document?
             let document_is_kept = obkv
                 .iter()

milli/src/update/index_documents/transform.rs

@@ -866,6 +866,7 @@ impl<'a, 'i> Transform<'a, 'i> {
 
         // The operations that we must perform on the different fields.
         let mut operations = HashMap::new();
+        let mut error_seen = false;
 
         let mut obkv_writer = KvWriter::<_, FieldId>::memory();
         'write_fid: for (id, val) in old_obkv.iter() {
@@ -886,7 +887,10 @@ impl<'a, 'i> Transform<'a, 'i> {
                         match existing_vectors {
                             Ok(existing_vectors) => existing_vectors,
                             Err(error) => {
-                                tracing::error!(%error, "Unexpected `_vectors` field that is not a map. Treating as an empty map");
+                                if !error_seen {
+                                    tracing::error!(%error, "Unexpected `_vectors` field that is not a map. Treating as an empty map");
+                                    error_seen = true;
+                                }
                                 Default::default()
                             }
                         }

milli/src/update/settings.rs

@@ -1182,7 +1182,6 @@ pub struct InnerIndexSettingsDiff {
     pub(crate) old: InnerIndexSettings,
     pub(crate) new: InnerIndexSettings,
     pub(crate) primary_key_id: Option<FieldId>,
-    // TODO: compare directly the embedders.
     pub(crate) embedding_config_updates: BTreeMap<String, EmbedderAction>,
     pub(crate) settings_update_only: bool,
     /// The set of only the additional searchable fields.

milli/src/vector/settings.rs

@@ -101,13 +101,6 @@ pub struct WriteBackToDocuments {
 }
 
 impl SettingsDiff {
-    pub fn should_reindex(&self) -> bool {
-        match self {
-            SettingsDiff::Remove { .. } | SettingsDiff::Reindex { .. } => true,
-            SettingsDiff::UpdateWithoutReindex { .. } => false,
-        }
-    }
-
     pub fn from_settings(old: EmbeddingSettings, new: Setting<EmbeddingSettings>) -> Self {
         match new {
             Setting::Set(new) => {