Make the flattened sorter optional

milli/src/update/index_documents/mod.rs

@@ -360,7 +360,10 @@ where
                 let min_chunk_size = 1024 * 512; // 512KiB
 
                 // compute the chunk size from the number of available threads and the inputed data size.
-                let total_size = flattened_documents.metadata().map(|m| m.len());
+                let total_size = match flattened_documents.as_ref() {
+                    Some(flattened_documents) => flattened_documents.metadata().map(|m| m.len()),
+                    None => Ok(default_chunk_size as u64),
+                };
                 let current_num_threads = pool.current_num_threads();
                 // if we have more than 2 thread, create a number of chunk equal to 3/4 threads count
                 let chunk_count = if current_num_threads > 2 {
@@ -374,11 +377,14 @@ where
             }
         };
 
-        let flattened_documents = grenad::Reader::new(flattened_documents)?;
         let original_documents = match original_documents {
             Some(original_documents) => Some(grenad::Reader::new(original_documents)?),
             None => None,
         };
+        let flattened_documents = match flattened_documents {
+            Some(flattened_documents) => Some(grenad::Reader::new(flattened_documents)?),
+            None => None,
+        };
 
         let max_positions_per_attributes = self.indexer_config.max_positions_per_attributes;
 
@@ -400,22 +406,20 @@ where
                 let _enter = child_span.enter();
                 puffin::profile_scope!("extract_and_send_grenad_chunks");
                 // split obkv file into several chunks
-                let original_chunk_iter =
-                    match original_documents {
-                        Some(original_documents) => {
-                            grenad_obkv_into_chunks(
-                                original_documents,
-                                pool_params,
-                                documents_chunk_size
-                            )
-                            .map(either::Either::Left)
-                        },
-                        None => Ok(either::Right(iter::empty())),
-                    };
+                let original_chunk_iter = match original_documents {
+                    Some(original_documents) => {
+                        grenad_obkv_into_chunks(original_documents,pool_params,documents_chunk_size).map(either::Left)
+                    },
+                    None => Ok(either::Right(iter::empty())),
+                };
 
                 // split obkv file into several chunks
-                let flattened_chunk_iter =
-                    grenad_obkv_into_chunks(flattened_documents, pool_params, documents_chunk_size);
+                let flattened_chunk_iter = match flattened_documents {
+                    Some(flattened_documents) => {
+                        grenad_obkv_into_chunks(flattened_documents, pool_params, documents_chunk_size).map(either::Left)
+                    },
+                    None => Ok(either::Right(iter::empty())),
+                };
 
                 let result = original_chunk_iter.and_then(|original_chunk| {
                     let flattened_chunk = flattened_chunk_iter?;

milli/src/update/index_documents/transform.rs

@@ -34,7 +34,7 @@ pub struct TransformOutput {
     pub field_distribution: FieldDistribution,
     pub documents_count: usize,
     pub original_documents: Option<File>,
-    pub flattened_documents: File,
+    pub flattened_documents: Option<File>,
 }
 
 /// Extract the external ids, deduplicate and compute the new internal documents ids
@@ -825,9 +825,9 @@ impl<'a, 'i> Transform<'a, 'i> {
             original_documents: Some(
                 original_documents.into_inner().map_err(|err| err.into_error())?,
             ),
-            flattened_documents: flattened_documents
-                .into_inner()
-                .map_err(|err| err.into_error())?,
+            flattened_documents: Some(
+                flattened_documents.into_inner().map_err(|err| err.into_error())?,
+            ),
         })
     }
 
@@ -840,6 +840,9 @@ impl<'a, 'i> Transform<'a, 'i> {
         original_obkv_buffer: &mut Vec<u8>,
         flattened_obkv_buffer: &mut Vec<u8>,
     ) -> Result<()> {
+        /// TODO do a XOR of the faceted fields
+        /// TODO if reindex_searchable returns true store all searchables else none
+        /// TODO no longer useful after Tamo's PR
         let mut old_fields_ids_map = settings_diff.old.fields_ids_map.clone();
         let mut new_fields_ids_map = settings_diff.new.fields_ids_map.clone();
         let mut obkv_writer = KvWriter::<_, FieldId>::memory();
@@ -907,14 +910,19 @@ impl<'a, 'i> Transform<'a, 'i> {
         };
 
         // We initialize the sorter with the user indexing settings.
-        let mut flattened_sorter = create_sorter(
-            grenad::SortAlgorithm::Stable,
-            keep_first,
-            self.indexer_settings.chunk_compression_type,
-            self.indexer_settings.chunk_compression_level,
-            self.indexer_settings.max_nb_chunks,
-            self.indexer_settings.max_memory.map(|mem| mem / 2),
-        );
+        let mut flattened_sorter =
+            if settings_diff.reindex_searchable() || settings_diff.reindex_facets() {
+                Some(create_sorter(
+                    grenad::SortAlgorithm::Stable,
+                    keep_first,
+                    self.indexer_settings.chunk_compression_type,
+                    self.indexer_settings.chunk_compression_level,
+                    self.indexer_settings.max_nb_chunks,
+                    self.indexer_settings.max_memory.map(|mem| mem / 2),
+                ))
+            } else {
+                None
+            };
 
         let mut original_obkv_buffer = Vec::new();
         let mut flattened_obkv_buffer = Vec::new();
@@ -938,7 +946,9 @@ impl<'a, 'i> Transform<'a, 'i> {
             if let Some(original_sorter) = original_sorter.as_mut() {
                 original_sorter.insert(&document_sorter_key_buffer, &original_obkv_buffer)?;
             }
-            flattened_sorter.insert(docid.to_be_bytes(), &flattened_obkv_buffer)?;
+            if let Some(flattened_sorter) = flattened_sorter.as_mut() {
+                flattened_sorter.insert(docid.to_be_bytes(), &flattened_obkv_buffer)?;
+            }
         }
 
         let grenad_params = GrenadParameters {
@@ -949,7 +959,10 @@ impl<'a, 'i> Transform<'a, 'i> {
         };
 
         // Once we have written all the documents, we merge everything into a Reader.
-        let flattened_documents = sorter_into_reader(flattened_sorter, grenad_params)?;
+        let flattened_documents = match flattened_sorter {
+            Some(flattened_sorter) => Some(sorter_into_reader(flattened_sorter, grenad_params)?),
+            None => None,
+        };
         let original_documents = match original_sorter {
             Some(original_sorter) => Some(sorter_into_reader(original_sorter, grenad_params)?),
             None => None,
@@ -961,7 +974,7 @@ impl<'a, 'i> Transform<'a, 'i> {
             settings_diff,
             documents_count,
             original_documents: original_documents.map(|od| od.into_inner().into_inner()),
-            flattened_documents: flattened_documents.into_inner().into_inner(),
+            flattened_documents: flattened_documents.map(|fd| fd.into_inner().into_inner()),
         })
     }
 }

milli/src/update/settings.rs

@@ -1099,6 +1099,7 @@ impl InnerIndexSettingsDiff {
     }
 
     pub fn reindex_searchable(&self) -> bool {
+        // TODO no longer useful after Tamo's PR
         self.old
             .fields_ids_map
             .iter()