Add a database containing the docids where each field exists

infos/src/main.rs

@@ -384,6 +384,7 @@ fn biggest_value_sizes(index: &Index, rtxn: &heed::RoTxn, limit: usize) -> anyho
         field_id_word_count_docids,
         facet_id_f64_docids,
         facet_id_string_docids,
+        facet_id_exists_docids,
         exact_word_docids,
         exact_word_prefix_docids,
         field_id_docid_facet_f64s: _,
@@ -402,6 +403,7 @@ fn biggest_value_sizes(index: &Index, rtxn: &heed::RoTxn, limit: usize) -> anyho
     let field_id_word_count_docids_name = "field_id_word_count_docids";
     let facet_id_f64_docids_name = "facet_id_f64_docids";
     let facet_id_string_docids_name = "facet_id_string_docids";
+    let facet_id_exists_docids_name = "facet_id_exists_docids";
     let documents_name = "documents";
 
     let mut heap = BinaryHeap::with_capacity(limit + 1);
@@ -544,6 +546,17 @@ fn biggest_value_sizes(index: &Index, rtxn: &heed::RoTxn, limit: usize) -> anyho
                     heap.pop();
                 }
             }
+
+            // List the docids where the facet exists
+            let db = facet_id_exists_docids.remap_data_type::<ByteSlice>();
+            for result in facet_values_iter(rtxn, db, facet_id)? {
+                let (_fid, value) = result?;
+                let key = format!("{}", facet_name);
+                heap.push(Reverse((value.len(), key, facet_id_exists_docids_name)));
+                if heap.len() > limit {
+                    heap.pop();
+                }
+            }
         }
 
         for result in index.all_documents(rtxn)? {
@@ -984,6 +997,7 @@ fn size_of_databases(index: &Index, rtxn: &heed::RoTxn, names: Vec<String>) -> a
         facet_id_string_docids,
         field_id_docid_facet_f64s,
         field_id_docid_facet_strings,
+        facet_id_exists_docids,
         exact_word_prefix_docids,
         exact_word_docids,
         ..
@@ -1007,6 +1021,7 @@ fn size_of_databases(index: &Index, rtxn: &heed::RoTxn, names: Vec<String>) -> a
             FIELD_ID_WORD_COUNT_DOCIDS => field_id_word_count_docids.as_polymorph(),
             FACET_ID_F64_DOCIDS => facet_id_f64_docids.as_polymorph(),
             FACET_ID_STRING_DOCIDS => facet_id_string_docids.as_polymorph(),
+            FACET_ID_EXISTS_DOCIDS => facet_id_exists_docids.as_polymorph(),
             FIELD_ID_DOCID_FACET_F64S => field_id_docid_facet_f64s.as_polymorph(),
             FIELD_ID_DOCID_FACET_STRINGS => field_id_docid_facet_strings.as_polymorph(),
             EXACT_WORD_DOCIDS => exact_word_docids.as_polymorph(),

milli/src/heed_codec/facet/mod.rs

@@ -25,3 +25,43 @@ pub fn try_split_at(slice: &[u8], mid: usize) -> Option<(&[u8], &[u8])> {
         None
     }
 }
+
+use crate::{try_split_array_at, DocumentId, FieldId};
+use std::borrow::Cow;
+use std::convert::TryInto;
+
+pub struct FieldIdCodec;
+
+impl<'a> heed::BytesDecode<'a> for FieldIdCodec {
+    type DItem = FieldId;
+
+    fn bytes_decode(bytes: &'a [u8]) -> Option<Self::DItem> {
+        let (field_id_bytes, _) = try_split_array_at(bytes)?;
+        let field_id = u16::from_be_bytes(field_id_bytes);
+        Some(field_id)
+    }
+}
+
+impl<'a> heed::BytesEncode<'a> for FieldIdCodec {
+    type EItem = FieldId;
+
+    fn bytes_encode(field_id: &Self::EItem) -> Option<Cow<[u8]>> {
+        Some(Cow::Owned(field_id.to_be_bytes().to_vec()))
+    }
+}
+
+pub struct FieldIdDocIdCodec;
+
+impl<'a> heed::BytesDecode<'a> for FieldIdDocIdCodec {
+    type DItem = (FieldId, DocumentId);
+
+    fn bytes_decode(bytes: &'a [u8]) -> Option<Self::DItem> {
+        let (field_id_bytes, bytes) = try_split_array_at(bytes)?;
+        let field_id = u16::from_be_bytes(field_id_bytes);
+
+        let document_id_bytes = bytes[..4].try_into().ok()?;
+        let document_id = u32::from_be_bytes(document_id_bytes);
+
+        Some((field_id, document_id))
+    }
+}

milli/src/index.rs

@@ -15,7 +15,7 @@ use crate::error::{InternalError, UserError};
 use crate::fields_ids_map::FieldsIdsMap;
 use crate::heed_codec::facet::{
     FacetLevelValueF64Codec, FacetStringLevelZeroCodec, FacetStringLevelZeroValueCodec,
-    FieldDocIdFacetF64Codec, FieldDocIdFacetStringCodec,
+    FieldDocIdFacetF64Codec, FieldDocIdFacetStringCodec, FieldIdCodec,
 };
 use crate::{
     default_criteria, BEU32StrCodec, BoRoaringBitmapCodec, CboRoaringBitmapCodec, Criterion,
@@ -75,6 +75,7 @@ pub mod db_name {
     pub const WORD_PREFIX_POSITION_DOCIDS: &str = "word-prefix-position-docids";
     pub const FIELD_ID_WORD_COUNT_DOCIDS: &str = "field-id-word-count-docids";
     pub const FACET_ID_F64_DOCIDS: &str = "facet-id-f64-docids";
+    pub const FACET_ID_EXISTS_DOCIDS: &str = "facet-id-exists-docids";
     pub const FACET_ID_STRING_DOCIDS: &str = "facet-id-string-docids";
     pub const FIELD_ID_DOCID_FACET_F64S: &str = "field-id-docid-facet-f64s";
     pub const FIELD_ID_DOCID_FACET_STRINGS: &str = "field-id-docid-facet-strings";
@@ -116,6 +117,9 @@ pub struct Index {
     /// Maps the position of a word prefix with all the docids where this prefix appears.
     pub word_prefix_position_docids: Database<StrBEU32Codec, CboRoaringBitmapCodec>,
 
+    /// Maps the facet field id and the docids for which this field exists
+    pub facet_id_exists_docids: Database<FieldIdCodec, CboRoaringBitmapCodec>,
+
     /// Maps the facet field id, level and the number with the docids that corresponds to it.
     pub facet_id_f64_docids: Database<FacetLevelValueF64Codec, CboRoaringBitmapCodec>,
     /// Maps the facet field id and the string with the original string and docids that corresponds to it.
@@ -134,7 +138,7 @@ impl Index {
     pub fn new<P: AsRef<Path>>(mut options: heed::EnvOpenOptions, path: P) -> Result<Index> {
         use db_name::*;
 
-        options.max_dbs(16);
+        options.max_dbs(17);
         unsafe { options.flag(Flags::MdbAlwaysFreePages) };
 
         let env = options.open(path)?;
@@ -152,6 +156,9 @@ impl Index {
         let word_prefix_position_docids = env.create_database(Some(WORD_PREFIX_POSITION_DOCIDS))?;
         let facet_id_f64_docids = env.create_database(Some(FACET_ID_F64_DOCIDS))?;
         let facet_id_string_docids = env.create_database(Some(FACET_ID_STRING_DOCIDS))?;
+        let facet_id_exists_docids: Database<FieldIdCodec, CboRoaringBitmapCodec> =
+            env.create_database(Some(FACET_ID_EXISTS_DOCIDS))?;
+
         let field_id_docid_facet_f64s = env.create_database(Some(FIELD_ID_DOCID_FACET_F64S))?;
         let field_id_docid_facet_strings =
             env.create_database(Some(FIELD_ID_DOCID_FACET_STRINGS))?;
@@ -174,6 +181,7 @@ impl Index {
             field_id_word_count_docids,
             facet_id_f64_docids,
             facet_id_string_docids,
+            facet_id_exists_docids,
             field_id_docid_facet_f64s,
             field_id_docid_facet_strings,
             documents,
@@ -806,6 +814,18 @@ impl Index {
         }
     }
 
+    /// Retrieve all the documents which contain this field id
+    pub fn exists_faceted_documents_ids(
+        &self,
+        rtxn: &RoTxn,
+        field_id: FieldId,
+    ) -> heed::Result<RoaringBitmap> {
+        match self.facet_id_exists_docids.get(rtxn, &field_id)? {
+            Some(docids) => Ok(docids),
+            None => Ok(RoaringBitmap::new()),
+        }
+    }
+
     /* distinct field */
 
     pub(crate) fn put_distinct_field(

milli/src/update/clear_documents.rs

@@ -30,6 +30,7 @@ impl<'t, 'u, 'i> ClearDocuments<'t, 'u, 'i> {
             word_prefix_position_docids,
             facet_id_f64_docids,
             facet_id_string_docids,
+            facet_id_exists_docids,
             field_id_docid_facet_f64s,
             field_id_docid_facet_strings,
             documents,
@@ -69,6 +70,7 @@ impl<'t, 'u, 'i> ClearDocuments<'t, 'u, 'i> {
         field_id_word_count_docids.clear(self.wtxn)?;
         word_prefix_position_docids.clear(self.wtxn)?;
         facet_id_f64_docids.clear(self.wtxn)?;
+        facet_id_exists_docids.clear(self.wtxn)?;
         facet_id_string_docids.clear(self.wtxn)?;
         field_id_docid_facet_f64s.clear(self.wtxn)?;
         field_id_docid_facet_strings.clear(self.wtxn)?;

milli/src/update/delete_documents.rs

@@ -170,6 +170,7 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
             word_position_docids,
             word_prefix_position_docids,
             facet_id_f64_docids,
+            facet_id_exists_docids,
             facet_id_string_docids,
             field_id_docid_facet_f64s,
             field_id_docid_facet_strings,
@@ -424,11 +425,17 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
         }
 
         // We delete the documents ids that are under the facet field id values.
-        remove_docids_from_facet_field_id_number_docids(
+        remove_docids_from_facet_field_id_docids(
             self.wtxn,
             facet_id_f64_docids,
             &self.to_delete_docids,
         )?;
+        // We delete the documents ids that are under the facet field id values.
+        remove_docids_from_facet_field_id_docids(
+            self.wtxn,
+            facet_id_exists_docids,
+            &self.to_delete_docids,
+        )?;
 
         remove_docids_from_facet_field_id_string_docids(
             self.wtxn,
@@ -618,7 +625,7 @@ fn remove_docids_from_facet_field_id_string_docids<'a, C, D>(
     Ok(())
 }
 
-fn remove_docids_from_facet_field_id_number_docids<'a, C>(
+fn remove_docids_from_facet_field_id_docids<'a, C>(
     wtxn: &'a mut heed::RwTxn,
     db: &heed::Database<C, CboRoaringBitmapCodec>,
     to_remove: &RoaringBitmap,

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

@@ -0,0 +1,42 @@
+use std::fs::File;
+use std::io;
+
+use heed::{BytesDecode, BytesEncode};
+
+use super::helpers::{
+    create_sorter, merge_cbo_roaring_bitmaps, sorter_into_reader, GrenadParameters,
+};
+use crate::heed_codec::facet::{FieldIdCodec, FieldIdDocIdCodec};
+use crate::Result;
+
+/// Extracts the documents ids where this field appears.
+///
+/// Returns a grenad reader whose key is the field id encoded
+/// with `FieldIdCodec` and the value is a document_id (u32)
+/// encoded as native-endian bytes.
+#[logging_timer::time]
+pub fn extract_facet_exists_docids<R: io::Read + io::Seek>(
+    docid_fid_facet_number: grenad::Reader<R>,
+    indexer: GrenadParameters,
+) -> Result<grenad::Reader<File>> {
+    let max_memory = indexer.max_memory_by_thread();
+
+    let mut facet_exists_docids_sorter = create_sorter(
+        merge_cbo_roaring_bitmaps,
+        indexer.chunk_compression_type,
+        indexer.chunk_compression_level,
+        indexer.max_nb_chunks,
+        max_memory,
+    );
+
+    let mut cursor = docid_fid_facet_number.into_cursor()?;
+    while let Some((key_bytes, _)) = cursor.move_on_next()? {
+        let (field_id, document_id) = FieldIdDocIdCodec::bytes_decode(key_bytes).unwrap();
+
+        let key_bytes = FieldIdCodec::bytes_encode(&field_id).unwrap();
+
+        facet_exists_docids_sorter.insert(key_bytes, document_id.to_ne_bytes())?;
+    }
+
+    sorter_into_reader(facet_exists_docids_sorter, indexer)
+}

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

@@ -20,7 +20,7 @@ pub fn extract_fid_docid_facet_values<R: io::Read + io::Seek>(
     obkv_documents: grenad::Reader<R>,
     indexer: GrenadParameters,
     faceted_fields: &HashSet<FieldId>,
-) -> Result<(grenad::Reader<File>, grenad::Reader<File>)> {
+) -> Result<(grenad::Reader<File>, grenad::Reader<File>, grenad::Reader<File>)> {
     let max_memory = indexer.max_memory_by_thread();
 
     let mut fid_docid_facet_numbers_sorter = create_sorter(
@@ -28,7 +28,7 @@ pub fn extract_fid_docid_facet_values<R: io::Read + io::Seek>(
         indexer.chunk_compression_type,
         indexer.chunk_compression_level,
         indexer.max_nb_chunks,
-        max_memory.map(|m| m / 2),
+        max_memory.map(|m| m / 3),
     );
 
     let mut fid_docid_facet_strings_sorter = create_sorter(
@@ -36,7 +36,15 @@ pub fn extract_fid_docid_facet_values<R: io::Read + io::Seek>(
         indexer.chunk_compression_type,
         indexer.chunk_compression_level,
         indexer.max_nb_chunks,
-        max_memory.map(|m| m / 2),
+        max_memory.map(|m| m / 3),
+    );
+
+    let mut fid_docid_facet_exists_sorter = create_sorter(
+        keep_first,
+        indexer.chunk_compression_type,
+        indexer.chunk_compression_level,
+        indexer.max_nb_chunks,
+        max_memory.map(|m| m / 3),
     );
 
     let mut key_buffer = Vec::new();
@@ -46,15 +54,19 @@ pub fn extract_fid_docid_facet_values<R: io::Read + io::Seek>(
 
         for (field_id, field_bytes) in obkv.iter() {
             if faceted_fields.contains(&field_id) {
-                let value =
-                    serde_json::from_slice(field_bytes).map_err(InternalError::SerdeJson)?;
-                let (numbers, strings) = extract_facet_values(&value);
-
                 key_buffer.clear();
 
+                // here, we know already that the document must be added to the “field id exists” database
                 // prefix key with the field_id and the document_id
+
                 key_buffer.extend_from_slice(&field_id.to_be_bytes());
                 key_buffer.extend_from_slice(&docid_bytes);
+                fid_docid_facet_exists_sorter.insert(&key_buffer, ().as_bytes())?;
+
+                let value =
+                    serde_json::from_slice(field_bytes).map_err(InternalError::SerdeJson)?;
+
+                let (numbers, strings) = extract_facet_values(&value);
 
                 // insert facet numbers in sorter
                 for number in numbers {
@@ -79,7 +91,8 @@ pub fn extract_fid_docid_facet_values<R: io::Read + io::Seek>(
 
     Ok((
         sorter_into_reader(fid_docid_facet_numbers_sorter, indexer.clone())?,
-        sorter_into_reader(fid_docid_facet_strings_sorter, indexer)?,
+        sorter_into_reader(fid_docid_facet_strings_sorter, indexer.clone())?,
+        sorter_into_reader(fid_docid_facet_exists_sorter, indexer)?,
     ))
 }
 

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

@@ -1,4 +1,5 @@
 mod extract_docid_word_positions;
+mod extract_facet_exists_docids;
 mod extract_facet_number_docids;
 mod extract_facet_string_docids;
 mod extract_fid_docid_facet_values;
@@ -16,6 +17,7 @@ use log::debug;
 use rayon::prelude::*;
 
 use self::extract_docid_word_positions::extract_docid_word_positions;
+use self::extract_facet_exists_docids::extract_facet_exists_docids;
 use self::extract_facet_number_docids::extract_facet_number_docids;
 use self::extract_facet_string_docids::extract_facet_string_docids;
 use self::extract_fid_docid_facet_values::extract_fid_docid_facet_values;
@@ -53,7 +55,7 @@ pub(crate) fn data_from_obkv_documents(
         })
         .collect::<Result<()>>()?;
 
-    let result: Result<(Vec<_>, (Vec<_>, Vec<_>))> = flattened_obkv_chunks
+    let result: Result<(Vec<_>, (Vec<_>, (Vec<_>, Vec<_>)))> = flattened_obkv_chunks
         .par_bridge()
         .map(|flattened_obkv_chunks| {
             send_and_extract_flattened_documents_data(
@@ -72,7 +74,10 @@ pub(crate) fn data_from_obkv_documents(
 
     let (
         docid_word_positions_chunks,
-        (docid_fid_facet_numbers_chunks, docid_fid_facet_strings_chunks),
+        (
+            docid_fid_facet_numbers_chunks,
+            (docid_fid_facet_strings_chunks, docid_fid_facet_exists_chunks),
+        ),
     ) = result?;
 
     spawn_extraction_task::<_, _, Vec<grenad::Reader<File>>>(
@@ -137,6 +142,15 @@ pub(crate) fn data_from_obkv_documents(
         TypedChunk::FieldIdFacetNumberDocids,
         "field-id-facet-number-docids",
     );
+    spawn_extraction_task::<_, _, Vec<grenad::Reader<File>>>(
+        docid_fid_facet_exists_chunks.clone(),
+        indexer.clone(),
+        lmdb_writer_sx.clone(),
+        extract_facet_exists_docids,
+        merge_cbo_roaring_bitmaps,
+        TypedChunk::FieldIdFacetExistsDocids,
+        "field-id-facet-exists-docids",
+    );
 
     Ok(())
 }
@@ -197,6 +211,7 @@ fn send_original_documents_data(
 /// - docid_word_positions
 /// - docid_fid_facet_numbers
 /// - docid_fid_facet_strings
+/// - docid_fid_facet_exists
 fn send_and_extract_flattened_documents_data(
     flattened_documents_chunk: Result<grenad::Reader<File>>,
     indexer: GrenadParameters,
@@ -208,8 +223,11 @@ fn send_and_extract_flattened_documents_data(
     stop_words: &Option<fst::Set<&[u8]>>,
     max_positions_per_attributes: Option<u32>,
 ) -> Result<(
+    grenad::Reader<CursorClonableMmap>,
+    (
         grenad::Reader<CursorClonableMmap>,
         (grenad::Reader<CursorClonableMmap>, grenad::Reader<CursorClonableMmap>),
+    ),
 )> {
     let flattened_documents_chunk =
         flattened_documents_chunk.and_then(|c| unsafe { as_cloneable_grenad(&c) })?;
@@ -250,8 +268,11 @@ fn send_and_extract_flattened_documents_data(
                 Ok(docid_word_positions_chunk)
             },
             || {
-                let (docid_fid_facet_numbers_chunk, docid_fid_facet_strings_chunk) =
+                let (
-                    extract_fid_docid_facet_values(
+                    docid_fid_facet_numbers_chunk,
+                    docid_fid_facet_strings_chunk,
+                    docid_fid_facet_exists_chunk,
+                ) = extract_fid_docid_facet_values(
                     flattened_documents_chunk.clone(),
                     indexer.clone(),
                     faceted_fields,
@@ -273,7 +294,13 @@ fn send_and_extract_flattened_documents_data(
                     docid_fid_facet_strings_chunk.clone(),
                 )));
 
-                Ok((docid_fid_facet_numbers_chunk, docid_fid_facet_strings_chunk))
+                let docid_fid_facet_exists_chunk =
+                    unsafe { as_cloneable_grenad(&docid_fid_facet_exists_chunk)? };
+
+                Ok((
+                    docid_fid_facet_numbers_chunk,
+                    (docid_fid_facet_strings_chunk, docid_fid_facet_exists_chunk),
+                ))
             },
         );
 

milli/src/update/index_documents/mod.rs

@@ -1931,4 +1931,153 @@ mod tests {
 
         assert_eq!(ids.len(), map.len());
     }
+
+    #[test]
+    fn index_documents_check_exists_database_reindex() {
+        let path = tempfile::tempdir().unwrap();
+        let mut options = EnvOpenOptions::new();
+        options.map_size(10 * 1024 * 1024); // 10 MB
+        let index = Index::new(options, &path).unwrap();
+
+        let mut wtxn = index.write_txn().unwrap();
+        let content = documents!([
+            {
+                "id": 0,
+                "colour": 0,
+            },
+            {
+                "id": 1,
+                "colour": []
+            },
+            {
+                "id": 2,
+                "colour": {}
+            },
+            {
+                "id": 3,
+                "colour": null
+            },
+            {
+                "id": 4,
+                "colour": [1]
+            },
+            {
+                "id": 5
+            },
+            {
+                "id": 6,
+                "colour": {
+                    "green": 1
+                }
+            }
+        ]);
+
+        let config = IndexerConfig::default();
+        let indexing_config = IndexDocumentsConfig::default();
+        let mut builder =
+            IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
+                .unwrap();
+        builder.add_documents(content).unwrap();
+        builder.execute().unwrap();
+
+        wtxn.commit().unwrap();
+
+        let mut wtxn = index.write_txn().unwrap();
+        let mut builder = update::Settings::new(&mut wtxn, &index, &config);
+
+        let faceted_fields = hashset!(S("colour"));
+        builder.set_filterable_fields(faceted_fields);
+        builder.execute(|_| ()).unwrap();
+        wtxn.commit().unwrap();
+
+        let rtxn = index.read_txn().unwrap();
+        let facets = index.faceted_fields(&rtxn).unwrap();
+        assert_eq!(facets, hashset!(S("colour"), S("colour.green")));
+
+        let colour_id = index.fields_ids_map(&rtxn).unwrap().id("colour").unwrap();
+        let colour_green_id = index.fields_ids_map(&rtxn).unwrap().id("colour.green").unwrap();
+
+        let bitmap_colour = index.facet_id_exists_docids.get(&rtxn, &colour_id).unwrap().unwrap();
+        assert_eq!(bitmap_colour.into_iter().collect::<Vec<_>>(), vec![0, 1, 2, 3, 4, 6]);
+
+        let bitmap_colour_green =
+            index.facet_id_exists_docids.get(&rtxn, &colour_green_id).unwrap().unwrap();
+        assert_eq!(bitmap_colour_green.into_iter().collect::<Vec<_>>(), vec![6]);
+    }
+
+    #[test]
+    fn index_documents_check_exists_database() {
+        let path = tempfile::tempdir().unwrap();
+        let mut options = EnvOpenOptions::new();
+        options.map_size(10 * 1024 * 1024); // 10 MB
+        let index = Index::new(options, &path).unwrap();
+
+        let config = IndexerConfig::default();
+
+        let mut wtxn = index.write_txn().unwrap();
+        let mut builder = update::Settings::new(&mut wtxn, &index, &config);
+
+        let faceted_fields = hashset!(S("colour"));
+        builder.set_filterable_fields(faceted_fields);
+        builder.execute(|_| ()).unwrap();
+        wtxn.commit().unwrap();
+
+        let content = documents!([
+            {
+                "id": 0,
+                "colour": 0,
+            },
+            {
+                "id": 1,
+                "colour": []
+            },
+            {
+                "id": 2,
+                "colour": {}
+            },
+            {
+                "id": 3,
+                "colour": null
+            },
+            {
+                "id": 4,
+                "colour": [1]
+            },
+            {
+                "id": 5
+            },
+            {
+                "id": 6,
+                "colour": {
+                    "green": 1
+                }
+            }
+        ]);
+
+        let indexing_config = IndexDocumentsConfig::default();
+
+        let mut wtxn = index.write_txn().unwrap();
+
+        let mut builder =
+            IndexDocuments::new(&mut wtxn, &index, &config, indexing_config.clone(), |_| ())
+                .unwrap();
+        builder.add_documents(content).unwrap();
+        builder.execute().unwrap();
+
+        wtxn.commit().unwrap();
+
+        let rtxn = index.read_txn().unwrap();
+        let facets = index.faceted_fields(&rtxn).unwrap();
+        assert_eq!(facets, hashset!(S("colour"), S("colour.green")));
+
+        let colour_id = index.fields_ids_map(&rtxn).unwrap().id("colour").unwrap();
+        let colour_green_id = index.fields_ids_map(&rtxn).unwrap().id("colour.green").unwrap();
+
+        let bitmap_colour = index.facet_id_exists_docids.get(&rtxn, &colour_id).unwrap().unwrap();
+        assert_eq!(bitmap_colour.into_iter().collect::<Vec<_>>(), vec![0, 1, 2, 3, 4, 6]);
+
+        let bitmap_colour_green =
+            index.facet_id_exists_docids.get(&rtxn, &colour_green_id).unwrap().unwrap();
+        assert_eq!(bitmap_colour_green.into_iter().collect::<Vec<_>>(), vec![6]);
+    }
 }

milli/src/update/index_documents/typed_chunk.rs

@@ -35,6 +35,7 @@ pub(crate) enum TypedChunk {
     WordPairProximityDocids(grenad::Reader<File>),
     FieldIdFacetStringDocids(grenad::Reader<File>),
     FieldIdFacetNumberDocids(grenad::Reader<File>),
+    FieldIdFacetExistsDocids(grenad::Reader<File>),
     GeoPoints(grenad::Reader<File>),
 }
 
@@ -146,6 +147,18 @@ pub(crate) fn write_typed_chunk_into_index(
             )?;
             is_merged_database = true;
         }
+        TypedChunk::FieldIdFacetExistsDocids(facet_id_exists_docids_iter) => {
+            append_entries_into_database(
+                facet_id_exists_docids_iter,
+                &index.facet_id_exists_docids,
+                wtxn,
+                index_is_empty,
+                |value, _buffer| Ok(value),
+                merge_cbo_roaring_bitmaps,
+            )
+            .unwrap();
+            is_merged_database = true;
+        }
         TypedChunk::WordPairProximityDocids(word_pair_proximity_docids_iter) => {
             append_entries_into_database(
                 word_pair_proximity_docids_iter,