Tune the words prefixes threshold to compute for 1/1000 instead

Cargo.lock

@@ -866,6 +866,7 @@ dependencies = [
  "anyhow",
  "byte-unit",
  "heed",
+ "jemallocator",
  "milli",
  "stderrlog",
  "structopt",

infos/src/main.rs

@@ -598,7 +598,7 @@ fn export_documents(index: &Index, rtxn: &heed::RoTxn, internal_ids: Vec<u32>) -
     let fields_ids_map = index.fields_ids_map(rtxn)?;
     let displayed_fields: Vec<_> = fields_ids_map.iter().map(|(id, _name)| id).collect();
 
-    let iter: Box<Iterator<Item = _>> = if internal_ids.is_empty() {
+    let iter: Box<dyn Iterator<Item = _>> = if internal_ids.is_empty() {
         Box::new(index.documents.iter(rtxn)?.map(|result| {
             result.map(|(_id, obkv)| obkv)
         }))

milli/src/update/words_prefixes.rs

@@ -41,7 +41,7 @@ impl<'t, 'u, 'i> WordsPrefixes<'t, 'u, 'i> {
             chunk_fusing_shrink_size: None,
             max_nb_chunks: None,
             max_memory: None,
-            threshold: 0.01, // 1%
+            threshold: 0.1 / 100.0, // .01%
             max_prefix_length: 4,
             _update_id: update_id,
         }