From 8f647b817f78edf002c64b36014ae4e46fa4133a Mon Sep 17 00:00:00 2001
From: Pascal Seitz <pascal.seitz@gmail.com>
Date: Wed, 28 Sep 2022 17:43:58 +0800
Subject: [PATCH 1/2] fix docstore settings for temp docstore

fixes #1565
---
 src/indexer/segment_serializer.rs | 28 +++++++++++++++++-----------
 src/indexer/segment_writer.rs     |  3 ++-
 2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/src/indexer/segment_serializer.rs b/src/indexer/segment_serializer.rs
index 7cb5bf3f5..dee306bb3 100644
--- a/src/indexer/segment_serializer.rs
+++ b/src/indexer/segment_serializer.rs
@@ -24,12 +24,25 @@ impl SegmentSerializer {
         // In the merge case this is not necessary because we can kmerge the already sorted
         // segments
         let remapping_required = segment.index().settings().sort_by_field.is_some() && !is_in_merge;
-        let store_component = if remapping_required {
-            SegmentComponent::TempStore
+        let settings = segment.index().settings().clone();
+        let store_writer = if remapping_required {
+            let store_write = segment.open_write(SegmentComponent::TempStore)?;
+            StoreWriter::new(
+                store_write,
+                crate::store::Compressor::None,
+                0, // we want random access on the docs, so we choose a minimal block size. Every
+                // doc will be flushed
+                settings.docstore_compress_dedicated_thread,
+            )?
         } else {
-            SegmentComponent::Store
+            let store_write = segment.open_write(SegmentComponent::Store)?;
+            StoreWriter::new(
+                store_write,
+                settings.docstore_compression,
+                settings.docstore_blocksize,
+                settings.docstore_compress_dedicated_thread,
+            )?
         };
-        let store_write = segment.open_write(store_component)?;
 
         let fast_field_write = segment.open_write(SegmentComponent::FastFields)?;
         let fast_field_serializer = CompositeFastFieldSerializer::from_write(fast_field_write)?;
@@ -38,13 +51,6 @@ impl SegmentSerializer {
         let fieldnorms_serializer = FieldNormsSerializer::from_write(fieldnorms_write)?;
 
         let postings_serializer = InvertedIndexSerializer::open(&mut segment)?;
-        let settings = segment.index().settings();
-        let store_writer = StoreWriter::new(
-            store_write,
-            settings.docstore_compression,
-            settings.docstore_blocksize,
-            settings.docstore_compress_dedicated_thread,
-        )?;
         Ok(SegmentSerializer {
             segment,
             store_writer,
diff --git a/src/indexer/segment_writer.rs b/src/indexer/segment_writer.rs
index 3ac64bc6c..9859beaee 100644
--- a/src/indexer/segment_writer.rs
+++ b/src/indexer/segment_writer.rs
@@ -393,7 +393,8 @@ fn remap_and_write(
             serializer
                 .segment()
                 .open_read(SegmentComponent::TempStore)?,
-            50,
+            1, /* The docstore is configured for tiny docs for fast random access, we don't need
+                * the the cache */
         )?;
         for old_doc_id in doc_id_map.iter_old_doc_ids() {
             let doc_bytes = store_read.get_document_bytes(old_doc_id)?;

From f8686ab1ec9cc456441aa185d20039e49f615a1c Mon Sep 17 00:00:00 2001
From: PSeitz <PSeitz@users.noreply.github.com>
Date: Fri, 30 Sep 2022 04:00:47 +0200
Subject: [PATCH 2/2] improve comments

Co-authored-by: Paul Masurel <paul@quickwit.io>
---
 src/indexer/segment_serializer.rs | 2 +-
 src/indexer/segment_writer.rs     | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/indexer/segment_serializer.rs b/src/indexer/segment_serializer.rs
index dee306bb3..dab5095df 100644
--- a/src/indexer/segment_serializer.rs
+++ b/src/indexer/segment_serializer.rs
@@ -31,7 +31,7 @@ impl SegmentSerializer {
                 store_write,
                 crate::store::Compressor::None,
                 0, // we want random access on the docs, so we choose a minimal block size. Every
-                // doc will be flushed
+                // doc will get its own block.
                 settings.docstore_compress_dedicated_thread,
             )?
         } else {
diff --git a/src/indexer/segment_writer.rs b/src/indexer/segment_writer.rs
index 9859beaee..91347d0d1 100644
--- a/src/indexer/segment_writer.rs
+++ b/src/indexer/segment_writer.rs
@@ -393,8 +393,8 @@ fn remap_and_write(
             serializer
                 .segment()
                 .open_read(SegmentComponent::TempStore)?,
-            1, /* The docstore is configured for tiny docs for fast random access, we don't need
-                * the the cache */
+            1, /* The docstore is configured to have one doc per block, and each doc is accessed
+                * only once: we don't need caching. */
         )?;
         for old_doc_id in doc_id_map.iter_old_doc_ids() {
             let doc_bytes = store_read.get_document_bytes(old_doc_id)?;