[opt](merge-on-write) avoid to check delete bitmap while lookup rowke…

…y in some situation to reduce CPU cost

be/src/olap/base_tablet.cpp

@@ -441,7 +441,8 @@ Status BaseTablet::lookup_row_key(const Slice& encoded_key, TabletSchema* latest
  const std::vector<RowsetSharedPtr>& specified_rowsets,
  RowLocation* row_location, uint32_t version,
  std::vector<std::unique_ptr<SegmentCacheHandle>>& segment_caches,
- RowsetSharedPtr* rowset, bool with_rowid) {
+ RowsetSharedPtr* rowset, bool with_rowid,
+ bool is_partial_update) {
  SCOPED_BVAR_LATENCY(g_tablet_lookup_rowkey_latency);
  size_t seq_col_length = 0;
  // use the latest tablet schema to decide if the tablet has sequence column currently
@@ -458,6 +459,8 @@ Status BaseTablet::lookup_row_key(const Slice& encoded_key, TabletSchema* latest
  Slice(encoded_key.get_data(), encoded_key.get_size() - seq_col_length - rowid_length);
  RowLocation loc;
 
+ bool need_to_check_delete_bitmap = is_partial_update || with_seq_col;
+
  for (size_t i = 0; i < specified_rowsets.size(); i++) {
  auto& rs = specified_rowsets[i];
  auto& segments_key_bounds = rs->rowset_meta()->get_segments_key_bounds();
@@ -496,16 +499,21 @@ Status BaseTablet::lookup_row_key(const Slice& encoded_key, TabletSchema* latest
  if (!s.ok() && !s.is<KEY_ALREADY_EXISTS>()) {
  return s;
  }
- if (s.ok() && _tablet_meta->delete_bitmap().contains_agg_without_cache(
- {loc.rowset_id, loc.segment_id, version}, loc.row_id)) {
- // if has sequence col, we continue to compare the sequence_id of
- // all rowsets, util we find an existing key.
- if (schema->has_sequence_col()) {
- continue;
+ if (s.ok() && need_to_check_delete_bitmap) {
+ // check if the key is already mark deleted
+ if (_tablet_meta->delete_bitmap().contains_agg_without_cache(
+ {loc.rowset_id, loc.segment_id, version}, loc.row_id)) {
+ // if has sequence col, we continue to compare the sequence_id of
+ // all rowsets, util we find an existing key.
+ if (with_seq_col) {
+ continue;
+ }
+ // The key is deleted, we need to break the loop and return
+ // KEY_NOT_FOUND.
+ break;
  }
- // The key is deleted, we don't need to search for it any more.
- break;
  }
+
  // `st` is either OK or KEY_ALREADY_EXISTS now.
  // for partial update, even if the key is already exists, we still need to
  // read it's original values to keep all columns align.
@@ -661,7 +669,8 @@ Status BaseTablet::calc_segment_delete_bitmap(RowsetSharedPtr rowset,
 
  RowsetSharedPtr rowset_find;
  auto st = lookup_row_key(key, rowset_schema.get(), true, specified_rowsets, &loc,
- dummy_version.first - 1, segment_caches, &rowset_find);
+ dummy_version.first - 1, segment_caches, &rowset_find, false,
+ is_partial_update);
  bool expected_st = st.ok() || st.is<KEY_NOT_FOUND>() || st.is<KEY_ALREADY_EXISTS>();
  // It's a defensive DCHECK, we need to exclude some common errors to avoid core-dump
  // while stress test

be/src/olap/base_tablet.h

@@ -153,7 +153,8 @@ class BaseTablet {
  const std::vector<RowsetSharedPtr>& specified_rowsets,
  RowLocation* row_location, uint32_t version,
  std::vector<std::unique_ptr<SegmentCacheHandle>>& segment_caches,
- RowsetSharedPtr* rowset = nullptr, bool with_rowid = true);
+ RowsetSharedPtr* rowset = nullptr, bool with_rowid = true,
+ bool is_partial_update = false);
 
  // calc delete bitmap when flush memtable, use a fake version to calc
  // For example, cur max version is 5, and we use version 6 to calc but