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[opt](merge-on-write) avoid to check delete bitmap while lookup rowkey in some situation to reduce CPU cost (#41480) #41439

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Merged
dataroaring merged 1 commit into from
Oct 11, 2024
Merged

[opt](merge-on-write) avoid to check delete bitmap while lookup rowkey in some situation to reduce CPU cost (#41480) #41439

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27 changes: 17 additions & 10 deletions be/src/olap/tablet.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2822,7 +2822,7 @@ Status Tablet::lookup_row_key(const Slice& encoded_key, TabletSchema* latest_sch
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
Expand All @@ -2839,6 +2839,8 @@ Status Tablet::lookup_row_key(const Slice& encoded_key, TabletSchema* latest_sch
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();
Expand Down Expand Up @@ -2877,15 +2879,19 @@ Status Tablet::lookup_row_key(const Slice& encoded_key, TabletSchema* latest_sch
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
Expand Down Expand Up @@ -3052,7 +3058,8 @@ Status Tablet::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
Expand Down
3 changes: 2 additions & 1 deletion be/src/olap/tablet.h
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Expand Up @@ -438,7 +438,8 @@ class Tablet final : public 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);

// Lookup a row with TupleDescriptor and fill Block
Status lookup_row_data(const Slice& encoded_key, const RowLocation& row_location,
Expand Down