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Limit prefetch depth in scan/multi-scan

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This commit is contained in:
DengzhiLiu
2023-02-09 17:26:39 +00:00
committed by ob-robot
parent 354b83cbb4
commit 345a5ef182
4 changed files with 29 additions and 4 deletions
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19
src/storage/access/ob_index_tree_prefetcher.cpp
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@ -674,6 +674,7 @@ void ObIndexTreeMultiPassPrefetcher::reset()
can_blockscan_ = false;
is_prefetch_end_ = false;
is_row_lock_checked_ = false;
need_check_prefetch_depth_ = false;
cur_range_fetch_idx_ = 0;
cur_range_prefetch_idx_ = 0;
max_range_prefetching_cnt_ = 0;
@ -699,6 +700,7 @@ void ObIndexTreeMultiPassPrefetcher::reuse()
clean_blockscan_check_info();
is_prefetch_end_ = false;
is_row_lock_checked_ = false;
need_check_prefetch_depth_ = false;
cur_range_fetch_idx_ = 0;
cur_range_prefetch_idx_ = 0;
cur_micro_data_fetch_idx_ = -1;
@ -816,6 +818,12 @@ int ObIndexTreeMultiPassPrefetcher::init_basic_info(
cur_level_ = 0;
iter_type_ = iter_type;
index_tree_height_ = sstable_->get_meta().get_index_tree_height();
need_check_prefetch_depth_ =
(ObStoreRowIterator::IteratorScan == iter_type || ObStoreRowIterator::IteratorMultiScan == iter_type) &&
iter_param_->limit_prefetch_ &&
nullptr != access_ctx_->limit_param_ &&
access_ctx_->limit_param_->limit_ >= 0 &&
access_ctx_->limit_param_->limit_ < 4096;
switch (iter_type) {
case ObStoreRowIterator::IteratorMultiGet: {
rowkeys_ = static_cast<const common::ObIArray<blocksstable::ObDatumRowkey> *> (query_range);
@ -982,6 +990,7 @@ int ObIndexTreeMultiPassPrefetcher::try_add_query_range(ObIndexTreeLevelHandle &
return ret;
}
static int32_t OB_SSTABLE_MICRO_AVG_COUNT = 100;
int ObIndexTreeMultiPassPrefetcher::prefetch_micro_data()
{
int ret = OB_SUCCESS;
@ -995,9 +1004,15 @@ int ObIndexTreeMultiPassPrefetcher::prefetch_micro_data()
} else {
int64_t prefetched_cnt = 0;
int64_t prefetch_micro_idx = 0;
prefetch_depth_ = min(max_micro_handle_cnt_, 2 * prefetch_depth_);
prefetch_depth_ = MIN(max_micro_handle_cnt_, 2 * prefetch_depth_);
if (need_check_prefetch_depth_) {
int64_t prefetch_micro_cnt = MAX(1,
(access_ctx_->limit_param_->offset_ + access_ctx_->limit_param_->limit_ - access_ctx_->out_cnt_ + \
OB_SSTABLE_MICRO_AVG_COUNT - 1) / OB_SSTABLE_MICRO_AVG_COUNT);
prefetch_depth_ = MIN(prefetch_depth_, prefetch_micro_cnt);
}
int64_t prefetch_depth = min(static_cast<int64_t>(prefetch_depth_),
max_micro_handle_cnt_ - (micro_data_prefetch_idx_ - cur_micro_data_fetch_idx_));
max_micro_handle_cnt_ - (micro_data_prefetch_idx_ - cur_micro_data_fetch_idx_));
while (OB_SUCC(ret) && prefetched_cnt < prefetch_depth) {
if (OB_FAIL(drill_down())) {
if (OB_UNLIKELY(OB_ITER_END != ret)) {