[CP] advance scan bug fix

obdev · wyfanxiao · haitaoy · ob-robot · commit 6006e21fa93b · 2026-04-03T16:28:04.000Z
Co-authored-by: wyfanxiao &lt;wyfanxiao@163.com&gt;
Co-authored-by: haitaoy &lt;haitaoy3.14@gmail.com&gt;
diff --git a/src/storage/access/ob_multiple_scan_merge.cpp b/src/storage/access/ob_multiple_scan_merge.cpp
@@ -421,16 +421,7 @@ int ObMultipleScanMerge::advance_scan(const blocksstable::ObDatumRange &range)
   int ret = OB_SUCCESS;
   is_unprojected_row_valid_ = false;
   ObStoreRowIterator *iter = nullptr;
-  for (int64_t i = 0; OB_SUCC(ret) && i < iters_.count(); ++i) {
-    if (OB_ISNULL(iter = iters_.at(i))) {
-      ret = OB_ERR_UNEXPECTED;
-      STORAGE_LOG(WARN, "unexpected null iter", K(ret), K(i));
-    } else if (OB_FAIL(iter->advance_scan(range))) {
-      STORAGE_LOG(WARN, "failed to advance scan", K(ret), K(i), KPC(iter));
-    }
-  }
-  if (OB_FAIL(ret)) {
-  } else if (OB_LIKELY(rows_merger_ != nullptr && !rows_merger_->empty())) {
+  if (OB_LIKELY(rows_merger_ != nullptr && !rows_merger_->empty())) {
     if (OB_NOT_NULL(block_row_store_)) {
       block_row_store_->disable();
     }
@@ -440,6 +431,7 @@ int ObMultipleScanMerge::advance_scan(const blocksstable::ObDatumRange &range)
     const ObScanMergeLoserTreeItem *top_item = nullptr;
     blocksstable::ObDatumRowkey top_key;
     ObScanMergeLoserTreeItem item;
+    int64_t pop_iter_idx = 0;
     while (OB_SUCC(ret) && !rows_merger_->empty()) {
       if (OB_FAIL(rows_merger_->rebuild())) {
         LOG_WARN("failed to rebuild rows merger", K(ret), KPC(rows_merger_));
@@ -454,23 +446,26 @@ int ObMultipleScanMerge::advance_scan(const blocksstable::ObDatumRange &range)
         LOG_WARN("failed to compare top key", K(ret), K(top_key), K(range));
       } else if (cmp_ret > 0 || (0 == cmp_ret && range.is_left_closed())) {
         break;
+      } else if (FALSE_IT(pop_iter_idx = top_item->iter_idx_)) {
       } else if (OB_FAIL(rows_merger_->pop())) {
         STORAGE_LOG(WARN, "failed to pop rows merger", K(ret), KPC(rows_merger_));
-      } else if (FALSE_IT(iter = iters_.at(top_item->iter_idx_))) {
+      } else if (FALSE_IT(iter = iters_.at(pop_iter_idx))) {
+      } else if (OB_FAIL(iter->advance_scan(range))) {
+        STORAGE_LOG(WARN, "failed to advance scan for memtable iter", K(ret), K(pop_iter_idx), KP(iter));
       } else if (OB_FAIL(iter->get_next_row(item.row_))) {
         if (OB_ITER_END == ret) {
           ret = OB_SUCCESS;
         } else {
-          LOG_WARN("failed to get next row from iterator", K(ret), K(top_item), KPC(iter));
+          LOG_WARN("failed to get next row from iterator", K(ret), K(pop_iter_idx), KP(iter));
         }
       } else if (OB_ISNULL(item.row_)) {
         ret = OB_ERR_UNEXPECTED;
-        STORAGE_LOG(WARN, "get next row return NULL row", K(ret), "iter_index", top_item->iter_idx_);
-      } else if (FALSE_IT(item.iter_idx_ = top_item->iter_idx_)) {
+        STORAGE_LOG(WARN, "get next row return NULL row", K(ret), "iter_index", pop_iter_idx);
+      } else if (FALSE_IT(item.iter_idx_ = pop_iter_idx)) {
       } else if (OB_FAIL(rows_merger_->push(item))) {
         STORAGE_LOG(WARN, "loser tree push error", K(ret));
       } else {
-        STORAGE_LOG(DEBUG, "yuanzhe debug", K(consumer_cnt_), K(top_item->iter_idx_));
+        STORAGE_LOG(DEBUG, "yuanzhe debug", K(consumer_cnt_), K(pop_iter_idx), K(item));
       }
     }
     if (FAILEDx(rows_merger_->rebuild())) {
@@ -479,6 +474,18 @@ int ObMultipleScanMerge::advance_scan(const blocksstable::ObDatumRange &range)
       block_row_store_->enable();
     }
   }
+  for (int64_t i = 0; OB_SUCC(ret) && i < consumer_cnt_; ++i) {
+    const int64_t iter_idx = consumers_[i];
+    if (OB_UNLIKELY(iter_idx < 0 || iter_idx >= iters_.count())) {
+      ret = OB_ERR_UNEXPECTED;
+      STORAGE_LOG(WARN, "unexpected consumer iter idx", K(ret), K(iter_idx), K(i), K_(consumer_cnt), K(iters_.count()));
+    } else if (OB_ISNULL(iter = iters_.at(iter_idx))) {
+      ret = OB_ERR_UNEXPECTED;
+      STORAGE_LOG(WARN, "unexpected null iter", K(ret), K(iter_idx), K(i));
+    } else if (OB_FAIL(iter->advance_scan(range))) {
+      STORAGE_LOG(WARN, "failed to advance remaining iter", K(ret), K(iter_idx), KP(iter));
+    }
+  }
   return ret;
 }
 
