Heuristics for tail prefetch size

facebook · Apr 28, 2023 · ca7ff4e · ca7ff4e
1 parent 21722b6
commit ca7ff4e
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/table/block_based/block_based_table_reader.cc b/table/block_based/block_based_table_reader.cc
@@ -818,7 +818,8 @@ Status BlockBasedTable::PrefetchTail(
     // That's because we need to issue readahead before we read the
     // properties,
     // at which point we don't yet know the index type.
-    tail_prefetch_size = prefetch_all || preload_all ? 512 * 1024 : 4 * 1024;
+    tail_prefetch_size =
+        prefetch_all || preload_all ? 4 * 1024 + 0.01 * file_size : 4 * 1024;
     ROCKS_LOG_WARN(logger,
                    "Tail prefetch size %zu is calculated based on heuristics",
                    tail_prefetch_size);