1 files changed, 7 insertions, 0 deletions
diff --git a/src/mongo/db/storage/storage_engine.h b/src/mongo/db/storage/storage_engine.h
index eb6f0025313..824a059bf89 100644
--- a/src/mongo/db/storage/storage_engine.h
+++ b/src/mongo/db/storage/storage_engine.h
@@ -60,6 +60,13 @@ struct StorageGlobalParams;
 class StorageEngine {
 public:
     /**
+     * This is the minimum valid timestamp; it can be used for reads that need to see all
+     * untimestamped data but no timestamped data. We cannot use 0 here because 0 means see all
+     * timestamped data.
+     */
+    static const uint64_t kMinimumTimestamp = 1;
+
+    /**
      * When the storage engine needs to know how much oplog to preserve for the sake of active
      * transactions, it executes a callback that returns either the oldest active transaction
      * timestamp, or boost::none if there is no active transaction, or an error if it fails.