[feature] keep the order of GlobalLearnerList

deps/oblib/src/common/ob_learner_list.h

@@ -18,7 +18,6 @@
 #include "lib/string/ob_sql_string.h"         // ObSqlString
 #include "lib/utility/ob_unify_serialize.h"   // serialize
 #include "common/ob_member.h"
-#include <algorithm>
 
 namespace oceanbase
 {

deps/oblib/src/common/ob_learner_list.ipp

@@ -146,7 +146,8 @@ int BaseLearnerList<MAX_SIZE, T>::add_learner(const T &learner)
   } else if (OB_FAIL(learner_array_.push_back(learner))) {
     COMMON_LOG(ERROR, "learner_array_ push back failed", K(ret), K(learner));
   } else {
-    lib::ob_sort(learner_array_.begin(), learner_array_.end(), [](const T &a, const T &b){ return a < b;});
+    // For replication and migration of columnar replicas,
+    // learner_list should keep the order of learners as they had been added into.
   }
   return ret;
 }