diff --git a/planner/core/integration_test.go b/planner/core/integration_test.go
index e2cd9a55b4872..38048d4d30009 100644
--- a/planner/core/integration_test.go
+++ b/planner/core/integration_test.go
@@ -5118,13 +5118,13 @@ func (s *testIntegrationSuite) TestIndexMergeWarning(c *C) {
 	tk.MustExec("drop table if exists t1")
 	tk.MustExec("create table t1(c1 int, c2 int)")
 	tk.MustExec("select /*+ use_index_merge(t1) */ * from t1 where c1 < 1 or c2 < 1")
-	warningMsg := "Warning 1105 IndexMerge is inapplicable or disabled. No available filter or access path."
+	warningMsg := "Warning 1105 IndexMerge is inapplicable or disabled. No available filter or available index."
 	tk.MustQuery("show warnings").Check(testkit.Rows(warningMsg))
 
 	tk.MustExec("drop table if exists t1")
 	tk.MustExec("create table t1(c1 int, c2 int, key(c1), key(c2))")
 	tk.MustExec("select /*+ use_index_merge(t1), no_index_merge() */ * from t1 where c1 < 1 or c2 < 1")
-	warningMsg = "Warning 1105 IndexMerge is inapplicable or disabled. Got no_index_merge hint or switcher is off."
+	warningMsg = "Warning 1105 IndexMerge is inapplicable or disabled. Got no_index_merge hint or tidb_enable_index_merge is off."
 	tk.MustQuery("show warnings").Check(testkit.Rows(warningMsg))
 
 	tk.MustExec("drop table if exists t1")
diff --git a/planner/core/stats.go b/planner/core/stats.go
index cf79f098e9ac2..4b7ac3e33d00a 100644
--- a/planner/core/stats.go
+++ b/planner/core/stats.go
@@ -453,11 +453,9 @@ func (ds *DataSource) DeriveStats(childStats []*property.StatsInfo, selfSchema *
 		ds.indexMergeHints = nil
 		var msg string
 		if !isPossibleIdxMerge {
-			msg = "No available filter or access path."
+			msg = "No available filter or available index."
 		} else if !sessionAndStmtPermission {
-			msg = "Got no_index_merge hint or switcher is off."
-		} else if !needConsiderIndexMerge {
-			msg = "Got index path or exprs that cannot be pushed."
+			msg = "Got no_index_merge hint or tidb_enable_index_merge is off."
 		} else if ds.tableInfo.TempTableType == model.TempTableLocal {
 			msg = "Cannot use IndexMerge on temporary table."
 		} else if readFromTableCache {
@@ -465,7 +463,7 @@ func (ds *DataSource) DeriveStats(childStats []*property.StatsInfo, selfSchema *
 		}
 		msg = fmt.Sprintf("IndexMerge is inapplicable or disabled. %s", msg)
 		stmtCtx.AppendWarning(errors.Errorf(msg))
-		logutil.BgLogger().Info(msg)
+		logutil.BgLogger().Debug(msg)
 	}
 	return ds.stats, nil
 }
@@ -483,7 +481,7 @@ func (ds *DataSource) generateAndPruneIndexMergePath(indexMergeConds []expressio
 	// With hints and without generated IndexMerge paths
 	if regularPathCount == len(ds.possibleAccessPaths) {
 		ds.indexMergeHints = nil
-		ds.ctx.GetSessionVars().StmtCtx.AppendWarning(errors.Errorf("IndexMerge is inapplicable or disabled"))
+		ds.ctx.GetSessionVars().StmtCtx.AppendWarning(errors.Errorf("IndexMerge is inapplicable."))
 		return nil
 	}
 	// Do not need to consider the regular paths in find_best_task().
diff --git a/planner/core/testdata/integration_suite_out.json b/planner/core/testdata/integration_suite_out.json
index 6c946cdac4d2d..c3bbda1ed3f2c 100644
--- a/planner/core/testdata/integration_suite_out.json
+++ b/planner/core/testdata/integration_suite_out.json
@@ -1332,7 +1332,7 @@
           "└─IndexRangeScan 20.00 cop[tikv] table:tt, index:a(a) range:[10,10], [20,20], keep order:false, stats:pseudo"
         ],
         "Warnings": [
-          "Warning 1105 IndexMerge is inapplicable or disabled"
+          "Warning 1105 IndexMerge is inapplicable."
         ]
       },
       {
@@ -1342,7 +1342,7 @@
           "└─IndexRangeScan 6666.67 cop[tikv] table:tt, index:a(a) range:[-inf,10), [15,15], (20,+inf], keep order:false, stats:pseudo"
         ],
         "Warnings": [
-          "Warning 1105 IndexMerge is inapplicable or disabled"
+          "Warning 1105 IndexMerge is inapplicable."
         ]
       }
     ]
diff --git a/session/session_test.go b/session/session_test.go
index 4602758eeaa28..d8694348ffe85 100644
--- a/session/session_test.go
+++ b/session/session_test.go
@@ -5419,7 +5419,7 @@ func (s *testSessionSuite) TestLocalTemporaryTableScan(c *C) {
 			"12 112 1012", "3 113 1003", "14 114 1014", "16 116 1016", "7 117 1007", "18 118 1018",
 		))
 
-		tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1105 IndexMerge is inapplicable or disabled"))
+		tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1105 IndexMerge is inapplicable or disabled. Cannot use IndexMerge on temporary table."))
 	}
 
 	doModify := func() {
@@ -5458,7 +5458,7 @@ func (s *testSessionSuite) TestLocalTemporaryTableScan(c *C) {
 			"3 113 1003", "14 114 1014", "7 117 9999", "18 118 1018", "12 132 1012",
 		))
 
-		tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1105 IndexMerge is inapplicable or disabled"))
+		tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1105 IndexMerge is inapplicable or disabled. Cannot use IndexMerge on temporary table."))
 	}
 
 	assertSelectAsUnModified()
diff --git a/table/tables/cache_test.go b/table/tables/cache_test.go
index 62e48ccd24c94..30a3c20c3af00 100644
--- a/table/tables/cache_test.go
+++ b/table/tables/cache_test.go
@@ -142,7 +142,7 @@ func TestCacheTableBasicScan(t *testing.T) {
 			"12 112 1012", "3 113 1003", "14 114 1014", "16 116 1016", "7 117 1007", "18 118 1018",
 		))
 
-		tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1105 IndexMerge is inapplicable or disabled"))
+		tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1105 IndexMerge is inapplicable or disabled. Cannot use IndexMerge on TableCache."))
 	}
 	assertSelect()