diff --git a/CHANGELOG.md b/CHANGELOG.md
index 68f578cdf2ec7..7c3c8ac41a16b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -122,6 +122,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Fix NPE in multiterms aggregations involving empty buckets ([#7318](https://github.com/opensearch-project/OpenSearch/pull/7318))
 - Precise system clock time in MasterService debug logs ([#7902](https://github.com/opensearch-project/OpenSearch/pull/7902))
 - Adds log4j configuration for telemetry LogSpanExporter ([#8393](https://github.com/opensearch-project/OpenSearch/pull/8393))
+- Improve indexing performance for flat_object type ([#7855](https://github.com/opensearch-project/OpenSearch/pull/7855))
 
 ### Security
 
diff --git a/modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/30_search.yml b/modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/30_search.yml
index 4b3d5bd9e2980..a006fde630716 100644
--- a/modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/30_search.yml
+++ b/modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/30_search.yml
@@ -482,100 +482,3 @@
                         }]
     - match: { error.root_cause.0.type: "illegal_argument_exception" }
     - match: { error.root_cause.0.reason: "script score function must not produce negative scores, but got: [-9.0]"}
-
----
-
-"Flat-object fields from within the scripting":
-  - skip:
-      version: " - 2.6.99"
-      reason: "flat_object is introduced in 2.7.0"
-
-  - do:
-      indices.create:
-        index: test
-        body:
-          mappings:
-            properties:
-              flat:
-                type : "flat_object"
-
-  # This document has 6 distinct parts in its flat_object field paths:
-  # - flat.field_1
-  # - flat.field_2
-  # - flat.field_3
-  # - flat.inner
-  # - flat.field_A
-  # - flat.field_B
-  - do:
-      index:
-        index: test
-        id:    1
-        body:  {
-          "flat": {
-            "field_1": "John Doe",
-            "field_2": 33,
-            "field_3": false,
-            "inner": {
-              "field_A": ["foo", "bar"],
-              "field_B": false
-            }
-          }
-        }
-
-  - do:
-      index:
-        index: test
-        id:    2
-        body:  {
-          "flat": {
-            "field_1": "Joe Public",
-            "field_2": 45
-          }
-        }
-
-  - do:
-      indices.refresh:
-        index: test
-
-  # It is possible to filter based on the number of distinct parts of flat_object field paths
-  - do:
-      search:
-        body: {
-          _source: true,
-          query: {
-            bool: {
-              filter: {
-                script: {
-                  script: {
-                    source: "doc['flat'].size() == 6",
-                    lang: "painless"
-                  }
-                }
-              }
-            }
-          }
-        }
-
-  - length:   { hits.hits: 1  }
-  - match: { hits.hits.0._source.flat.field_1: "John Doe" }
-
-  - do:
-      search:
-        body: {
-          _source: true,
-          query: {
-            bool: {
-              filter: {
-                script: {
-                  script: {
-                    source: "doc['flat'].size() < 6",
-                    lang: "painless"
-                  }
-                }
-              }
-            }
-          }
-        }
-
-  - length:   { hits.hits: 1  }
-  - match: { hits.hits.0._source.flat.field_1: "Joe Public" }
diff --git a/server/src/main/java/org/opensearch/index/mapper/FlatObjectFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/FlatObjectFieldMapper.java
index 36e0adbbf057f..f8206d138534d 100644
--- a/server/src/main/java/org/opensearch/index/mapper/FlatObjectFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/FlatObjectFieldMapper.java
@@ -659,21 +659,18 @@ private void parseValueAddFields(ParseContext context, String value, String fiel
             }
 
             if (fieldType().hasDocValues()) {
-                if (context.doc().getField(fieldType().name()) == null || !context.doc().getFields(fieldType().name()).equals(field)) {
-                    if (fieldName.equals(fieldType().name())) {
-                        context.doc().add(new SortedSetDocValuesField(fieldType().name(), binaryValue));
-                    }
-                    if (valueType.equals(VALUE_SUFFIX)) {
-                        if (valueFieldMapper != null) {
-                            context.doc().add(new SortedSetDocValuesField(fieldType().name() + VALUE_SUFFIX, binaryValue));
-                        }
+                if (fieldName.equals(fieldType().name())) {
+                    context.doc().add(new SortedSetDocValuesField(fieldType().name(), binaryValue));
+                }
+                if (valueType.equals(VALUE_SUFFIX)) {
+                    if (valueFieldMapper != null) {
+                        context.doc().add(new SortedSetDocValuesField(fieldType().name() + VALUE_SUFFIX, binaryValue));
                     }
-                    if (valueType.equals(VALUE_AND_PATH_SUFFIX)) {
-                        if (valueAndPathFieldMapper != null) {
-                            context.doc().add(new SortedSetDocValuesField(fieldType().name() + VALUE_AND_PATH_SUFFIX, binaryValue));
-                        }
+                }
+                if (valueType.equals(VALUE_AND_PATH_SUFFIX)) {
+                    if (valueAndPathFieldMapper != null) {
+                        context.doc().add(new SortedSetDocValuesField(fieldType().name() + VALUE_AND_PATH_SUFFIX, binaryValue));
                     }
-
                 }
             }