diff --git a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/cache/schema/DeviceLastCache.java b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/cache/schema/DeviceLastCache.java
index a2f7696b6dfb..36fc39c3286c 100644
--- a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/cache/schema/DeviceLastCache.java
+++ b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/cache/schema/DeviceLastCache.java
@@ -104,8 +104,7 @@ int initOrInvalidate(final String[] measurements, final boolean isInvalidate) {
             }
             if (Objects.isNull(tvPair)) {
               diff.addAndGet(
-                  (int) RamUsageEstimator.sizeOf(measurement)
-                      + (int) RamUsageEstimator.HASHTABLE_RAM_BYTES_PER_ENTRY);
+                  (int) RamUsageEstimator.sizeOf(measurement) + getTVPairEntrySize(newPair));
               return newPair;
             }
             return tvPair;
diff --git a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/cache/schema/DeviceNormalSchema.java b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/cache/schema/DeviceNormalSchema.java
index cfad9c9e45e0..5ce2ca06fcd5 100644
--- a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/cache/schema/DeviceNormalSchema.java
+++ b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/cache/schema/DeviceNormalSchema.java
@@ -88,7 +88,10 @@ private int putEntry(
     final SchemaCacheEntry putEntry = new SchemaCacheEntry(schema, tagMap);
     final SchemaCacheEntry cachedEntry = measurementMap.put(measurement, putEntry);
     return Objects.isNull(cachedEntry)
-        ? (int) (RamUsageEstimator.sizeOf(measurement) + SchemaCacheEntry.estimateSize(putEntry))
+        ? (int)
+            (RamUsageEstimator.sizeOf(measurement)
+                + SchemaCacheEntry.estimateSize(putEntry)
+                + RamUsageEstimator.HASHTABLE_RAM_BYTES_PER_ENTRY)
         : SchemaCacheEntry.estimateSize(putEntry) - SchemaCacheEntry.estimateSize(cachedEntry);
   }
 
@@ -101,7 +104,8 @@ public int estimateSize() {
                 entry ->
                     Math.toIntExact(
                         RamUsageEstimator.sizeOf(entry.getKey())
-                            + SchemaCacheEntry.estimateSize(entry.getValue())))
+                            + SchemaCacheEntry.estimateSize(entry.getValue())
+                            + RamUsageEstimator.HASHTABLE_RAM_BYTES_PER_ENTRY))
             .reduce(0, Integer::sum);
   }
 }