diff --git a/integration-test/src/test/java/org/apache/iotdb/relational/it/db/it/IoTDBMultiTAGsWithAttributesTableIT.java b/integration-test/src/test/java/org/apache/iotdb/relational/it/db/it/IoTDBMultiTAGsWithAttributesTableIT.java
index 1b293f75865c3..3f59c88c568f6 100644
--- a/integration-test/src/test/java/org/apache/iotdb/relational/it/db/it/IoTDBMultiTAGsWithAttributesTableIT.java
+++ b/integration-test/src/test/java/org/apache/iotdb/relational/it/db/it/IoTDBMultiTAGsWithAttributesTableIT.java
@@ -21,6 +21,8 @@
 
 import org.apache.iotdb.isession.SessionConfig;
 import org.apache.iotdb.it.env.EnvFactory;
+import org.apache.iotdb.it.env.cluster.ClusterConstant;
+import org.apache.iotdb.it.env.cluster.EnvUtils;
 import org.apache.iotdb.it.env.cluster.node.DataNodeWrapper;
 import org.apache.iotdb.it.framework.IoTDBTestRunner;
 import org.apache.iotdb.itbase.category.TableClusterIT;
@@ -53,6 +55,11 @@
 @Category({TableLocalStandaloneIT.class, TableClusterIT.class})
 public class IoTDBMultiTAGsWithAttributesTableIT {
   private static final String DATABASE_NAME = "db";
+  // Default heap of the test DataNodes (see DataNodeWrapper#initVMConfig).
+  private static final int DEFAULT_DATANODE_MAX_HEAP_SIZE_IN_MB = 256;
+  // fourTableJoinTest needs about 3.5 MB of operator memory per DataRegion. A 256 MB heap has
+  // about 16 MB of it, enough for about 4 regions; 128 MB of heap per region leaves a 2x margin.
+  private static final int DATANODE_HEAP_SIZE_PER_DATA_REGION_IN_MB = 128;
 
   private static final String[] sql1 =
       new String[] {
@@ -185,6 +192,22 @@ public class IoTDBMultiTAGsWithAttributesTableIT {
   @BeforeClass
   public static void setUp() throws Exception {
     EnvFactory.getEnv().getConfig().getDataNodeCommonConfig().setSortBufferSize(1024 * 1024L);
+    // The number of DataRegionGroups follows the CPU cores (0.5 per core), and with it the number
+    // of FragmentInstances of fourTableJoinTest, each reserving up to the 1 MB sort buffer. Scale
+    // the DataNode heap, and so its operator memory, with the regions. On a 4-core machine
+    // (2 regions) this keeps the default heap.
+    final int expectedDataRegionsPerDataNode =
+        Math.max(1, Runtime.getRuntime().availableProcessors() / 2);
+    EnvFactory.getEnv()
+        .getConfig()
+        .getDataNodeJVMConfig()
+        .setMaxHeapSize(
+            Math.max(
+                EnvUtils.getIntFromSysVar(
+                    ClusterConstant.DATANODE_MAX_HEAP_SIZE,
+                    DEFAULT_DATANODE_MAX_HEAP_SIZE_IN_MB,
+                    0),
+                expectedDataRegionsPerDataNode * DATANODE_HEAP_SIZE_PER_DATA_REGION_IN_MB));
     EnvFactory.getEnv().initClusterEnvironment();
     EnvFactory.getEnv()
         .getConfig()