diff --git a/kylin-spark-project/kylin-spark-query/src/main/scala/org/apache/kylin/query/pushdown/SparkSqlClient.scala b/kylin-spark-project/kylin-spark-query/src/main/scala/org/apache/kylin/query/pushdown/SparkSqlClient.scala
index a4064fec769..078b305da59 100644
--- a/kylin-spark-project/kylin-spark-query/src/main/scala/org/apache/kylin/query/pushdown/SparkSqlClient.scala
+++ b/kylin-spark-project/kylin-spark-query/src/main/scala/org/apache/kylin/query/pushdown/SparkSqlClient.scala
@@ -26,9 +26,7 @@ import org.apache.kylin.common.{KylinConfig, QueryContextFacade}
 import org.apache.kylin.engine.spark.metadata.cube.StructField
 import org.apache.kylin.query.runtime.plans.QueryToExecutionIDCache
 import org.apache.spark.network.util.JavaUtils
-import org.apache.spark.sql.functions._
 import org.apache.spark.sql.hive.utils.{QueryMetricUtils, ResourceDetectUtils}
-import org.apache.spark.sql.types.StringType
 import org.apache.spark.sql.utils.SparkTypeUtil
 import org.apache.spark.sql.{DataFrame, SparkSession}
 import org.slf4j.{Logger, LoggerFactory}
@@ -75,15 +73,9 @@ object SparkSqlClient {
 		ss.sparkContext.setJobGroup(jobGroup,
 			"Pushdown Query Id: " + QueryContextFacade.current().getQueryId, interruptOnCancel = true)
 		try {
-			val temporarySchema = df.schema.fields.zipWithIndex.map {
-				case (_, index) => s"temporary_$index"
-			}
-			val tempDF = df.toDF(temporarySchema: _*)
-			val columns = tempDF.schema.map(tp => col(s"`${tp.name}`").cast(StringType))
-			val frame = tempDF.select(columns: _*)
-			val rowList = frame.collect().map(_.toSeq.map(_.asInstanceOf[String]).asJava).toSeq.asJava
+			val rowList = df.collect().map(_.toSeq.map(col => if (col == null) "" else col.toString).asJava).toSeq.asJava
 			val fieldList = df.schema.map(field => SparkTypeUtil.convertSparkFieldToJavaField(field)).asJava
-			val (scanRows, scanFiles, metadataTime, scanTime, scanBytes) = QueryMetricUtils.collectScanMetrics(frame.queryExecution.executedPlan)
+			val (scanRows, scanFiles, metadataTime, scanTime, scanBytes) = QueryMetricUtils.collectScanMetrics(df.queryExecution.executedPlan)
 			QueryContextFacade.current().addAndGetScannedRows(scanRows.asScala.map(Long2long(_)).sum)
 			QueryContextFacade.current().addAndGetScanFiles(scanFiles.asScala.map(Long2long(_)).sum)
 			QueryContextFacade.current().addAndGetScannedBytes(scanBytes.asScala.map(Long2long(_)).sum)