diff --git a/internal/util/importutil/import_util.go b/internal/util/importutil/import_util.go
index 56b629c2661b3..58b28494368d1 100644
--- a/internal/util/importutil/import_util.go
+++ b/internal/util/importutil/import_util.go
@@ -1024,7 +1024,7 @@ func splitFieldsData(collectionInfo *CollectionInfo, fieldsData BlockData, shard
 	rowIDField, ok := fieldsData[common.RowIDField]
 	if !ok {
 		rowIDField = &storage.Int64FieldData{
-			Data: make([]int64, 0),
+			Data: make([]int64, 0, rowCount),
 		}
 		fieldsData[common.RowIDField] = rowIDField
 	}
diff --git a/internal/util/importutil/import_wrapper.go b/internal/util/importutil/import_wrapper.go
index 730d0a024232c..d9199e334bab4 100644
--- a/internal/util/importutil/import_wrapper.go
+++ b/internal/util/importutil/import_wrapper.go
@@ -301,6 +301,7 @@ func (p *ImportWrapper) Import(filePaths []string, options ImportOptions) error
 			if err != nil {
 				return err
 			}
+			defer parser.Close()
 
 			err = parser.Parse()
 			if err != nil {
diff --git a/internal/util/importutil/parquet_column_reader.go b/internal/util/importutil/parquet_column_reader.go
index f0ebf41b08ca6..2b45444307284 100644
--- a/internal/util/importutil/parquet_column_reader.go
+++ b/internal/util/importutil/parquet_column_reader.go
@@ -208,7 +208,7 @@ func ReadBoolArrayData(pcr *ParquetColumnReader, count int64) ([][]bool, error)
 		offsets := listReader.Offsets()
 		for i := 1; i < len(offsets); i++ {
 			start, end := offsets[i-1], offsets[i]
-			elementData := make([]bool, 0)
+			elementData := make([]bool, 0, end-start)
 			for j := start; j < end; j++ {
 				elementData = append(elementData, boolReader.Value(int(j)))
 			}
@@ -306,7 +306,7 @@ func ReadStringArrayData(pcr *ParquetColumnReader, count int64) ([][]string, err
 		offsets := listReader.Offsets()
 		for i := 1; i < len(offsets); i++ {
 			start, end := offsets[i-1], offsets[i]
-			elementData := make([]string, 0)
+			elementData := make([]string, 0, end-start)
 			for j := start; j < end; j++ {
 				elementData = append(elementData, stringReader.Value(int(j)))
 			}
diff --git a/internal/util/importutil/parquet_parser.go b/internal/util/importutil/parquet_parser.go
index d7865046e289e..ab7356b2aca91 100644
--- a/internal/util/importutil/parquet_parser.go
+++ b/internal/util/importutil/parquet_parser.go
@@ -23,6 +23,7 @@ import (
 
 	"github.com/apache/arrow/go/v12/arrow"
 	"github.com/apache/arrow/go/v12/arrow/memory"
+	"github.com/apache/arrow/go/v12/parquet"
 	"github.com/apache/arrow/go/v12/parquet/file"
 	"github.com/apache/arrow/go/v12/parquet/pqarrow"
 	"go.uber.org/zap"
@@ -87,11 +88,15 @@ func NewParquetParser(ctx context.Context,
 		return nil, err
 	}
 
-	reader, err := file.NewParquetReader(cmReader)
+	reader, err := file.NewParquetReader(cmReader, file.WithReadProps(&parquet.ReaderProperties{
+		BufferSize:            32 * 1024 * 1024,
+		BufferedStreamEnabled: true,
+	}))
 	if err != nil {
 		log.Warn("create parquet reader failed", zap.Error(err))
 		return nil, err
 	}
+	log.Info("create file reader done!", zap.Int("row group num", reader.NumRowGroups()), zap.Int64("num rows", reader.NumRows()))
 
 	fileReader, err := pqarrow.NewFileReader(reader, pqarrow.ArrowReadProperties{}, memory.DefaultAllocator)
 	if err != nil {
@@ -544,7 +549,7 @@ func (p *ParquetParser) readData(columnReader *ParquetColumnReader, rowCount int
 			Dim:  columnReader.dimension,
 		}, nil
 	case schemapb.DataType_Array:
-		data := make([]*schemapb.ScalarField, 0)
+		data := make([]*schemapb.ScalarField, 0, rowCount)
 		switch columnReader.elementType {
 		case schemapb.DataType_Bool:
 			boolArray, err := ReadBoolArrayData(columnReader, rowCount)
diff --git a/internal/util/importutil/parquet_parser_test.go b/internal/util/importutil/parquet_parser_test.go
index e14cdef415b6e..ad498444c6ca1 100644
--- a/internal/util/importutil/parquet_parser_test.go
+++ b/internal/util/importutil/parquet_parser_test.go
@@ -474,7 +474,7 @@ func buildArrayData(dataType, elementType schemapb.DataType, dim, rows int, isBi
 
 func writeParquet(w io.Writer, milvusSchema *schemapb.CollectionSchema, numRows int) error {
 	schema := convertMilvusSchemaToArrowSchema(milvusSchema)
-	fw, err := pqarrow.NewFileWriter(schema, w, parquet.NewWriterProperties(), pqarrow.DefaultWriterProps())
+	fw, err := pqarrow.NewFileWriter(schema, w, parquet.NewWriterProperties(parquet.WithMaxRowGroupLength(1000)), pqarrow.DefaultWriterProps())
 	if err != nil {
 		return err
 	}