CreateQuery tab1_copy (children 3)
 Identifier tab1_copy
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration a1 (children 1)
    DataType Int32
   ColumnDeclaration b1 (children 1)
    DataType Int32
 Storage definition (children 2)
  Function MergeTree
  Identifier a1