CreateQuery index_test (children 3)
 Identifier index_test
 Columns definition (children 1)
  ExpressionList (children 3)
   ColumnDeclaration x (children 1)
    DataType UInt32
   ColumnDeclaration y (children 1)
    DataType UInt32
   ColumnDeclaration z (children 1)
    DataType UInt32
 Storage definition (children 2)
  Function MergeTree
  Identifier x
