CreateQuery functional_index_mergetree (children 3)
 Identifier functional_index_mergetree
 Columns definition (children 1)
  ExpressionList (children 1)
   ColumnDeclaration x (children 1)
    DataType Float64
 Storage definition (children 2)
  Function MergeTree
  Function round (children 1)
   ExpressionList (children 1)
    Identifier x
