CreateQuery t (children 3)
 Identifier t
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration key (children 1)
    DataType UInt64
   ColumnDeclaration value (children 1)
    DataType String
 Storage definition (children 3)
  Function MergeTree (children 1)
   ExpressionList
  Identifier key
  Set
