CreateQuery user_transactions (children 3)
 Identifier user_transactions
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration user_id (children 1)
    DataType UInt64
   ColumnDeclaration transaction_id (children 1)
    DataType String
 Storage definition (children 2)
  Function MergeTree
  Identifier user_id
