CreateQuery mv_primary_key (children 4)
 Identifier mv_primary_key
 Columns definition (children 2)
  ExpressionList (children 1)
   ColumnDeclaration key (children 1)
    DataType String
  Identifier key
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 2)
    ExpressionList (children 1)
     Asterisk
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier data
 ViewTargets (children 1)
  Storage definition (children 1)
   Function MergeTree
