CreateQuery check_system_tables (children 3)
 Identifier check_system_tables
 Columns definition (children 1)
  ExpressionList (children 3)
   ColumnDeclaration name1 (children 1)
    DataType UInt8
   ColumnDeclaration name2 (children 1)
    DataType UInt8
   ColumnDeclaration name3 (children 1)
    DataType UInt8
 Storage definition (children 5)
  Function MergeTree (children 1)
   ExpressionList
  Identifier name2
  Identifier name1
  Identifier name1
  Set