CreateQuery check_system_tables (children 3)
 Identifier check_system_tables
 Columns definition (children 1)
  ExpressionList (children 4)
   ColumnDeclaration date (children 1)
    DataType Date
   ColumnDeclaration value (children 1)
    DataType String
   ColumnDeclaration version (children 1)
    DataType UInt64
   ColumnDeclaration sign (children 1)
    DataType Int8
 Storage definition (children 4)
  Function VersionedCollapsingMergeTree (children 1)
   ExpressionList (children 2)
    Identifier sign
    Identifier version
  Identifier date
  Identifier date
  Set
