An open row is a row that is currently known to the database, a row that is currently in effect in the database. It is a row that has not been (logically) deleted from the database or superseded by a row modification.
In a transaction-time table, an open row is a row with a transaction-time period that has an ending bound of UNTIL_CLOSED. When a new row is added to a table with transaction time, the ending bound of the transaction-time column period value is set to UNTIL_CLOSED, and the original row is considered to be open until the row is modified or deleted.
UNTIL_CLOSED has a value of TIMESTAMP '9999-12-31 23:59:59.999999+00:00'.
In a valid-time table, all rows are considered to be open. When a row is deleted from a valid-time table, the row is physically deleted from the database, rather than closed. See Valid Row.
In a bitemporal table, an open row is a row with a transaction-time period that has an ending bound of UNTIL_CLOSED. Open rows that are no longer valid in the valid-time dimension are considered history rows, even though they remain open in the transaction-time dimension. See History Row.