U

Undo Advisor

A tool within the Oracle advisory framework that uses past undo usage to recommend settings for the UNDO_RETENTION parameter as well as an optimal size for the undo tablespace.

undo data

The record of changes to database blocks recorded in the undo tablespace to facilitate reverting the effect of an insert, update, or delete operation on the block.

Unicode

A universal encoded character set that allows you to store information from any known written language. Unicode provides a unique code value for every character, regardless of the platform, program, or language.

Unicode code point

A unique value assigned to every character in a Unicode character set.

Unicode datatype

Oracle datatypes used to store Unicode data when the database uses a non-Unicode character set by default. These datatypes include NCHAR, NVARCHAR, and NCLOB.

UNTIL CANCEL

A user-managed incomplete recovery command that uses a random point determined by the administrator to designate the stopping point in the incomplete recovery process.

UNTIL CHANGE

A user-managed incomplete recovery using the ALTER DATABASE command that uses the SCN to designate the stopping point in the incomplete recovery process.

UNTIL SCN

A Recovery Manager (RMAN)-based incomplete recovery command that uses an SCN to designate the stopping point in the incomplete recovery process.

UNTIL SEQUENCE

A Recovery Manager (RMAN)-based incomplete recovery command that uses a redo log sequence to designate the stopping point in the incomplete recovery process.

UNTIL TIME

A user-managed and Recovery Manager (RMAN)-based incomplete recovery command that uses time to designate the stopping point in the incomplete recovery process.

USER_DUMP_DEST

An initialization parameter used to specify the location of the user process trace files.

user error

An error introduced to the database by the user. This error often must be resolved with unique techniques such as incomplete recovery, the Log Miner utility, or database exports. The flashback database is well suited for recovering from user errors.

user-managed backups

Customized scripts that interact with the operating system's capabilities to copy and save files for later access.

user-managed recovery

The traditional non-Recovery Manager (RMAN) recovery where the DBA directly manages the database files required to recover the database.