Oracle Database Administration II flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

CONFIGURE RETENTION POLICY

An RMAN setting that defines which backups are obsolete. RECOVERY WINDOW n DAYS retains everything needed to recover to any point in the last n days; REDUNDANCY n keeps n copies of each file.

Block change tracking

A feature enabled with ALTER DATABASE ENABLE BLOCK CHANGE TRACKING that records changed blocks in a file maintained by CTWR, letting RMAN level 1 backups read only changed blocks and skip unchanged ones.

Incremental level 1 cumulative

An RMAN incremental backup that contains all blocks changed since the most recent level 0 backup, ignoring intermediate level 1 backups. It needs less redo during recovery than a differential level 1.

BACKUP PLUS ARCHIVELOG

An RMAN command that archives the current log, backs up archived logs, then backs up datafiles. The resulting backupset is consistent and recoverable without a separate archived log backup command.

Restore vs recover

RESTORE copies files from backup to disk. RECOVER applies archived and online redo to those files to reach a consistent SCN. A restore alone leaves files at an older point in time.

OPEN RESETLOGS requirement

Incomplete recovery, recovery to a point before the current log sequence, and Flashback Database all end with OPEN RESETLOGS. It creates a new incarnation and invalidates prior archived logs for future recovery.

TSPITR auxiliary instance

Tablespace point-in-time recovery creates an auxiliary instance, restores and recovers the chosen tablespace to a target time there, then moves recovered objects back using export/import or transportable tablespaces.

CROSSCHECK versus DELETE EXPIRED

CROSSCHECK verifies that backups recorded in the repository still exist on disk or tape and marks missing ones expired. DELETE EXPIRED removes those expired records; DELETE OBSOLETE removes backups violating retention.

BLOCKRECOVER command

An RMAN command that restores and recovers individual corrupt blocks from a backup or flashback log while the database remains open, using the current datafile as the base for recovery.

Flashback Query undo dependency

Flashback Query with AS OF TIMESTAMP or SCN reads past row versions from undo. It succeeds only if undo retention covers the target time; it never modifies data and needs no backup.

Flashback Table row movement

Flashback Table returns a table to a past point using undo. It requires ROW MOVEMENT to be enabled on the table and cannot recover a dropped table; Flashback Drop handles that case.

Guaranteed restore point

A restore point created with GUARANTEE FLASHBACK DATABASE that prevents deletion of flashback logs needed to reach it. It ensures Flashback Database can always return to that point.

Flashback Data Archive

A long-term row history repository configured with CREATE FLASHBACK ARCHIVE. It records changes in its own tablespace independent of undo retention, unlike Flashback Query, which depends on undo.

Data Recovery Advisor commands

LIST FAILURE shows detected failures, ADVISE FAILURE generates a repair script, and REPAIR FAILURE executes it. It operates only when the database is mounted or open and fixes only known failure types.

PDB$SEED restrictions

The seed PDB is a read-only template used by CREATE PLUGGABLE DATABASE FROM PDB$SEED. It cannot be modified or dropped, and it must stay read-only for cloning to work.

Common user naming rule

A common user is created in the CDB root with a C## prefix and can connect to any PDB. Local users, created inside a PDB without that prefix, are visible only in their own PDB.

Local undo in a PDB

When LOCAL UNDO is enabled, each PDB has its own undo tablespace instead of sharing the root's. This supports PDB cloning, unplugging, and point-in-time recovery without affecting other PDBs.

PDB open modes

ALTER PLUGGABLE DATABASE pdb OPEN opens a PDB for user connections. OPEN READ ONLY permits queries only, OPEN RESTRICTED allows restricted sessions, and MOUNTED blocks user connections but allows maintenance.

PDB SAVE STATE

ALTER PLUGGABLE DATABASE pdb SAVE STATE records the PDB's current open mode so it is restored automatically when the CDB restarts, avoiding manual reopening of each PDB.

Unplugging a PDB

ALTER PLUGGABLE DATABASE pdb UNPLUG INTO file writes an XML manifest describing the PDB. The PDB is removed from the CDB and can be plugged elsewhere with CREATE PLUGGABLE DATABASE USING manifest.

PDB snapshot clone

CREATE PLUGGABLE DATABASE ... SNAPSHOT COPY clones a read-only PDB using storage-level snapshots rather than copying datafiles. It is fast but requires storage support for snapshots.

CDB resource plan

A plan created in the CDB root with DBMS_RESOURCE_MANAGER that allocates shares, utilization limits, and parallel server limits per PDB. It is activated with ALTER SYSTEM SET RESOURCE_MANAGER_PLAN.

PDB lockdown profile

A profile that restricts operations such as ALTER SYSTEM or access to certain packages for a PDB. It is assigned with ALTER PLUGGABLE DATABASE ... SET LOCKDOWN PROFILE.

Transportable tablespace prerequisites

Source and target must share database and national character sets and compatible endianness, or datafiles must be converted with RMAN CONVERT TABLESPACE. The tablespace is made read-only before export.

RMAN CONVERT TABLESPACE

An RMAN command that converts tablespace datafiles for a different-endianness platform during transport. CONVERT DATAFILE performs the same conversion for individual files.

Full transportable export

A Data Pump export with FULL=Y and TRANSPORTABLE=Y that moves an entire database, including SYSTEM and SYSAUX tablespaces, using datafile transport and RMAN conversion when platforms differ.

AWR snapshot storage

AWR snapshots are persisted in the SYSAUX tablespace and controlled by STATISTICS_LEVEL. Reports are generated with awrrpt.sql or through DBMS_WORKLOAD_REPOSITORY procedures.

ASH sampling purpose

Active Session History samples active sessions every second into V$ACTIVE_SESSION_HISTORY, enabling top-event and blocking analysis. Persisted samples are queried in DBA_HIST_ACTIVE_SESS_HISTORY.

SQL plan baseline

A set of accepted execution plans managed by DBMS_SPM that prevents plan regressions. New plans are added from the cursor cache or tuning sets and evolved with EVOLVE_SQL_PLAN_BASELINE.

Real-time SQL monitoring

V$SQL_MONITOR tracks statements that run long or consume significant resources, showing per-operation progress. DBMS_SQLTUNE.REPORT_SQL_MONITOR renders the collected monitoring data as a report.

OTHER_GROUPS requirement

Every Resource Manager plan must include the OTHER_GROUPS consumer group. Sessions not matched by any mapping rule are assigned to it, so omitting it makes the plan invalid.

Maintenance window group

MAINTENANCE_WINDOW_GROUP defines the time windows when automated maintenance tasks such as AWR, ADDM, Automatic SQL Tuning, and Segment Advisor run. DBMS_AUTO_TASK_ADMIN enables or disables them.