Oracle 1Z0-076 flashcards

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

STARTUP NOMOUNT

Startup stage that reads the parameter file, allocates the SGA, and starts background processes without opening control files or datafiles. Used to create a database or recreate control files.

SHUTDOWN IMMEDIATE

Shutdown mode that disconnects all sessions, rolls back uncommitted transactions, and checkpoints datafiles before closing the database cleanly. No instance recovery is needed on next startup.

SHUTDOWN ABORT

Shutdown mode that terminates the instance immediately without checkpointing or rolling back transactions. The next startup performs instance recovery using online redo logs.

MOUNT stage

Startup stage in which the instance opens the control files to locate datafiles and redo logs, but datafiles remain closed. Required for operations such as enabling ARCHIVELOG mode or renaming datafiles.

ARCHIVELOG mode

Database mode in which filled online redo log groups are archived before reuse, enabling online backups and point-in-time recovery. Requires the database to be mounted, not open, when switching modes.

NOARCHIVELOG mode

Database mode in which online redo logs are overwritten without archiving. Consistent backups require the database to be shut down cleanly or mounted, and recovery is limited to the last full backup.

UNDO_RETENTION

Parameter specifying the desired time, in seconds, that committed undo data is retained to support Oracle Flashback Query and long-running queries. Honored only when undo space permits unless retention is guaranteed.

RETENTION GUARANTEE

Undo tablespace attribute that prevents Oracle from overwriting unexpired undo data. If the tablespace fills, transactions fail with ORA-30036 instead of reusing unexpired undo extents.

MEMORY_TARGET

Dynamic initialization parameter setting the total amount of shared memory available to the instance for SGA and PGA combined. When set, SGA_TARGET and PGA_AGGREGATE_TARGET are auto-tuned.

SGA_TARGET

Parameter defining the total size of the System Global Area when automatic shared memory management is used. Individual component sizes such as buffer cache and shared pool are then adjusted automatically.

PGA_AGGREGATE_TARGET

Parameter setting the target total PGA memory for all server processes. The instance attempts to keep aggregate PGA allocation near this value by tuning work areas for sorts and hashes.

Log switch interval

Time between redo log switches. A common sizing guideline keeps switches at 15 to 20 minutes during peak load; more frequent switches increase checkpoint and archiving overhead.

Online redo log group

Set of identical redo log members that Oracle writes in parallel. A group becomes active, current, or inactive; at least two groups are required for normal operation.

Control file

Binary file recording database structure, datafile and redo log locations, checkpoint information, and the RMAN repository. Multiplexed copies protect against a single media failure.

SPFILE

Server parameter file stored on the server and read at startup. Changes made with ALTER SYSTEM SCOPE=SPFILE persist across restarts, unlike changes to a traditional PFILE.

PFILE

Text initialization parameter file that can be edited manually. It is read at startup and can be used to create an SPFILE with CREATE SPFILE FROM PFILE.

Data dictionary

Set of read-only and dynamic views, owned mainly by SYS, describing database objects, users, privileges, and storage. Static views such as DBA_TABLES reflect committed metadata.

Dynamic performance views

Views whose names begin with V$ that report current instance activity and memory structures from the SGA. They are accessible when the instance is started, even before the database is open.

Locally managed tablespace

Tablespace that tracks extent allocation in a bitmap stored in its own datafile headers rather than in the data dictionary. Avoids recursive space management and reduces contention.

Dictionary-managed tablespace

Legacy tablespace type that records extent allocation in the data dictionary using UET$ and FET$ tables. Oracle recommends locally managed tablespaces for all new deployments.

Bigfile tablespace

Tablespace containing exactly one datafile that can be very large, with 4K block addressing allowing up to 32 TB per datafile. Simplifies management of very large databases.

Automatic segment space management

Tablespace attribute using bitmaps in segment headers to manage free space in blocks, replacing freelists. Set with SEGMENT SPACE MANAGEMENT AUTO and recommended for all new segments.

ASSM freelists

Automatic Segment Space Management replaces freelist-based free block tracking with bitmaps, reducing contention on segments with many concurrent inserts and simplifying free space tuning.

RMAN level 0 backup

Incremental backup that includes all blocks in the specified files, serving as the base for later level-1 incremental backups. Required before any level-1 incremental can be applied.

RMAN level 1 backup

Incremental backup containing only blocks changed since the last level-0 or level-1 backup. Cumulative level 1 backs up changes since the last level 0; differential backs up since the last incremental.

Fast Recovery Area

Disk location configured by DB_RECOVERY_FILE_DEST and DB_RECOVERY_FILE_DEST_SIZE that holds archived redo logs, RMAN backups, and control file autobackups. Space is managed automatically.

Flashback Database

Feature that rewinds the database to a prior point in time using flashback logs stored in the Fast Recovery Area. Requires ARCHIVELOG mode and DB_FLASHBACK_RETENTION_TARGET configuration.

CDB root

Container named CDB$ROOT that holds common users, common objects, and the data dictionary metadata for all pluggable databases. It must be open for a PDB to be opened.

PDB$SEED

Read-only template pluggable database used by CREATE PLUGGABLE DATABASE to create new PDBs. It cannot be modified or opened read-write, and it must remain in the CDB.

Common user

User created in the CDB root whose name must begin with a common prefix such as C##. The same user identity and password exist in every container of the CDB.

Local user

User created inside a single pluggable database with no corresponding account in the root or other PDBs. Local users cannot be created in the CDB root.

Unified auditing

Auditing architecture that writes all audit records to the AUDSYS schema, queryable through the UNIFIED_AUDIT_TRAIL view. Audit policies are created with CREATE AUDIT POLICY and enabled per object or privilege.