Free Oracle 1Z0-083 practice questions

10 free Oracle 1Z0-083 practice questions with the correct answer and a full explanation for each, taken from the CertStash pack of 181 questions. Work through them, then open each answer to check your reasoning.

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Question 1

Which three are true about thresholds, metrics, and server-generated alerts? (Choose three.)

  1. All metrics are instance related.
  2. Cleared stateful alerts are displayed by querying DBA_ALERT_HISTORY.
  3. A space usage management alert is automatically cleared after the underlying problem is resolved.
  4. They are generated by SMON when a tablespace is 97% full.
  5. Metrics are statistical counts for a specific unit.
  6. STATISTICS_LEVEL must be set to ALL to generate alerts.
Show answer and explanation

Correct answer: B, C, E

B. Cleared stateful alerts are displayed by querying DBA_ALERT_HISTORY. C. A space usage management alert is automatically cleared after the underlying problem is resolved. E. Metrics are statistical counts for a specific unit. Cleared stateful alerts are displayed by querying DBA_ALERT_HISTORY, which stores the history of all alerts including those that have been cleared. A space usage management alert is automatically cleared after the underlying problem is resolved, as the system detects when the threshold condition no longer exists. Metrics are statistical counts for a specific unit of measurement, such as transactions per second or bytes per read. Option A is incorrect because not all metrics are instance-related; some are databas-evel. Option D is incorrect because alerts are generated by the monitoring infrastructure, not specifically by SMON. Option F is incorrect because STATISTICS_LEVEL can be set to TYPICAL (the default) and still generate alerts; ALL is not required.

Why the other options are wrong

  • A. Some metrics are database-level, not all are instance-related.
  • D. Alerts are generated by the monitoring system in response to threshold violations, not by SMON specifically.
  • F. Alerts are generated with STATISTICS_LEVEL set to TYPICAL; ALL is not required.

Question 2

While backing up to an SBT channel, you determine that the read phase of your compressed Recovery Manager (RMAN) incremental level 0 backup is a bottleneck.

FORCE LOGGING is enabled for the database.

Which two could improve read performance? (Choose two.)

  1. Increase the size of tape I/O buffers.
  2. Disable FORCE LOGGING for the database.
  3. Increase the size of the database buffer cache.
  4. Enable asynchronous disk I/O.
  5. Increase the level of RMAN multiplexing.
Show answer and explanation

Correct answer: D, E

D. Enable asynchronous disk I/O. E. Increase the level of RMAN multiplexing. Enabling asynchronous disk I/O allows the database to issue multiple I/O requests without waiting for each to complete, significantly improving read throughput during the backup read phase. Increasing the level of RMAN multiplexing allows multiple data streams to be read and processed concurrently, which directly improves performance when reading from disk. Option A is incorrect because tape I/O buffers affect write performance to tape, not the read phase from disk. Option B is incorrect because FORCE LOGGING does not impact backup read performance; it ensures all changes are logged but does not affect data block access speed. Option C is incorrect because the database buffer cache does not significantly impact the initial read of blocks during backup, as backup typically bypasses the buffer cache.

Why the other options are wrong

  • A. Tape I/O buffers affect the write phase to tape, not the read phase from disk.
  • B. FORCE LOGGING ensures redo logging but does not improve read performance during backup.
  • C. The database buffer cache has minimal impact on backup read performance as backup typically bypasses it.

Question 3

For which two requirements can you use the USER_TABLESPACE clause with the CREATE PLUGGABLE DATABASE command? (Choose two.)

  1. to specify a default tablespace in a PDB cloned from another PDB in the same CDB.
  2. to exclude all tablespaces except SYSTEM, SYSAUX, and TEMP when plugging in a PDB
  3. to include specific user tablespaces only when relocating a PDB
  4. to specify the list of user tablespaces to include when moving a non-CDB to a PDB
  5. to exclude a temp tablespace when plugging in a PDB
  6. to specify the list of tablespaces to include when creating a PDB from the CDB seed
Show answer and explanation

Correct answer: B, D

B. to exclude all tablespaces except SYSTEM, SYSAUX, and TEMP when plugging in a PDB D. to specify the list of user tablespaces to include when moving a non-CDB to a PDB The USER_TABLESPACES clause of CREATE PLUGGABLE DATABASE controls which user tablespaces the new PDB keeps from the source. Specifying NONE when plugging in a PDB leaves only SYSTEM, SYSAUX, and the temp tablespace in the new PDB, and you can supply an explicit list of user tablespaces when adopting a non-CDB as a PDB. The clause is supported for clone, plug-in, and non-CDB adoption operations, and tablespaces left out are created offline and unusable.

Why the other options are wrong

  • A. A default tablespace for a PDB is assigned with the DEFAULT TABLESPACE clause or ALTER PLUGGABLE DATABASE, not with USER_TABLESPACES.
  • C. A relocate operation moves the PDB in its entirety, so this clause does not filter tablespaces during relocation.
  • E. The temp tablespace is always carried into the new PDB and cannot be excluded by this clause.
  • F. The CDB seed contains no user tablespaces, so there is nothing for the clause to include or exclude when creating a PDB from the seed.

Question 4

Which three are true about requirements for various FLASHBACK operations? (Choose three.)

  1. FLASHBACK transaction query requires undo to retrieve all versions of a row that existed between two points in time.
  2. FLASHBACK drop requires that the RECYCLEBIN parameter be set to ON.
  3. FLASHBACK version query requires that the RECYCLEBIN parameter be set to ON.
  4. FLASHBACK DATA ARCHIVE requires undo to store all versions of all rows of a table being tracked.
  5. FLASHBACK drop requires undo to retrieve all versions of a row that existed between two points in time.
  6. FLASHBACK version query requires undo to retrieve all versions of a row that existed between two points in time.
Show answer and explanation

Correct answer: B, D, F

B. FLASHBACK drop requires that the RECYCLEBIN parameter be set to ON. D. FLASHBACK DATA ARCHIVE requires undo to store all versions of all rows of a table being tracked. F. FLASHBACK version query requires undo to retrieve all versions of a row that existed between two points in time. Flashback Drop relies on the recycle bin, so RECYCLEBIN must be set to ON for dropped objects to be recoverable. Flashback Version Query reads undo to reconstruct every committed version of a row between two points in time. Flashback Data Archive also depends on undo: the FBDA process reads the undo generated by transactions on a tracked table to capture every row version before writing the history to the archive tables.

Why the other options are wrong

  • A. Flashback Transaction Query reads undo to report the transactions and the SQL needed to undo them, not the set of row versions between two points in time.
  • C. Flashback Version Query works from undo data and is unaffected by the RECYCLEBIN setting.
  • E. Flashback Drop recovers objects from the recycle bin, not from undo.

Question 5

Which three actions are performed by the Oracle Preinstallation RPM, oracle-databas-erver-xxxx-preinstall, for Oracle Grid Infrastructure, where xxxx is the Oracle version and release? (Choose three.)

  1. performing checks to ensure minimum configuration requirements for Oracle Grid Infrastructure are met
  2. creating the oracle OS user
  3. creating the OSDBA (dba) group
  4. creating the oraInventory (oinstall) group
  5. creating the grid OS user
  6. configuring the OS for Oracle Automatic Storage Management shared storage access
Show answer and explanation

Correct answer: B, C, D

B. creating the oracle OS user C. creating the OSDBA (dba) group D. creating the oraInventory (oinstall) group The oracle-database-server preinstall RPM creates the oracle OS user required for Oracle Grid Infrastructure installation. It creates the OSDBA (dba) group that provides database administration privileges. It creates the oraInventory (oinstall) group that manages the Oracle inventory directory. Option A is incorrect because the RPM performs automatic configuration but does not run explicit checks for minimum requirements; validation occurs during actual Grid Infrastructure installation. Option E is incorrect because the RPM does not create the grid OS user; that user may already exist or is created separately. Option F is incorrect because the RPM configures the OS for Oracle database, not specifically for ASM shared storage access.

Why the other options are wrong

  • A. The RPM does not perform explicit minimum configuration checks; that occurs during Grid Infrastructure setup.
  • E. The RPM does not create the grid OS user.
  • F. The RPM configures for Oracle Database, not specifically for ASM shared storage.

Question 6

Which two are true about common objects? (Choose two.)

  1. They can be created only in CDB$ROOT.
  2. They can be only metadata-linked in an application container.
  3. They can exist in user-defined schemas only in application containers.
  4. They can exist in CDB$ROOT and an application root.
  5. They can be extended data-linked in CDB$ROOT.
  6. They can be created only in an application root.
Show answer and explanation

Correct answer: C, D

C. They can exist in user-defined schemas only in application containers. D. They can exist in CDB$ROOT and an application root. A common object is defined in CDB$ROOT or in an application root and is visible in the containers below it. In CDB$ROOT the common objects are the Oracle-supplied objects in Oracle-maintained schemas, while application common objects are user-created and can live in user-created schemas in an application root. That makes both the location statement and the user-defined schema statement true.

Why the other options are wrong

  • A. Common objects are also created in an application root as application common objects.
  • B. Inside an application container a common object can be metadata-linked, data-linked, or extended data-linked, so metadata linking is not the only option.
  • E. Extended data-linked objects exist only in application containers, never in CDB$ROOT.
  • F. CDB$ROOT holds the Oracle-supplied common objects, so creation is not restricted to an application root.

Question 7

Which two are true about the Automatic Database Diagnostic Monitor (ADDM)? (Choose two.)

  1. It analyzes a period of time corresponding to the 12 hours of activity.
  2. It runs automatically after each AWR snapshot.
  3. A DBA can run it manually.
  4. Results are written to the alert log.
  5. It analyzes a period of time corresponding to the last day of activity.
Show answer and explanation

Correct answer: B, C

B. It runs automatically after each AWR snapshot. C. A DBA can run it manually. ADDM runs automatically after each AWR snapshot is taken, analyzing the performance data collected during that snapshot interval. A DBA can manually invoke ADDM at any time to perform analysis on a specific time period. Option A is incorrect because ADDM analyzes the time period covered by each AWR snapshot interval, typically one hour, not 12 hours. Option D is incorrect because ADDM results are written to the ADDM repository and accessed via views and reports, not directly to the alert log. Option E is incorrect because ADDM does not analyze the entire last day; it analyzes specific snapshot intervals as defined by AWR.

Why the other options are wrong

  • A. ADDM analyzes the interval of each AWR snapshot, typically one hour, not 12 hours.
  • D. ADDM results are stored in the ADDM repository, not written to the alert log.
  • E. ADDM analyzes specific AWR snapshot intervals, not the entire last day.

Question 8

Which two are true about server-generated alerts? (Choose two.)

  1. Stateful alerts must be created by a DBA after resolving the problem.
  2. Stateless alerts can be purged manually from the alert history.
  3. Stateless alerts can be cleared manually.
  4. Stateless alerts are automatically cleared.
  5. Stateful alerts are purged automatically from the alert history.
Show answer and explanation

Correct answer: B, C

B. Stateless alerts can be purged manually from the alert history. C. Stateless alerts can be cleared manually. Stateless alerts, such as snapshot too old or resumable session suspended, are written straight to the alert history because there is no threshold condition to return to normal. Since the database never clears them on its own, an administrator clears them manually and can also purge them manually from the alert history. Stateful alerts behave differently: they appear in DBA_OUTSTANDING_ALERTS and are cleared automatically once the threshold condition is no longer met.

Why the other options are wrong

  • A. Stateful alerts are raised automatically by the database when a threshold is crossed and cleared automatically when the condition is resolved, so a DBA does not create them.
  • D. Automatic clearing applies to stateful alerts; a stateless alert stays until it is cleared by an administrator.
  • E. A cleared stateful alert moves into the alert history and stays there until it is purged; it is not removed automatically.

Question 9

Which three are located by using environment variables? (Choose three.)

  1. the Optimal Flexible Architecture (OFA) compliant path to store Oracle software and configuration files.
  2. the location of Oracle Net Services configuration files
  3. the list of a disk group names to be mounted by an Oracle Automatic Storage Management (ASM) instance at startup
  4. default directories for temporary files used by temporary tablespaces
  5. the temporary disk space used by Oracle Installer during installation
  6. the maximum number of database files that can be opened by a database instance
Show answer and explanation

Correct answer: A, B, E

A. the Optimal Flexible Architecture (OFA) compliant path to store Oracle software and configuration files. B. the location of Oracle Net Services configuration files E. the temporary disk space used by Oracle Installer during installation Environment variables in Oracle specify key directory locations and configuration paths. ORACLE_BASE defines the OFA-compliant root path for Oracle software and configuration files (A). TNS_ADMIN points to the location of Oracle Net Services configuration files like sqlnet.ora and tnsnames.ora (B). TEMP or TMPDIR specify the temporary disk space used by Oracle Installer during installation (E). Disk group names are specified in ASM configuration files or parameter files, not environment variables (C). Default directories for temporary tablespaces are configured in the database parameter file, not through environment variables (D). The maximum number of database files is a static parameter in the database initialization file, not located via environment variables (F).

Why the other options are wrong

  • C. Disk group names are specified in ASM parameter files or configuration, not environment variables.
  • D. Temporary tablespace directories are configured in database parameter files, not environment variables.
  • F. Maximum open files is a static database parameter, not located via environment variables.

Question 10

Which three are true about opatchauto? (Choose three.)

  1. It performs a shutdown and then a restart of all processes in both Oracle Grid Infrastructure and Oracle Database home during the patching process.
  2. It must be invoked by a user with root user privileges.
  3. Patches are applied via opatchauto.
  4. Users must always input patch plans to opatchauto.
  5. It requires the Oracle Grid Infrastructure and Oracle Database instances to be shut down before being invoked.
  6. It applies patches in nonrolling mode by default.
  7. It is used to apply interim patches to Oracle Grid Infrastructure and Oracle Database home combinations.
Show answer and explanation

Correct answer: A, B, G

A. It performs a shutdown and then a restart of all processes in both Oracle Grid Infrastructure and Oracle Database home during the patching process. B. It must be invoked by a user with root user privileges. G. It is used to apply interim patches to Oracle Grid Infrastructure and Oracle Database home combinations. opatchauto is the automation front end of OPatch used to apply interim patches to combined Oracle Grid Infrastructure and Oracle Database home configurations. It must be run by root because it manipulates the Grid Infrastructure stack and root-owned files. It also handles the outage itself, stopping the Grid Infrastructure and database processes on the node and restarting them once the patching completes.

Why the other options are wrong

  • C. This is too broad: patches for single-instance and non-clustered Oracle homes are applied with opatch apply rather than through opatchauto.
  • D. Patch plans are not required input; opatchauto determines and drives the patching steps itself.
  • E. The stack must be up when opatchauto is invoked so that the tool can stop and later restart the services in the correct order.

That was 10 of 181.

The full Oracle 1Z0-083 pack has all 181 questions, each with the answer, the explanation and why the other options are wrong, plus a questions-only copy for timed runs. US$39, paid once, with free monthly updates and a pass-or-your-money-back guarantee.

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