Oracle 1Z0-084 Exam Dumps

The optimizer_adaptive_statistics parameter, when set to TRUE, enables the optimizer to use adaptive statistics, such as SQL Plan Directives, to help improve plans by automatically adjusting them based on the actual execution statistics.

Oracle Database SQL Tuning Guide, 19c

The Automatic Database Diagnostic Monitor (ADDM) analyzes and reports on various types of performance problems. For Pluggable Databases (PDBs), it can identify issues such as I/O capacity limits which may hinder the overall performance by causing bottlenecks. Additionally, ADDM can report on user I/O waits, which can indicate performance issues related to the time it takes for user queries to read data from the disk.

Oracle Multitenant Administrator's Guide, 19c

Oracle Database Performance Tuning Guide, 19c

When both a SQL Profile and a SQL Plan Baseline are in place, the SQL Profile has a stronger preference and the optimizer is more likely to choose the execution plan from the SQL Profile.

C) A SQL Profile is generally more influential than a SQL Plan Baseline because it contains additional statistics and directives that help the optimizer to generate a more efficient execution plan. If both exist, the optimizer will use the profile's plan unless the baseline's plan is proven to be better through the SQL performance monitoring process.

E) SQL Plan Baselines must be accepted before they can be used by the optimizer. If a SQL Plan Baseline is not accepted, it will not be considered for generating the execution plan. Therefore, the presence of an unaccepted SQL Plan Baseline will not automatically force the optimizer to use its plan.

Oracle Database SQL Tuning Guide, 19c

Oracle Database Administrator's Guide, 19c

When you execute DBMS_AUTO_TASK_ADMIN.DISABLE, it disables all automated maintenance tasks related to the Auto Task framework. This includes tasks such as the Automatic SQL Tuning Advisor, Automatic Segment Advisor, and others. However, the Automatic Optimizer Statistics Collection (D) remains enabled as it is not part of the Auto Task framework. The gathering of optimizer statistics is controlled separately and is a critical part of the database's self-tuning mechanism to ensure the optimizer has up-to-date information about the data distribution within tables and indexes.

Reference

Oracle Database 19c PL/SQL Packages and Types Reference - DBMS_AUTO_TASK_ADMIN

Oracle Database 19c Database Administrator's Guide - Managing Optimizer Statistics

When importing objects that used the In-Memory (IM) column store in their source database using Oracle Data Pump, the following statements are true:

D (Correct): The TRANSFORM clause can be used to alter object creation DDL during import operations. This can include adding the INMEMORY clause to tables that were not originally using the IM column store.

F (Correct): The import operation can preserve the INMEMORY attributes of tables as they were at the time of export, effectively replicating the IM column store settings from the source database.

The other statements are not accurate in the context of Data Pump import:

A (Incorrect): Data Pump does not give preference to the IM column store clauses at the tablespace level over table-level definitions unless explicitly specified by the TRANSFORM clause.

B (Incorrect): While Data Pump can transport existing INMEMORY attributes, it is not mandatory. It is controlled by the INCLUDE or EXCLUDE Data Pump parameters or the TRANSFORM clause.

C (Incorrect): The INMEMORY_CLAUSE parameter is not part of the Data Pump Export utility. To modify the IM column store clauses, you would use the TRANSFORM parameter during import, not export.

E (Incorrect): Data Pump does not ignore the IM column store clause unless specifically instructed to do so via the EXCLUDE parameter.

Oracle Database Utilities: Data Pump Export

Oracle Database Utilities: Data Pump Import