A logical standby database is part of Oracle Data Guard and allows the standby database to be open for read-write operations, providing additional flexibility. The requirements met by a logical standby database include: Support for workloads requiring additional materialized views (A): Logical standby databases can support materialized views, allowing for complex data summarization and reporting workloads. It can be used to create additional tables (C): Unlike physical standby databases, logical standby databases allow for the creation of additional tables that do not exist in the primary database, enabling custom workloads and reporting. It can be used for Real Application Testing without affecting the disaster recovery capabilities (E): Logical standby databases can be used to test application changes, patches, and upgrades while still maintaining their role as part of the disaster recovery strategy. Support for workloads requiring additional indexes (F): Logical standby databases allow for the creation of additional indexes to optimize query performance for reporting and analytical workloads. Reference: Oracle Data Guard Concepts and Administration Oracle Database High Availability Overview

A fast recovery area must be configured (B): Flashback Database requires a fast recovery area to be

set up because flashback logs are stored there. The fast recovery area is a unified storage location for

all recovery-related files and activities.

The database must be in ARCHIVELOG mode (C): Flashback Database operation relies on the ability

to archive redo logs. Therefore, the database must be running in ARCHIVELOG mode for Flashback

Database to be enabled.

Reference:

Oracle Database Backup and Recovery User's Guide

Oracle Data Guard Concepts and Administration Guide

Logical standby databases are a key feature of Oracle Data Guard and offer several distinct

advantages, especially in terms of flexibility for reporting, upgrades, and disaster recovery:

Disaster-recovery solution with switchover and failover options (A): Logical standby databases

provide a robust disaster-recovery solution, ensuring that any data updated on the primary database

can be recovered. They support both switchover and failover operations, allowing for smooth role

transitions between the primary and standby databases.

Used for reporting workloads requiring additional indexes or materialized views (B): Logical standby

databases can be opened for read-write operations and can have additional indexes or materialized

views that are not present in the primary database. This makes them ideal for offloading reporting

and querying workloads from the primary database.

Database rolling release upgrades (D): Logical standby databases can be used to perform rolling

upgrades of the Oracle Database software. This allows the database to be upgraded with minimal

downtime, as the standby database is upgraded first, followed by a switchover to make it the new

primary.

Reference:

Oracle Data Guard Concepts and Administration Guide

Oracle Database High Availability Overview

Logical standby databases allow the execution of DDL and DML operations, which makes them

suitable for maintaining bitmap indexes and materialized views without affecting the performance of

the primary database .

Logical standby databases can be used for performing rolling upgrades and patching with minimum

downtime, meeting another requirement .

They also enable the testing of new application software releases against an up-to-date replica of the

primary database, fulfilling the last requirement.

Other configurations involving physical standby databases or combinations of logical and physical

standby databases might not meet all the specified requirements as efficiently or with the same level

of performance isolation for the primary database.

When STANDBY_FILE_MANAGEMENT is set to AUTO, the Oracle Data Guard automatically creates,

deletes, and renames files on the standby database to match the changes made on the primary

database. The tasks that lead to the automatic creation of files on the standby include:

Adding a data file or creating a tablespace (C): When a new tablespace is created or a new data file is

added on the primary database, the standby database automatically replicates this action,

maintaining structural consistency with the primary database.

Creating a PDB from the existing PDB within the same CDB (D): Creating a new Pluggable Database

(PDB) within a Multitenant Container Database (CDB) on the primary database triggers an automatic

creation of the corresponding PDB within the standby CDB.

Reference:

Oracle Data Guard Concepts and Administration Guide

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A Physical Standby Database can indeed be converted into a Logical Standby Database, providing

flexibility in a Data Guard configuration. This allows for the database to switch roles and supports SQL

apply operations, enabling more granular control over the data and transactions being replicated and

applied. Additionally, having a configuration with a primary database and one or more physical

standby databases allows for rolling upgrades to be performed. This means that each database in the

Data Guard configuration can be upgraded in a phased manner, minimizing downtime and ensuring

high availability during the upgrade process​​​​.

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The EDIT DATABASE...SET PARAMETER command in Data Guard Management (DGMGRL) is used to

modify the value of initialization parameters for a database within a Data Guard configuration. This

command can be used to modify both static and dynamic parameters, but if a static parameter is

changed, the new value will take effect only after the database is restarted. The database must be up

and running for the command to execute, and the values set using the command are directly applied

to the specified database (in this case, 'boston') .

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