Automatic Block Media Recovery can be a significant feature for maintaining data integrity within a Data Guard configuration.
A corrupt block on the primary database can be automatically recovered, using a block from a standby database with Real-Time Query enabled (A): When a corrupted block is encountered on the primary database, Oracle can automatically replace it with a good block from the standby database where Real-Time Query is enabled, leveraging the standby as a source of good data.
A corrupt block on the primary database is automatically recovered, using a block from a flashback log from the primary database (E): If a good block version is available in the flashback logs of the primary database, Automatic Block Media Recovery can use it to recover the corrupted block on the primary.
Reference:
Oracle Database Backup and Recovery User's Guide

In a Data Guard configuration where the protection mode is set to Maximum Availability and synchronous redo transport is enabled, if the standby destination fails to acknowledge the reception of redo within the net_timeout period, the primary database will terminate the synchronous redo transport mode connections to the standby database to protect the primary database from hanging (C). The primary database then operates in a Maximum Performance mode until the issue is resolved. This behavior ensures that the primary database can continue to process transactions even when the standby database is temporarily unavailable.
References:The Oracle Data Guard Broker documentation and Oracle Data Guard Concepts and Administration guide detail the behavior of different protection modes and the response to network timeouts, including the fallback to asynchronous redo transport to maintain primary database availability.

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.

The error indicates that switching the protection mode to Maximum Protection is not possible due to the presence of a snapshot standby database in the Data Guard configuration, which cannot participate in synchronous redo transport required by the Maximum Protection mode. Therefore, the correct answer is:
* D. Cats is a snapshot standby database.
Comprehensive Detailed Explanation:In an Oracle Data Guard environment, the Maximum Protection mode requires that all redo data be transmitted synchronously to at least one standby database, ensuring no data loss even in the event of a primary database failure. However, a snapshot standby database, by its nature, allows read-write access and is temporarily disconnected from the redo stream, which makes it unable to participate in the synchronous redo transport required by Maximum Protection mode. The presence of a snapshot standby database in the Data Guard configuration thus prevents the activation of Maximum Protection mode, as it cannot guarantee zero data loss without a standby database capable of receiving redo data synchronously.
References:Oracle Data Guard documentation clearly outlines the requirements and restrictions of different protection modes, including the necessity for standby databases to participate in synchronous redo transport to enable Maximum Protection mode. The inability of snapshot standby databases to fulfill this requirement is a key consideration when planning Data Guard configurations and protection levels.

The SQL apply lag on a logical standby database can be caused by several factors:
A: An undersized undo tablespace can lead to delays in SQL apply operations as it may not be able to handle the volume of undo records generated by the SQL apply process.
B: SQL apply operations that do full table scans can consume significant system resources, potentially leading to higher apply lag.
C: An increased number of bulk updates on the primary database may generate a large volume of redo data, which can cause apply lag if the logical standby cannot apply the changes quickly enough.
F: An undersized shared pool may affect the parsing and execution of SQL statements by SQL apply, which can contribute to the apply lag.
Option D is less likely to be a direct cause of SQL apply lag compared to bulk updates, as inserts generate new data rather than modifying existing data, which SQL apply can typically handle more efficiently.
Option E is incorrect because the size of the standby redo log files on the primary database impacts redo transport lag, not SQL apply lag.