Oracle Database Administration from Zero to Hero - Managing Undo Data (Part 2 of 3)

The video tutorial explains the importance of undo tablespace in databases, focusing on how to determine the appropriate size and retention settings. It covers the use of undo statistics to estimate retention and space requirements, and introduces the Undo Advisor for evaluating tablespace size. The tutorial also provides a formula for calculating the required undo size and discusses the role of AWR snapshots in this process.

What is the primary purpose of ensuring the undo tablespace size is large enough?

• To maintain required retention

• To enhance security

• To reduce storage costs

• To increase database speed

Which column helps in estimating the undo retention to be set at the database level?

• UNDPLKS

• Max QUERY Len

• Max QUERY ID

• UNXPLKRELCNT

What does the column 's s OLD ERRCNT' indicate?

• Total undo blocks consumed

• Number of times error Ora 01555 occurred

• SQL identifier of the longest query

• Number of unexpired blocks removed

What is the formula to estimate the required undo size for a given retention?

• Undo size = retention + block size

• Undo size = retention x block size

• Undo size = retention x undo block per second x standard block size

• Undo size = retention / block size

Why should you avoid decreasing the undo size even if it seems larger than required?

• To prevent data loss

• To avoid potential long queries in the future

• To save on storage costs

• To improve query speed

What is the role of the Undo Advisor in Oracle Database?

• To create new tables

• To evaluate the undo tablespace size

• To delete unnecessary data

• To enhance security protocols

What do AWR snapshots provide for the Undo Advisor?

• A history of database errors

• Estimation data for undo tablespace evaluation

• A list of all database users

• A log of all executed queries

What is the first step in creating an undo advisor task?

• Set the retention period

• Review the findings

• Create a task using DBMS advisor

• Execute the task

What information is required to create an undo advisor task?

• Database name and user ID

• Error log details

• Start and end AWR snapshot IDs

• SQL query code

How can you monitor the progress of an undo advisor task?

• By checking the database logs

• By querying the view DBA ADVISOR Tasks

• By observing the database performance

• By reviewing the error messages