1. Essbase Data Integrity

2. Objectives After completing this lesson, you should be able to:
Understand the mechanisms through which Essbase maintains data integrity
Explain transactions in Essbase
Describe locks in Essbase
Explain isolation levels in Essbase
Understand the guidelines for choosing an isolation level in Essbase

3. Essbase Data Integrity
Essbase mechanisms for maintaining block storage integrity:
Transactions
Locks
Isolation levels

4. Transactions
Database updates
Data load
Calculation
Lock and Send

5. Locks Tracked in dbname.tct Write locks (exclusive) to:
Retrieve and lock
Calculate derived blocks
Load data
Restructure
Read locks (shared) to:
Retrieve reports
Prohibit modifications to data blocks

6. Isolation Levels Data is committed automatically by Essbase kernel.
Two isolation levels are available for block storage databases:
Committed access
Uncommitted access (default)

7. Committed Access
Holds locks on all data blocks involved in a transaction until the transaction is completed
Saves blocks temporarily to disk until the transaction is finished
Rolls back the transaction completely in the event of a failure
Provides a high level of data consistency

8. Uncommitted Access Is the default isolation level
Provides short-term write locks (block-by-block)
Requires a user-defined synchronization point that:
Breaks large transactions into multiple smaller transactions
Determines the size of transactions
Number of blocks
Number of rows

9. Locks and Committed Access

10. Locks and Uncommitted Access

11. Guidelines for Choosing an Isolation Level

12. Quiz Select the Essbase mechanisms for maintaining data integrity
in block storage databases.
License agreements
Transactions
Locks
Isolation levels
Answers: 2, 3, 4

13. Quiz
When user A has a read lock on a range of data blocks, user B cannot make changes to the data in those blocks.
True
False
Answers: 1

14. Quiz Select the Essbase isolation levels. Committed access
Uncommitted access
Transparent access
Dynamic access
Answers: 1, 2

15. Quiz
With Uncommitted access, Essbase Server commits data as soon as a synchronization point is reached.
True
False
Answers: 1

16. Summary In this lesson, you should have learned to:
Understand the mechanisms through which Essbase maintains data integrity
Explain transactions in Essbase
Describe locks in Essbase
Explain isolation levels in Essbase
Understand the guidelines for choosing an isolation level in Essbase