Essbase Data Integrity

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

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

Transactions Database updates Data load Calculation Lock and Send

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

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

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

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

Locks and Committed Access

Locks and Uncommitted Access

Guidelines for Choosing an Isolation Level

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

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

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

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

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