Table of Contents

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  1. Preface
  2. Introduction to Informatica Big Data Management
  3. Mappings
  4. Sources
  5. Targets
  6. Transformations
  7. Data Preview
  8. Cluster Workflows
  9. Profiles
  10. Monitoring
  11. Hierarchical Data Processing
  12. Hierarchical Data Processing Configuration
  13. Hierarchical Data Processing with Schema Changes
  14. Intelligent Structure Models
  15. Stateful Computing
  16. Appendix A: Connections
  17. Appendix B: Data Type Reference
  18. Appendix C: Function Reference

Update Strategy Transformation on the Blaze Engine

Update Strategy Transformation on the Blaze Engine

You can use the Update Strategy transformation on the Hadoop distributions that support Hive ACID.
Some processing rules for the Blaze engine differ from the processing rules for the Data Integration Service.

General Restrictions

If the Update Strategy transformation receives multiple update rows for the same primary key value, the transformation selects one random row to update the target.
If multiple Update Strategy transformations write to different instances of the same target, the target data might be unpredictable.
The Blaze engine executes operations in the following order: deletes, updates, inserts. It does not process rows in the same order as the Update Strategy transformation receives them.
Hive targets always perform Update as Update operations. Hive targets do not support Update Else Insert or Update as Insert.

Mapping Validation and Compile Validation

Mapping validation fails in the following situations:
  • The Update Strategy transformation is connected to more than one target.
  • The Update Strategy transformation is not located immediately before the target.
  • The Update Strategy target is not a Hive target.
  • The Update Strategy transformation target is an external ACID table.
  • The target does not contain a primary key.
  • The Hive target property to truncate the target table at run time is enabled.
  • The Hive target property to create or replace the target table at run time is enabled.
The mapping fails in the following situation:
  • The target is not ORC bucketed.
  • The Hive target is modified to have fewer rows than the actual table.
Compile validation errors occur and the mapping execution stops in the following situations:
  • The Hive version is earlier than 0.14.
  • The target table is not enabled for transactions.

Using Hive Target Tables

To use a Hive target table with an Update Strategy transformation, you must create the Hive target table with the following clause in the Hive Data Definition Language:
TBLPROPERTIES ("transactional"="true")
.
To use an Update Strategy transformation with a Hive target, verify that the following properties are configured in the hive-site.xml configuration set associated with the Hadoop connection:
hive.support.concurrency true hive.enforce.bucketing true hive.exec.dynamic.partition.mode nonstrict hive.txn.manager org.apache.hadoop.hive.ql.lockmgr.DbTxnManager hive.compactor.initiator.on true hive.compactor.worker.threads 1


Updated July 10, 2020