Table of Contents

Search

  1. Preface
  2. Introduction to Transformations
  3. Transformation Ports
  4. Transformation Caches
  5. Address Validator Transformation
  6. Aggregator Transformation
  7. Association Transformation
  8. Bad Record Exception Transformation
  9. Case Converter Transformation
  10. Classifier Transformation
  11. Comparison Transformation
  12. Consolidation Transformation
  13. Data Masking Transformation
  14. Data Processor Transformation
  15. Decision Transformation
  16. Duplicate Record Exception Transformation
  17. Expression Transformation
  18. Filter Transformation
  19. Hierarchical to Relational Transformation
  20. Java Transformation
  21. Java Transformation API Reference
  22. Java Expressions
  23. Joiner Transformation
  24. Key Generator Transformation
  25. Labeler Transformation
  26. Lookup Transformation
  27. Lookup Caches
  28. Dynamic Lookup Cache
  29. Match Transformation
  30. Match Transformations in Field Analysis
  31. Match Transformations in Identity Analysis
  32. Normalizer Transformation
  33. Merge Transformation
  34. Parser Transformation
  35. Python Transformation
  36. Rank Transformation
  37. Read Transformation
  38. Relational to Hierarchical Transformation
  39. REST Web Service Consumer Transformation
  40. Router Transformation
  41. Sequence Generator Transformation
  42. Sorter Transformation
  43. SQL Transformation
  44. Standardizer Transformation
  45. Union Transformation
  46. Update Strategy Transformation
  47. Web Service Consumer Transformation
  48. Parsing Web Service SOAP Messages
  49. Generating Web Service SOAP Messages
  50. Weighted Average Transformation
  51. Window Transformation
  52. Write Transformation
  53. Appendix A: Transformation Delimiters

Developer Transformation Guide

Developer Transformation Guide

Update Strategy Transformation on the Blaze Engine

Update Strategy Transformation on the Blaze Engine

Some processing rules for the Blaze engine differ from the processing rules for the Data Integration Service.

General Restrictions

You can use the Update Strategy transformation on the Hadoop distributions that support Hive ACID.
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

0 COMMENTS

We’d like to hear from you!