Monday, September 9, 2013

Tips and important concepts in Informatica?

1. You cannot have Truncate Target table and Incremental Aggregation enabled together in a session.
2. For Bulk load, you cannot have CHECK constraints in the database. And Primary Key,Foreign keys should not be defined in the database but can be defined in the Designer.
3. The DTM initializes a Master Thread which again invokes 5 threads:
1)Pre-Session Thread
2)Post-Session Thread
3)Reader Thread
4)Writer Thread
5)Transformation Thread
4. You can improve performance by adding the Partitions to the mapping which will give us the provision of maximum cpu usage.
5. Database Partitioning, Hash Auto Key, Hash user key, Simple Pass through ,Round Robin, Key Range are the type of Partitions available.
6. Limitation of maximum number of Session Logs: The session logs can be limited if you choose to save by runs You can specify up to 2,147,483,647 historical logs. And will be unlimited if you choose to save by timestamp.
7. Sequence Limitations: You can associate a Sequence ID with a lookup port configured with the Bigint, Integer, or Small Integer datatype. The bigint maximum value is 9,223,372,036,854,775,807 and the integer or small integer maximum value is 2,147,483,647 
8. Push down Optimization is of three types Source –based,target based, full.
9. Push Down Optimization means to push the Transformation logic towards source, or Target or throughout the mapping which means Integration service will create SQL queries based on the type of PDO selected and the mapping logic available.
10. To increase session performance, push transformation logic to the source or target database. Based on the mapping and session configuration, the Integration Service executes SQL against the source or target database instead of processing the transformation logic within the Integration Service.
11. There are built in Parameters and User-defined Parameters available.
12. $$$SESSSTARTTIME can be used in the Sessions, mappings, source qualifiers, expressions and Filters where as SESSSTARTTIME can be used only in expressions.

13. Better to use SESSSTARTTIME if you don’t want time part when compared to sysdate.

1 comment:

  1. Hello Mr. Gowtham,

    Can u plz discuss more about PUSHDOWN Optimization Techniques.

    Thank you

    ReplyDelete