Q1 : What is parallel processing in Informatica?
A : After optimizing the session to its fullest, we can further improve performance by exploiting under utilized hardware power. This refers to parallel processing and we can achieve this in Informatica PowerCenter using Partitioning Sessions.
The Informatica PowerCenter Partitioning Option increases the performance of the PowerCenter through parallel data processing. The Partitioning option will let you split the large data set into smaller subsets which can be processed in parallel to get a better session performance.
Q2 : What are the different ways to implement parallel processing in Informatica?
A : We can implement parallel processing using various types of partition algorithms:
Database partitioning: The Integration Service queries the database system for table partition information. It reads partitioned data from the corresponding nodes in the database.
Round-Robin Partitioning: Using this partitioning algorithm, the Integration service distributes data evenly among all partitions. It makes sense to use round-robin partitioning when you need to distribute rows evenly and do not need to group data among partitions.
Hash Auto-Keys Partitioning: The PowerCenter Server uses a hash function to group rows of data among partitions. When the hash auto-key partition is used, the Integration Service uses all grouped or sorted ports as a compound partition key. You can use hash auto-keys partitioning at or before Rank, Sorter, and unsorted Aggregator transformations to ensure that rows are grouped properly before they enter these transformations.
Hash User-Keys Partitioning: Here, the Integration Service uses a hash function to group rows of data among partitions based on a user-defined partition key. You can individually choose the ports that define the partition key.
Key Range Partitioning: With this type of partitioning, you can specify one or more ports to form a compound partition key for a source or target. The Integration Service then passes data to each partition depending on the ranges you specify for each port.
Pass-through Partitioning: In this type of partitioning, the Integration Service passes all rows from one partition point to the next partition point without redistributing them.
Q3 : What is INFORMATICA? Why do we need it?
A : INFORMATICA is a software development firm which offers some data integration solution for ETL, data virtualization, master data management, data quality, data replica, ultra messaging etc.
Some of the popular INFORMATICA products are:
- INFORMATICA PowerCenter
- INFORMATICA PowerConnect
- INFORMATICA Power Mart
- INFORMATICA Power Exchange
- INFORMATICA Power Analysis
- INFORMATICA Power Quality
We need INFORMATICA while working with data systems which contain data to perform certain operations along with a set of rules. INFORMATICA facilitates operations line cleaning and modifying data from structured and unstructured data systems.
Q4 : What is Source Qualifier Transformation in INFORMATICA?
A : Source Qualifier Transformation is useful in Mapping, whenever we add relational flat files it is automatically created. It is an active and connected transformation that represents those rows which are read by integration service.
Q5 : What is INFORMATICA PowerCenter?
A : INFORMATICA PowerCenter is an ETL/Data Integration Tool which is used to connect and retrieve data from different sources and data processing. PowerCenter processes a high volume of data and supports data retrieval from ERP sources such as SAP, PeopleSoft etc.
You can connect PowerCenter to database management systems like SQL and Oracle to integrate data into the third system.
Q6 : How many repositories can be created in Informatica?
A : There can be any number of repositories in Informatica but eventually it depends on number of ports.
Q7 : What are the different Clients of PowerCenter?
A : Here is the list of PowerCenter clients:
- PowerCenter designer
- PowerCenter workflow monitor
- PowerCenter workflow manager
- PowerCenter repository manager
Q8 : What are the different Components of PowerCenter?
A : Given below are the 7 important components of PowerCenter:
- PowerCenter Service
- PowerCenter Clients
- PowerCenter Repository
- PowerCenter Domain
- Repository Service
- Integration Service
- PowerCenter Administration Console
- Web Service Hub
Q9 : What are Sessions?
A : Session is a Set of Instructions that are used while moving data from the source to destination. We can partition the session to implement several sequences of sessions to improve the server performance.
After creating session we can use server manager or command line program pmcmd to stop or start the session.
Q10 : Which are the different editions of INFORMATICA PowerCenter that are available?
A : Different editions of INFORMATICA PowerCenter are:
- Standard Edition
- Advance Edition
- Premium Edition
The current version of PowerCenter available is v10 with a high-performance increase.
Q11 : How can we create Index after completion of Load Process?
A : Command Tasks are used to create Index. Command Task scripts can be used in a session of workflow to create an index.
Q12 : What is Mapping?
A : Mapping is a collection of source and targets which are linked with each other through certain sets of transformations such as Expression Transformation, Sorter Transformation, Aggregator Transformation, Router Transformation etc.
Q13 : What is the format of INFORMATICA objects in a repository? What are the databases that INFORMATICA can connect to Windows?
A : INFORMATICA objects can be written in XML format.
Following is the list of databases that INFORMATICA can connect to:
- SQL Server
- Oracle
- MS Access
- MS Excel
- DB2
- Sybase
- Teradata
Q14 : What is Transformation?
A : Transformation can be defined as a set of rules and instruction that are to be applied to define data flow and data load at the destination.
Q15 : What is Sorter Transformation?
A : Sorter Transformation is used to sort large volume of data through multiple ports. It is much likely to work as the ORDER BY Clause in SQL. Sorter Transformation can be Active, Passive or Connected.
Active Transformation passes through Mapping and changes a number of rows whereas Passive Transformation passes through Mapping but does not change the number of rows.
Most of the INFORMATICA Transformations are Connected to the Data Path.
Q16 : What is Rank Transformation?
A : Rank Transformation is Active as well as Connected. It is used to sort and rank a set of records either top or bottom.
Rank Transformation is also used to select data with a largest or smallest numeric value based on a specific port.
Q17 : What is Update Strategy Transformation?
A : Update Strategy in Informatica is used to control data passing through it and tag it such as INSERT, UPDATE, DELETE and REJECT. We can set a conditional Logic within the Update Strategy Transformation to tag it.
Q18 : What is Status Code in INFORMATICA?
A : Code provides Error Handling Mechanism during each session. Status Code is issued by stored Procedure to recognize whether it is committed successfully or not and provides information to the INFORMATICA server to decide whether the session has to be stopped or continued.
Q19 : What is Mapplet in INFORMATICA?
A : Mapplet is a reusable object in INFORMATICA that contains a certain set of rules for transformation and transformation logic that can be used in multiple mappings. Mapplet is created in Mapplet Designer in the Designer Tool.
Q20 : What are Junk Dimensions?
A : Junk Dimension is a structure that consists of a group of some junk attributes such as random codes or flags. It forms a framework to store related codes with respect to a specific dimension at a single place instead of creating multiple tables for the same.
Q21 : What is Router Transformation?
A : Router Transformation is used to filter the source data. You can use Router Transformation to split out a single data source.
It is much like Filter Transformation but the only difference is that Filter Transformation uses only one transformation condition and returns the rows that do not fulfill the condition, Whereas Router Transformation uses multiple transformation conditions and returns the rows that match even a single condition.
Q22 : What is Expression Transformation?
A : It is a mapping transformation which is used to transform data in one record at a time. Expression Transformation can be passive or connected. The expression is used for data manipulation and output generation using conditional statements.
Q23 : What is Union Transformation in INFORMATICA?
A : Union Transformation is used to combine the data from different sources and frame it with the same port and data type. It is much like a Clause in SQL.
Q24 : How you can differentiate between Connected LookUp and Unconnected LookUp?
A : Connected Lookup is part of the data flow which is connected to another transformation, it takes data input directly from another transformation which performs a lookup. It uses both static and dynamic Cache.
Unconnected Lookup does not take the data input from another transformation but it can be used as a function in any transformation using LKP(LookUp) Expression. It uses the only static cache.
Q25 : How to elaborate Tracing Level?
A : Tracing Level can be defined as the amount of information that the server writes in the log file. Tracing Level is created and configured either at the transformation level or at session level else at both the levels.
Given below are the 4 types of tracing level:
- None
- Terse
- Verbose Initialization
- Verbose Data
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