ETL Interview Questions

9.5.1

9.5

Yes, ODS is a Open Data Source where it contains real time data (because we should apply any changes on real time data right..!) so dump the real time data into ODS called Landing area later we get the data into staging area here is the place where we do all transformation.

ODS (Operational Data Source) is the first point in the Datawarehouse. Its store the real time data of daily transactions as the first instance of Date.

Add InetSofts Style Report to the list of BI reporting tools

Hi, i would like share my knowledge on this. ETL Tools: Ab Initio, BusinessObjects Data Integrator, IBM InfoSphere DataStage, Informatica, Oracle Warehouse Builder, SQL Server In...

Data-Centric Testing: Data-centric testing revolves around testing quality of the data. The objective of the data-centric testing is to ensure valid and correct data is in the system. Following are th...

Run a Minus query between source and target

Data Quality checks come in a number of forms:- 1. For FACT table rows, is there a valid lookup against each of the Dimensions 2. For FACT or DIMENSION rows, for each value:- Is it Null when it shoul...

ETL Testing in Informatica: 1. First check the workflow exist in specified folder. 2. Run the workflow. If the workflow is success then check the target table is loaded on proper data else we can nee...

- Test ETL software. - Test ETL datawarehouse components. - Executing backend data-driven test. - Create, design and execute test plans, test harnesses and test cases. - Identify, troubleshoot and pro...

Hi, If you even do dynamic lookup you should make use of update strategy to mark the records either to insert or update in the target using look-up cache (look-up will be cached on target). your re...

Update strategy transformation determines whether to insert, update, delete or reject a record for the target.  We can bypass update strategy transformation by creating a router to divide ro...

Data Cleansing is a process of detecting and correcting the corrupt and inaccurate data from table or database.
There are following steps used:-
1) Data auditing
2) Workflow Specification
3) Workflow Execution
4) Post-processing and controlling

Cleaning is required as it helps in maintaining the uniforminty of the target data.

Conditional statements are also given in the Expression transformation then why it is passive transformation....

Active transformation is nothing but it will change the no of rows passing through it (example) Filter transformation .In it when  we have 1000 rows as input after filter transformation according...

Some of the ETL Testers Responsibilities are as follows: - Test ETL software. - Test ETL datawarehouse components. - Executing backend data-driven test. - Create, design and execute test plans, test ...

Generally, the flat file data is populated into the table and then loaded into the target based on transformations. It would then be the same process how we validate the data. Pls correct me if am not correct...

I assume your source flat file is on UNIX box and the first row has column name seperaetd by space - then -

$ head -1 | wc -w

Use the indirect filelist option at informatica session. say the filelist name is daily_file.txt put a shell script daily_filename.sh at the pre-session command. The content of daily_filename.sh is ...

You can use Informatica File List option in target to get the dynamic file names along with the transaction control transformation so that you can create dynamic filenames based on some transaction properties.....

The main difference between connected and unconnected lookup is, we can call unconnected lookup based on some conditions but not the connected lookup.

Lookup can be used as Connected or Unconnected. Apart from cache and receiving input values from pipe line, there is one more difference. If you want to use the same lookup more than one in a mapping ...

I think in microstrategy view can be reusable object.

SIMPLY to say::::::::::::::::::

worklet : set of sessions

mapplet : set of transformations that can be called within a mapping

mapping :-set of transformations.And moving data from source to target along with transformation s

session :-set of instructions source addresses and target address u write it

worklet:- set of sessions

aggregator
joiner
lookup
rank
sorter

Actually the answer is partially related to the Question.......

t/rs like Joiner, Lookup, Aggregator,Rank Transformations uses the Caches.....

You can use a Command task to call the shell scripts, in the following ways: 1. Standalone Command task. You can use a Command task anywhere in the workflow or worklet to run shell commands. 2. Pr...

Hi,There are two ways to do this,they are as follows:1)we can use a command task anywhere  in the workflow or worklet to run the shell commands.2)In the session task,we can call reusable command ...

Oracle provides partitioning of Tables, Indexes and IOTs to split their contents into different partitions.  Each partition could be on a separate physical drive.  This provides faster perfo...

There are 4 types of partitioning

they are 1)pass through 2)Round Robin 3)hash 4)Key range partition