Top Ab Initio Interview Questions & Answers:

1. How to get DML using Utilities in UNIX?

If your source is a cobol copybook, then we have a command in unix which generates the required in Ab Initio. here it is:

cobol-to-dml.

2. What is skew and skew measurement?

skew is the mesaureof data flow to each partation .

suppose i/p is comming from 4 files and size is 1 gb

1 gb= ( 100mb+200mb+300mb+5oomb)

1000mb/4= 250 mb

(100- 250 )/500= --> -150/500 == cal ur self it wil come in -ve value.

calclu for 200,500,300.

+ve value of skew is allways desriable.

skew is a indericet measure of graph.

3. What is the difference between a Scan component and a RollUp component?

Rollup is for group by and Scan is for successive total. Basically, when we need to produce summary then we use scan. Rollup is used to aggregate data.

4. What is m_dump?

m_dump command prints the data in a formatted way.

m_dump <dml> <file.dat>

5. What is the importance of EME in abinitio?

EME is a repository in Ab Inition and it used for checkin and checkout for graphs also maintains graph version.

6. What is BRODCASTING and REPLICATE?

Broadcast - Takes data from multiple inputs, combines it and sends it to all the output ports.

Eg - You have 2 incoming flows (This can be data parallelism or component parallelism) on Broadcast component, one with 10 records & other with 20 records. Then on all the outgoing flows (it can be any number of flows) will have 10 + 20 = 30 records

Replicate - It replicates the data for a particular partition and send it out to multiple out ports of the component, but maintains the partition integrity.

Eg - Your incoming flow to replicate has a data parallelism level of 2. with one partition having 10 recs & other one having 20 recs. Now suppose you have 3 output flos from replicate. Then each flow will have 2 data partitions with 10 & 20 records respectively.

7. What is local and formal parameter?

Two are graph level parameters but in local you need to initialize the value at the time of declaration where as globle no need to initialize the data it will promt at the time of running the graph for that parameter.

8. How to run the graph without GDE?

In RUN ==> Deploy >> As script , it create a .bat file at ur host directory ,and then run .bat file from Command prompt

9. What are differences between different GDE versions(1.10,1.11,1.12,1.13and 1.15)?
What are differences between different versions of Co-op?

1.10 is a non key version and rest are key versions.

There are lot of components added and revised at following versions.

10. Can anyone give me an exaple of realtime start script in the graph?

Here is a simple example to use a start script in a graph:

In start script lets give as:

export $DT=`date '+%m%d%y'`

Now this variable DT will have today's date before the graph is run.

Now somewhere in the graph transform we can use this variable as;

out.process_dt::$DT;

which provides the value from the shell.