20 TOP Ab Initio Interview Questions and Answers pdf

Most frequently Asked Ab Initio Interview Questions and Answers for freshers and experienced pdf free download
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.

11. What is the syntax of m_dump command?
The genaral syntax is "m_dump metadata data [action] "

12. How Does MAXCORE works?
Maxcore is a value (it will be in Kb).Whne ever a component is executed it will take that much memeory we specified for execution

13. What is the Difference between DML Expression and XFR Expression?
The main difference b/w dml & xfr is that
DML represent format of the metadata.
XFR represent the tranform functions.which will contain business
rules

14. I am unable to connect sever database(oracle) from GDE(db config file) local system.i set all these?
ChalapathiFirst we can check the properties in internet options and then u can check in cmd format telenet abinitio ip_add.

15. What is $mpjret? Where it is used in ab-initio?
You can use $mpjret in endscript like
if 0 -eq($mpjret)
then
echo "success"
else
mailx -s "[graphname] failed" mailid

16. What is the latest version that is available in Ab-initio?
The latest version of GDE ism1.15 AND Co>operating system is 2.14

17. What is AB_LOCAL expression where do you use it in ab-initio?
ablocal_expr is a parameter of itable component of Ab Initio.ABLOCAL() is replaced by the contents of ablocal_expr.Which we can make use in parallel unloads.There are two forms of AB_LOCAL() construct, one with no arguments and one with single argument as a table name(driving table).
The use of AB_LOCAL() construct is in Some complex SQL statements contain grammar that is not recognized by the Ab Initio parser when unloading in parallel. You can use the ABLOCAL() construct in this case to prevent the Input Table component from parsing the SQL (it will get passed through to the database). It also specifies which table to use for the parallel clause.

18. How do you convert 4-way MFS to 8-way mfs?
To convert 4 way to 8 way partition we need to change the layout in the partioning component. There will be seperate parameters for each and every type of partioning eg. AI_MFS_HOME, AI_MFS_MEDIUM_HOME, AI_MFS_WIDE_HOME etc.
The appropriate parameter need to be selected in the component layout for the type of partioning.

19. Have you used rollup component? Describe how?
If the user wants to group the records on particular field values then rollup is best way to do that. Rollup is a multi-stage transform function and it contains the following mandatory functions.
1. initialise
2. rollup
3. finalise
Also need to declare one temporary variable if you want to get counts of a particular group.
For each of the group, first it does call the initialise function once, followed by rollup function calls for each of the records in the group and finally calls the finalise function once at the end of last rollup call.

20. What are primary keys and foreign keys?
In RDBMS the relationship between the two tables is represented as Primary key and foreign key relationship.Wheras the primary key table is the parent table and foreignkey table is the child table.The criteria for both the tables is there should be a matching column.