Maximum number of DataStage Jobs in a project

Filesystems can have a hard limit on number of subdirectories that can be contained in a directory, for example 32766 (32K -2) for Linux

For every job, DataStage will create hash files as subdirectories in the project directory. Here is a list of the subdirectories created for every job. In this list "nn" represents the number (or id) of the job:

DS_TEMPnn

RT_CONFIGnn

RT_STATUSnn

RT_LOGnn

RT_BPnn

RT_BPnn.O

RT_SCnn (only for parallel jobs)

Get nth Highest or Lowest data from Table

Here, we are considering a table student and we need to find out Nth highest and lowest marks of a student.

Nth Highest

select * from student s1 where N-1 = ( select count(distinct(marks)) from student s2 where s1.marks > s2.marks)

SQL Scenario - 1

You have a table like below :

Name Age Gender
Atul         11 F
Ram 10 F
Disha  6 M
Pavan  8 F
Mani         10 M
Lovely 10 M
Rani    9 M

Unlocking XMETA locks from jobs

How can I unlock an XMETA locked job?

The job cannot be exported and when attempting to open the job, the following error appears:

Unable to open the Job
The Job 'TestJob' is locked by user 'dsadm'
(SessionID '8F1B0326-4F7E-45A8-B8EC-EAA8C4780528')

Do you want to continue and open a read-only view of the Job?

This issue arises when a lock still remains in XMETA for the corresponding job. Information Server will lock the job to ensure that there is no indeterminancy regarding the editing and saving of a job.
The most common causes of this is when a user has closed a client window unexpectedly (e.g. Force Terminate).

What happen when Import Sequential File with Extra Column

Job reads sequential file and load into RDBMS table.

What happen if sequential file has extra column in the back of each record?

It depends on data type of last column defined by DS and RDBMS table.

• If data type of last column = varchar, extra column will be included as last column.

DataStage Installation Checklist

• Review the system requirements.
• learn about tiers and components.
• Design the topology of your installation.
• Determine whether to pre-install your database system.
• Determine whether to pre-install IBM WebSphere Application Server or pre-configure an existing installation of WebSphere Application Server.

trim leading 0's from decimal in DataStage

1. Convert the decimal (or whatever it was) to String.
2. then trim '0's from left.

Installing PyMongo with MongoDB in Linux

1. Download Pymongo Source from HERE.
2. Then follow below steps --

Error - mongod shell doesn't start, /data/db doesn't exsist

Error - mongod shell doesn't start, /data/db doesn't exsist


If you face this error while starting MongoDB (mongod), most probably there are 2 reasons for this -

a.  /data/db is not exist at all
b. mongod process don't have access on /data/db

Solution :-

The default db path for mongodb is /data/db/.
So when you run:

MongoDB Configuration in Linux

DOWNLOAD the stable version of MongoDB. It will a tar file.

1. Create a folder named 'learn' ( or whatever you want to give )

     $ mkdir -p /learn/mongodb  /app/dbMongo

      # /learn/mongodb  = Holds the MongoDB source

      # /app/dbMongo = Holds the MongoDB database

2. Extract the Mongo DB zip file in /learn folder

  $ tar -xvf MongoDB.tar  /learn/mongodb

3.  change the permission of folder to user who run the db here-  In my case User - atul and Group - atul
  $ chown -R atul:atul  /learn/mongodb  /app/dbMongo

Trigger types in Sequencer Job

While designing Sequencer jobs when we are using any Sequencer Stage ( Job activity, Command activity or others ), it has a tab named 'trigger' which actually determine the actions that occur when the activity runs. Each activity can output different trigger types. 

Three types of triggers are available, with some types having subtypes.

Conditional

A conditional trigger runs the target activity if the source activity fulfills the specified condition. The condition is defined by an expression, and can be one of the following types: