HCL Group Datastage Developer Interview Questions and Answers

Transformer stage is a Datastage stage used for data transformation and manipulation.

• Transformer stage is used to perform complex data transformations and manipulations.

• It allows users to define custom logic using graphical mapping.

• It supports various functions and operators for data manipulation.

• Transformer stage can be used to filter, aggregate, join, and sort data.

• It can also be used to perform calculations, convers...read more

Use Datastage to remove duplicates from a dataset

• Use a Remove Duplicates stage in Datastage to eliminate duplicate records

• Configure the Remove Duplicates stage to identify and remove duplicates based on specific key columns

• Ensure that the dataset is sorted properly before applying the Remove Duplicates stage

Yes, you can send attachments in DataStage using email notifications or external scripts.

• Use the DataStage job properties to configure email notifications.

• Utilize the 'Email' stage to send emails with attachments.

• Integrate with external scripts (e.g., Python, Shell) to handle file attachments.

• Example: In the Email stage, specify the attachment path in the 'Attachments' field.

To get reject records in DataStage, use filters and stages like Transformer to identify and separate invalid data.

• Use a Transformer Stage: Implement a Transformer stage to apply conditional logic that identifies records that do not meet specific criteria.

• Filter Stage: Utilize a Filter stage to exclude valid records based on defined conditions, allowing only reject records to pass through.

• Stage Variables: Create stage v...read more

Join is used to combine rows from two or more tables based on a related column, while lookup is used to retrieve data from a reference table based on a matching key.

• Join combines rows from multiple tables based on a related column

• Lookup retrieves data from a reference table based on a matching key

• Join can result in duplicate rows if there are multiple matches, while lookup returns only the first matching row

• Join is use...read more

Fact table contains quantitative data and measures, while dimension table contains descriptive attributes.

• Fact table contains numerical data that can be aggregated (e.g. sales revenue, quantity sold)

• Dimension table contains descriptive attributes for analysis (e.g. product name, customer details)

• Fact table is typically normalized, while dimension table is denormalized for faster queries

• Fact table is usually larger in s...read more

Use sed command to display the line before a specific pattern

• Use 'sed -n '/pattern/{g;1!p;};h' file.txt' to display the line before the pattern

• Replace 'pattern' with the specific pattern you are looking for

• This command will display the line before the pattern in the file