ODI Developer Interview Questions and Answers

Slowly changing dimension (SCD) is a concept in data warehousing that describes how dimensions change over time.

• SCD Type 1: Overwrites old data with new data, losing historical information.

• SCD Type 2: Keeps multiple versions of the same dimension, creating new records for each change.

• SCD Type 3: Keeps both old and new values in the same record, with separate columns for each version.

• SCD Type 4: Uses separate tables to store historical and current data.

• SCD Type 6: Hybrid appro...read more

Check Knowledge Module is used in ODI to validate data before loading it into target tables.

• It is used to perform data quality checks on the source data

• It can be used to check for duplicates, missing values, data format, etc.

• It helps ensure that only clean and accurate data is loaded into the target tables

There are three types of LKM used in file to file loads: LKM File to SQL, LKM SQL to File, and LKM File to File.

• LKM File to SQL is used to load data from a file to a SQL database

• LKM SQL to File is used to extract data from a SQL database to a file

• LKM File to File is used to move data from one file to another

CDC stands for Change Data Capture. It is a technique used to capture and propagate changes made to data in a database.

• CDC captures changes made to data in a database and propagates them to other systems.

• There are two types of CDC: Log-based CDC and Trigger-based CDC.

• Log-based CDC reads the transaction log of a database to capture changes.

• Trigger-based CDC uses triggers to capture changes made to specific tables.

• CDC is commonly used in data integration and replication scenari...read more

A package in ODI is a container that holds related objects and components for organizing and managing data integration processes.

• Packages are used to group together related objects such as interfaces, procedures, variables, and more.

• They provide a way to organize and manage data integration processes in ODI.

• Packages can be used to define the execution order of objects within a process flow.

• They can be scheduled for automatic execution or manually triggered.

• Packages can be exp...read more

SCD stands for Slowly Changing Dimensions. It is a technique used in ODI to handle changes in data over time.

• SCD is used to track and manage changes in dimension tables

• It helps in maintaining historical data and tracking changes in attributes

• There are different types of SCDs, such as Type 1, Type 2, and Type 3

• Type 1 SCD overwrites the existing data with the new data

• Type 2 SCD creates a new record for each change and maintains a history

• Type 3 SCD adds additional columns to tra...read more

Knowledge Modules in ODI are reusable components that define the logic for performing specific tasks in the ETL process.

• Types include Loading Knowledge Modules, Integration Knowledge Modules, Check Knowledge Modules, Reverse-Engineering Knowledge Modules, and Service Knowledge Modules.

• Loading Knowledge Modules handle data loading into target tables.

• Integration Knowledge Modules handle data integration between source and target tables.

• Check Knowledge Modules perform data quali...read more