Q1. What is dimensional modelling in a Data Warehouse (i.e. DWH)?
A1. A dimensional model is a data structure technique optimised for Data Warehousing tools (i.e. OLAP products). The concept of Dimensional Modelling is comprised of Fact and Dimension tables.
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This extends Q1 to Q5 at 13 Data Warehouse interview Q&As – Fact Vs Dimension, CDC, SCD, etc – part 1. Q6. What is a Factless Fact table? A6. From the above store sales example we know that fact table is a collection of many facts having multiple keys joined...
SQL interview Questions & Answers is a must for any developer as all non-trivial applications need to talk to a database with CRUD operations. Q3 – Q15 are very popular with the interviewers. If you want to quickly practice your SQL skills try DB Fiddle or install MySQL locally as shown in the ⏯ MySQL database beginner video tutorial.
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Q01. Can you summarise the Spark eco system?
A01. Apache Spark is a general purpose cluster computing system. It provides high-level API in Java, Scala, Python, and R. It has 6 components Core, Spark SQL, Spark Streaming,
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Modern data architectures will have both the Data Lakes and Data Warehouses. The Data Engineers build the data pipelines for the data analysts and scientists to build business reports & models to analyse the data.
Q01. What is a Data Lake?
A01.
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There are a number of technologies to ingest & run analytical queries over Big Data (i.e. large volume of data). Big Data is used in Business Intelligence (i.e. BI) reporting, Data Science, Machine Learning, and Artificial Intelligence (i.e. AI). Processing a large volume of data will be intensive on disk I/O,
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Q1. What is data backfilling? A1. Backfilling data is a process of reactively processing any missing data for a past time window. Q2. Why do you need to backfill data? A2. … Read more ›...
15+ SQL interview questions and answers to solve real business scenarios. SQL is widely used in building microservices & Big Data projects. Learning SQL syntax is easy, but being able to convert a given business requirement into a query takes lots of practice. These scenarios based interview questions can assesses your experience.
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Apache Kafka is used in Micro Services Architecture (i.e. MSA) to Big Data & Low Latency application architectures. Q1. What is Apache Kafka? A1. Apache Kafka is a distributed messaging broker. The purpose of the Kafka project is to provide a unified, … Read more ›...
The above diagram addresses many of the questions that follow. Q1. What is a VPC in AWS? A1. A virtual private cloud (VPC) is a virtual network dedicated to your AWS account. It is logically isolated from other virtual networks in the AWS Cloud. … Read more ›...