Choosing the right Data Warehouse SQL Engine: Apache Hive LLAP vs Apache Impala

Some of the most powerful results come from combining complementary superpowers, and the “dynamic duo” of Apache Hive LLAP and Apache Impala, both included in Cloudera Data Warehouse, is further evidence of this. Both Impala and Hive can operate at an unprecedented and massive scale, with many petabytes of data. Both are 100% Open source, so you can avoid vendor lock-in while you use your favorite BI tools, and benefit from community-driven innovation.

ETL Testing: What, Why, and How to Get Started

Companies use their data to accelerate business growth and overtake their competitors. To achieve this, they invest a lot in their ETL (extract-transform-load) operations, which take raw data and transform it into actionable information. It’s no wonder, then, that ETL testing is a crucial part of a well-functioning ETL process, since the ETL process generates mission-critical data.

Databases Demystified Lesson 10: Query Planning and Optimization

In this lesson, we talk about what a query planner is and does in the database. We talk about the difference between declarative and imperative programming languages, and we wrap up with a discussion of some common strategies for database optimization to improve query speed.