Chapter 1: Understanding Change Data Capture

Google has recently enhanced its Software as a Service (SaaS) Data Warehouse, BigQuery, by introducing Change Data Capture (CDC). This feature facilitates the real-time processing and application of streamed modifications to existing datasets via the BigQuery Storage Write API.

Capturing changes made to a database is crucial for tracking and replicating data in real-time. CDC is widely employed in data integration, warehousing, and analytics, ensuring synchronization across various systems. One significant advantage of CDC is its ability to empower organizations to make informed, data-driven decisions using the latest information.

Section 1.1: Real-Time Data Access Benefits

With CDC, businesses can harness real-time data, enabling them to make quicker, more informed choices and enhance overall operational effectiveness.

CDC within BigQuery — Image Source: Google

The BigQuery Storage Write API serves as a comprehensive data ingestion tool, merging streaming ingestion with batch loading into one high-efficiency API. Users can employ this API to stream data into BigQuery in real-time or to process numerous records simultaneously, committing them in a single atomic transaction. To utilize BigQuery's CDC, certain prerequisites must be met:

1. The Storage Write API should be used in the default stream.
2. Primary keys for the destination table in BigQuery must be declared, with support for composite primary keys encompassing up to 16 columns.

Subsection 1.1.1: Clustering and Resource Requirements

Moreover, the destination table in BigQuery needs to be clustered, and adequate computing resources must be available to execute the CDC operations effectively. This new functionality is particularly beneficial for Data Engineers, although it is currently in preview mode.

Chapter 2: Exploring Additional Features in BigQuery

The first video titled GCP - BigQuery CDC delta load logic (Change Data Capture) - DIY#8 - YouTube delves into the intricacies of implementing CDC in BigQuery, showcasing practical applications and strategies.

The second video, How to perform CDC from PostgreSQL to Big Query by using DataStream in Google Cloud Platform - YouTube, provides a comprehensive guide on migrating data using DataStream, enhancing your understanding of CDC implementation.