great_expectations: Your data validation with guarantee on high quality data.

Data analysts typically define clear expectations for the data they use, such as data types, value ranges, relationships between columns, and data validity. With great_expectations, analysts can identify problems in their data pipeline at an early stage and thus reduce the risk that important business decisions are made on the basis of inaccurate or wrong data.

What is great_expectations?

great_expectations is an open-source Python package that helps data teams build reliable and maintainable data pipelines. It provides a framework for defining, managing, and validating data expectations across multiple sources, data types, and data processing systems.

The tool provides a flexible and extensible Expectations syntax, by means of which complex expectations on data can be defined. This language supports a variety of data types, operators, and functions that can be used to easily express complex relationships between data. Once expectations are defined, they can be used to validate data as it passes through a pipeline. great_expectations provides a set of data validation tools that can be used to validate data types, value ranges, relationships between columns, and more. Validation results can be visualized with the built-in data quality dashboard, making it easy to see where data quality issues are occurring.

In addition, the ability to define and manage expectations in a structured, version-driven manner can help improve the maintainability and reliability of data pipelines over time.

What are the advantages of this solution?

Modularity

great_expectations is highly modular and customizable, so it can be easily adapted to the individual requirements of a company and its diverse data sources.

Integration

The tool integrates with a variety of data processing tools, including Apache Spark, Pandas, Snowflake and others. This makes it easy to incorporate great_expectations into existing data processing workflows.

Improved data quality

By defining expectations for data using great_expectations, data quality issues can be identified early in the data pipeline.

Collaboration

great_expectations provides a framework for defining and managing expectations that can be easily shared and version controlled. This can help improve collaboration between data teams, reduce the risk of duplication, and increase transparency.

Cost efficiency

The library is open source and provides a set of tools to automate data validation and documentation tasks, saving time and reducing the workload of data teams.

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Features of great_expectations

Data quality dashboard

The data quality dashboard in great_expectations provides a user-friendly interface to monitor the quality of data over time. The dashboard displays key metrics, such as the number as well as the percentage of rows that meet or do not meet expectations. Developers can also view detailed information about individual expectations and drill down into specific data sets to understand the root cause of data quality issues. The dashboard can help data teams quickly identify and resolve data quality issues to improve the accuracy and reliability of their data.

Automated data documentation

great_expectations includes automated data documentation tools that can be used to create comprehensive documentation for data pipelines. This documentation includes information such as the schema of the data, descriptive statistics, and sample data. The documentation is automatically created based on the expectations defined for the data, so it is always up-to-date and accurate. This can help analysts better understand their data and make informed decisions based on that data.

Data Profiling

The library provides tools for creating data profiles, which can be used to better understand the structure and characteristics of data. These tools can be used to identify patterns in the data, such as value distributions, missing values and more. Data profiling can help data teams identify data quality issues and potential data biases to improve data accuracy and reliability. Profiling results can also be visualized with the data quality dashboard, making these findings easy to understand and share with stakeholders.

Alerting and notification

Alerting and notification tools are also components of great_expectations, these can be used to notify teams when data quality issues occur. You can set up notifications for specific expectations or data batches and be notified via email, Slack, or other messaging platforms. This allows analysts to quickly identify and resolve data quality issues before they impact downstream processes. Alerts and notifications can also be used to provide real-time feedback on data quality to improve the overall reliability of data pipelines.

Use cases of the solution

One way to validate data in real time is to use Cloud Pub/Sub and Cloud Functions in combination with great_expectations. Cloud Pub/Sub is a messaging service that enables decoupled and asynchronous communication between components of an application, while Cloud Functions is a serverless computing service that enables code execution in response to events.

In this use case, data is published to a cloud pub/sub topic and a cloud function is triggered to perform great_expectations validations on the incoming data. If the data passes validation, it can be stored in a database or sent to downstream processes. If the data does not pass validation, an alert can be sent to notify the appropriate personnel. This use case ensures that data quality issues can be identified early in the pipeline and resolved in real time, reducing the risk of making decisions based on inaccurate data.

A data lake is a central repository where data from various sources can be stored in its raw and unstructured format. great_expectations can be used to monitor data quality in a data lake by connecting to the storage layer of the data lake (e.g. Google Cloud Storage) and defining expectations for the data. Expectations can be defined for various aspects of the data, such as data types, value ranges, and relationships between columns.

great_expectations can then be set up to perform regular validations in the data lake and display any issues in the data quality dashboard. This use case helps ensure that data quality issues are identified early in the pipeline and that the data in the data lake is of high quality and suitable for use.

BigQuery is a serverless, highly scalable and cost-effective data warehouse that enables the analysis of large data sets with SQL-like queries. great_expectations can be used to automate data validation in BigQuery by defining expectations for the data. For this, a great_expectations data source must be created for BigQuery and the data source is used to perform validations on the data in BigQuery.

The results of the validations can be displayed in the data quality dashboard and can also trigger notifications if the data does not withstand the validations. In this setup, it is ensured that the data in BigQuery is accurate, reliable and consistent as well as reducing the need for manual data validation processes.

During data preprocessing, raw data is cleaned and converted into a format that can be used by downstream processes, such as machine learning models. great_expectations can be used to validate data in data preprocessing pipelines by defining expectations for the data and performing validations on the data as it passes through the pipeline. For example, if a machine learning model requires numerical data, great_expectations can be used to ensure that the data is indeed numerical before it is passed to the model. This deployment option helps ensure that the data used by downstream processes is of high quality and reduces the risk of inaccurate results.

Without great_expectations, what opportunities are you missing?

Without great_expectations, organizations miss a valuable opportunity to ensure the accuracy and reliability of their data pipelines. With great_expectations' powerful data validation capabilities, analysts can define expectations for their data and validate them as they move through their pipeline. This identifies data quality issues early and reduces the risk of making decisions based on inaccurate data.

By using great_expectations, organizations can also automate their data documentation so that employees can more easily understand and use data for better decision making. In addition, the platform provides data profiling tools that help better understand the structure and characteristics of data so that patterns and potential data quality issues can be identified.

In addition, great_expectations integrates seamlessly with Google Cloud Platform services such as BigQuery and Dataflow, giving teams the scalability and flexibility they need to handle large-scale data projects. With its alerting and notification capabilities, they can also get real-time feedback on the quality of the data, ensuring that it is always accurate and up-to-date.

Increase the value and reliability of your data with great_expectations to stay ahead of the competition.

KNOWLEDGE

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