🏭🗒️Microsoft Fabric: Materialized Lake Views (MLV) [Notes] 🆕🗓️

Disclaimer: This is work in progress intended to consolidate information from various sources for learning purposes. For the latest information please consult the documentation (see the links below)! 

Last updated: 24-May-2025

-- create schema
CREATE SCHERA IF NOT EXISTS <lakehouse_name>.<schema_name>

-- create a materialized view
CREATE MATERIALIZED VIEW IF NOT EXISTS <lakehouse_name>.<schema_name>.<view_name> 
(
    CONSTRAINT <constraint_name> CHECK (<constraint>) ON MISMATCH DROP 
) 

AS 
SELECT ...
FROM ...
-- WHERE ...
--GROUP BY ...

[Microsoft Fabric] Materialized Lake Views (MLV)

• {def} persisted, continuously updated view of data [1]
• {benefit} allows to build declarative data pipelines using SQL, complete with built-in data quality rules and automatic monitoring of data transformations
• simplifies the implementation of multi-stage Lakehouse processing [1]
• streamline data workflows
• enable developers to focus on business logic [1]
• ⇐ not on infrastructural or data quality-related issues [1]
• the views can be created in a notebook [2]
• can have data quality constraints enforced and visualized for every run, showing completion status and conformance to data quality constraints defined in a single view [1]
• empowers developers to set up complex data pipelines with just a few SQL statements and then handle the rest automatically [1]
• faster development cycles 
• trustworthy data
• quicker insights
• {goal} process only the new or changed data instead of reprocessing everything each time [1]
• ⇐  leverages Delta Lake’s CDF under the hood
• ⇒ it can update just the portions of data that changed rather than recompute the whole view from scratch [1]
• {operation} creation
• allows defining transformations at each layer [1]
• e.g. aggregation, projection, filters
• allows specifying certain checks that the data must meet [1]
• incorporate data quality constraints directly into the pipeline definition
• via CREATE MATERIALIZED LAKE VIEW
• the SQL syntax is declarative and Fabric figures out how to produce and maintain it [1]
• {operation} refresh
• refreshes only when its source has new data [1]
• if there’s no change, it can skip running entirely (saving time and resources) [1]
• {feature} automatically generate a visual report that shows trends on data quality constraints 
• {benefit} allows to easily identify the checks that introduce maximum errors and the associated MLVs for easy troubleshooting [1]
• {feature} can be combined with Shortcut Transformation feature for CSV ingestion 
• {benefit} allows building an end-to-end Medallion architecture
• {feature} dependency graph
• allows to see the dependencies existing between the various objects [2]
• ⇐ automatically generated [2]
• {feature} data quality report
• built-in Power BI dashboard that shows several aggregated metrics [2]
• {feature|planned} support for PySpark
• {feature|planned} incremental refresh
• {feature|planned} integration with Data Activator

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References:

[1] Microsoft Fabric Update Blog (2025) Simplifying Medallion Implementation with Materialized Lake Views in Fabric [link|aka]

[2] Power BI Tips (2025) Microsoft Fabric Notebooks with Materialized Views - Quick Tips [link]

[3] Microsoft Learn (2025)  [link]

Resources:
[R1] Databricks (2025) Use materialized views in Databricks SQL [link]

Acronyms:

CDF - Change Data Feed

ETL - Extract, Transfer, Load

MF - Microsoft Fabric
MLV - Materialized Lake views