Forum Discussion
Impactful IndividualReporting Views
what is the deciding factor for creating views in datawarehouse for reporting purpose, how i would know whether i should create view , as far as i know views are created for performance enahancement purpose and only static calculations can be implemented in view
Hi powerbiexpert22 - A view is generally not created for performance enhancement. A normal SQL view is primarily an abstraction/reusability/security/semantic layer. In most database engines, the underlying query is expanded into the execution plan, so simply putting a query into a view does not inherently make it faster. A normal view doesn't necessarily mean the database first generates the entire view and then filters it.
Note: Create a view when you need a reusable, governed and stable logical representation of warehouse data - not simply because you expect better performance.
Hope this helps.
3 Replies
- rajendraongole1
Super User
Hi powerbiexpert22 - A view is generally not created for performance enhancement. A normal SQL view is primarily an abstraction/reusability/security/semantic layer. In most database engines, the underlying query is expanded into the execution plan, so simply putting a query into a view does not inherently make it faster. A normal view doesn't necessarily mean the database first generates the entire view and then filters it.
Note: Create a view when you need a reusable, governed and stable logical representation of warehouse data - not simply because you expect better performance.
Hope this helps.
- krishnakanth240
Views are created for abstraction and reusability. View is a stored query that runs at execution time, so it won't speed up. Create a view when you want to hide complex joins so multiple reports stay consistent. Also, Views are not limited to static calculations as they can include joins, aggregations and window functions as SQL runs each time so limitation is that they become inefficient over large datasets when queried repeatedly which is when a materialized view is the approach
- ShivekMaharaj
Community Champion
Hi powerbiexpert22,
I agree with the points already made. I would add one Fabric-specific distinction because it helps with the decision.
In Fabric Warehouse, I would not create a normal view primarily for performance.
Microsoft currently does not support materialized views in Fabric Warehouse, and indexed views are also unsupported. A normal view is therefore still essentially a stored query definition rather than a persisted copy of the result.
That means a complex query does not automatically become faster simply because it is wrapped in a view.
would normally create a view when I need things such as:
- reusable joins or business logic
- a stable reporting interface over underlying tables
- simpler objects for report developers to consume
- consistent naming or calculated fields
- a governed logical layer so several reports use the same query logic
Views are also not limited to static calculations. Microsoft's Fabric Warehouse examples include views with joins, aggregations, GROUP BY and other normal T-SQL logic.
The view is evaluated against the underlying data when it is queried, so if the source data changes, the result returned by the view changes as well.
For example, Microsoft's Warehouse time-travel tutorial creates a reporting view using a join, SUM and GROUP BY.
If you have an expensive transformation or aggregation that is queried repeatedly and performance is the main concern, I would consider whether that result should instead be physically persisted into a reporting table and refreshed as part of the data pipeline.
Fabric's SQL query editor supports saving query results as a table, which persists the output rather than recalculating the complete query every time.
For performance tuning in the Warehouse itself, I would also look at the areas Microsoft covers in the Fabric Warehouse performance guidance, such as statistics, caching, query plans and data layout, rather than expecting the view itself to provide the optimization.
So my rule of thumb would be:
- use a view for abstraction, reuse and a stable reporting contract
- use a physical reporting table when you deliberately want to persist expensive transformation/aggregation results
- tune the underlying Warehouse query separately when performance is the actual issue
AI-assisted drafting: AI was used to help structure and phrase this response. I reviewed and validated the technical content before posting.
