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Isolated query of a joint view

Hello, is it possible to solve the following scenario: I have two views with different sources, which I would like to join (a push-down is therefore not possible). I want to join these views and make them available for reporting. However, the reporting now only wants to query one column from this view. Denodo executes this query on the correct source, but still pulls data from the other source to join it. Is it somehow possible to skip this join and actually run this one column without using the other source and without having to build a new view? This would drastically increase my performance at least for this scenario. However, I can also understand that this requirement may not be immediate, hence my question if this could not be switched on somehow. Kind regards
user
14-04-2021 11:47:21 -0400

1 Answer

Hi, The Denodo engine performs static optimizations such as **Branch pruning, Aggregation Push down**,.. to improve the query performance. However, it is necessary for the optimizer to apply some optimizations only if the view definition has certain constraints. For this scenario, I would define **[associations](https://community.denodo.com/docs/html/browse/8.0/en//vdp/administration/restful_architecture/associations/associations#associations)** between the join views by which the query optimizer will perform **[Branch pruning](https://community.denodo.com/docs/html/browse/8.0/en//vdp/administration/optimizing_queries/automatic_simplification_of_queries/removing_redundant_branches_of_queries_partitioned_unions#removing-redundant-branches-of-queries-partitioned-unions)** optimization to prune the delegation to the other data source. For more information on branch pruning optimizations, you can take a look at the **[Associations in Denodo](https://community.denodo.com/kb/view/document/Associations%20in%20Denodo?category=Combining+Data)** and **[Denodo Query Optimizations for the Logical Data Warehouse](https://community.denodo.com/kb/view/document/Denodo%20Query%20Optimizations%20for%20the%20Logical%20Data%20Warehouse?category=Performance+%26+Optimization)** Knowledge Base Articles. Hope this helps!
Denodo Team
16-04-2021 08:35:01 -0400
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