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Disadvantage of using multiple CTEs in Denodo

We are using many level of CTEs in our architeture.Also joining them with other integrated views.Please let me know what are the disadvantages of using CTEs in Denodo considering performance side.
CTE
user
22-09-2020 07:34:04 -0400

1 Answer

Hi, According to the [WITH Clause](https://community.denodo.com/docs/html/browse/7.0/vdp/vql/queries_select_statement/with_clause/with_clause) section of the Virtual DataPort Administration guide, advantage of the CTE's is that they improve the readability and maintenance of complex queries. Talking about limitations, the same disadvantages that apply to CTE's outside of Denodo are relevant for CTE's within Denodo as well. The performance would depend on how the CTE is being used. The data required to make a CTE still has to be queried and brought over a network. Also, if you are referencing it multiple times, it would be better to create a view instead that has statistics and indexes which help speed up query execution. To conclude, the performance aspect of a CTE depends on the data they pull in and what is done with it. Hope this helps!
Denodo Team
22-09-2020 17:48:01 -0400
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