Approach for better performance and queries

Hello
If I had two requests and they used as source an underlying query, better performance to create another underlying query for the second query?
Ben

Benton says:
If I had two requests and they used as source an underlying query, better performance to create another underlying query for the second query?

Which would reduce I/O?

Because that is what SQL performance tuning is usually about. E/s is slower and more expensive operation. Results of the huge hit to performance. This set of queries mean used these queries less i/o - a better way of I/O, which allows the query to obtain the required data using less I/O.

So in this context, your question seems absurd... Why get a "+ alternate copy + ' a subquery used, improve the performance of the 2nd query? It is not a question of the subquery have to redouble their efforts because it is used by both applications. It's about designing logically correct queries (which applies the correct thinking to produce correct results) and writing to use roads I/O best available such as implemented in the database data model.

Tags: Database

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