Bad Performance of CDS View with Union

[jens_borau]

I have a ABAP CDS view in an ERP backend which uses a union with two selects.

Without the union one select takes about 4 seconds to load the data, the other select about 5 seconds.

With the union the loading takes about 1 Minute. I also tried using "union all", but performance did'nt change.

Does anyone has an idea how I could optimize the performance?

Why does it take so long, when the single selects just take some seconds to load?

[ugurozdemir]

Dear Jens,

We have exactly the same situation, have you found some notes or workarounds?

Any suggestion ? Regards

[matt]

What does the SQL trace show for each query alone and for the unionised ones?