Support Trace Flag 834 with Columnstore
Trace flag 834 has been marked as unsupported with columnstore by Microsoft since SQL Server 2012, but that trace flag resolves columnstore and batch mode related bottlenecks with the RESERVEDMEMORYALLOCATION_EXT wait when running workloads at high concurrency. In addition, vendors use TF 834 with columnstore when competing in the TPC-H benchmarks.
Please support TF 834 with columnstore.
References with reproducible workloads:
Joe Obbish commented
Leaving this as a comment because I can't figure out how to edit these. Another reproduction can be found here: https://orderbyselectnull.com/2018/03/13/the-return-of-reserved_memory_allocation_ext/