Slow or non-operational Query Store under legacy cardinality estimator
In many of our customers environment Query Store is completely non-operational or very slow. No report of Top Resource Consuming Queries is generated in timely fashion, no matter what configuration options is set. Other reports with some background data behave the same. So the tool is practically useless.
If I try any SELECT statement that is generated by Query Store run in standalone SSMS windows, result is the same - did not finish.
I found out it's because our databases are in legacy cardinality estimation mode. When I run appropriate SELECT with OPTION (QUERYTRACEON 2312) the result appear in acceptable time.
Would it be possible to force Query Store GUI queries being generated with this option?