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visits member for 2 years, 2 months
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7h
asked What are recommended (working) permissions for a user to view all SQL Agent jobs
Aug
18
comment Why is an additional filtered statistic being ignored (EAV schema)?
Hmm. If that were true, cases A, C, & D should have no effect but yet they do. Perhaps this is because of the "recompile" option which is mentioned in the cited link and clarified in the comments by Paul White. I will try and make some time to retest to be sure.
Aug
13
comment How can row estimates be improved in order to reduce chances of spills to tempdb
A link to some problematic issues with multi column statistics.
Aug
9
comment Why does Recursive CTE estimate just 1 row?
@ypercube well, it "does not enough math" is a kind of an answer. For instance why not see the top "N" and use "N" as the estimate? A 1 row estimate does not seem probable for any CTE. Since plans may don't change until some cost threshold is crossed maybe they chose 1 since it has same effect as 50 which might be just as bad a guess for a fixed CTE, etc. Along those lines... Is someone certain that anything not based on row statistics will always estimate 1?
Aug
8
comment Why does Recursive CTE estimate just 1 row?
The example is just there to demonstrate the problem. I assume this happens for more general CTE's sometimes (I can't come up with a case right now though). Does no one care that the estimate for a cross of 100 x 100 is 1? The question says "...while keeping the CTE approach." Just answering "Why" for this specific case would be acceptable and help unravel some mystery.
Aug
8
asked Why does Recursive CTE estimate just 1 row?
Jul
25
comment Is support for Parallel Scalar UDF a reasonable feature request?
Clarifying comment. Success with ITVF but not multi-statement TVF.
Jul
24
comment Is support for Parallel Scalar UDF a reasonable feature request?
Sorry, forgot "scalar" in original question, glad you inferred correctly.
Jul
24
accepted Is support for Parallel Scalar UDF a reasonable feature request?
Jul
24
revised Is support for Parallel Scalar UDF a reasonable feature request?
UDF -> Scalar UDF
Jul
24
comment Is support for Parallel Scalar UDF a reasonable feature request?
Yes on success with TVF workaround. I asked because it seems wrong to avoid using such a natural construct. Also it seems impractical to expect new SQL developers to learn UDF internals.
Jul
24
asked Is support for Parallel Scalar UDF a reasonable feature request?
Jul
24
accepted Is is possible to handle a UserAbort or ClientTimeOut within a Stored Procedure?
Jul
23
answered Why does ORDER BY not belong in a View?
Jul
23
revised Is is possible to handle a UserAbort or ClientTimeOut within a Stored Procedure?
code comment fix
Jul
23
asked Is is possible to handle a UserAbort or ClientTimeOut within a Stored Procedure?
Jul
2
awarded  Curious
Jul
1
awarded  Yearling
Jun
3
comment Which SQL Server system database is more important: master or resource?
@user8365: The sub questions seem okay but the abstract headline is probably why it was closed.
May
23
comment Why are queries causing spill to tempdb?
Slightly tangent point but I'm sitting in front of a 10 table join that by default mostly uses merge joins with very good row estimates that causes tempdb level 0 spills and runtime 25s. Forcing hash joins (and order) removes the spills and runs in 9s. I'm left wondering whether its the merge vs hash or the spill causing difference and whether the optimizer is properly weighting the effect of a seemingly known upcoming spill (because row estimates are very good).