Why does SQL server estimate 10k rows, reads 100K rows just to bring back 100 rows in the final result, especially in large queries? I've tried indexing, updating stats, tinkering with trace flags and forcing index use but to no avail. The said tables don't even have 100K rows.
I can’t reasonably answer that based on the question as stated. You may want to try asking on dba.stackexchange.com/ where you can provide sufficient detail.
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informative video, though i m not really intelligent enough in DB side to truly appreciate it.
Hey, stick around, we’ll get you there.
@@ErikDarlingData hahah sure why not
You mention something at 8:23. I want to confirm does it really truncate the spool every time it asks for data from the maim tables
Yes, that is true for lazy table spools.
Why does SQL server estimate 10k rows, reads 100K rows just to bring back 100 rows in the final result, especially in large queries? I've tried indexing, updating stats, tinkering with trace flags and forcing index use but to no avail. The said tables don't even have 100K rows.
I can’t reasonably answer that based on the question as stated. You may want to try asking on dba.stackexchange.com/ where you can provide sufficient detail.
So are ur videos majorly fovused on DB architect ?
They primarily focus on SQL Server performance tuning at various levels. I don't get into normal forms or ERDs etc.
Thx, but thats your first video where you lost me a bit. Maybe I need a refresher on those execution plans.
Well, that's what these videos are for.