A table scan is quite often performed if more than 15-20% of the rows of a
table is returned (and there is no appropriate EVI).
<> and OR let expect that more than 15-20% of the rows are returned
Mit freundlichen Grüßen / Best regards
Birgitta Hauser
"Shoot for the moon, even if you miss, you'll land among the stars." (Les
Brown)
"If you think education is expensive, try ignorance." (Derek Bok)
"What is worse than training your staff and losing them? Not training them
and keeping them!"
?Train people well enough so they can leave, treat them well enough so they
don't want to.? (Richard Branson)
-----Original Message-----
From: MIDRANGE-L <midrange-l-bounces@xxxxxxxxxxxxxxxxxx> On Behalf Of Justin
Taylor
Sent: Mittwoch, 8. Januar 2020 17:26
To: MIDRANGE-L (midrange-l@xxxxxxxxxxxxxxxxxx)
<midrange-l@xxxxxxxxxxxxxxxxxx>
Subject: Why Table Scan?
I'm troubleshooting performance of a query. VE is showing a Table Scan, and
I don't know why it's doing a Table Scan. It's on joining two views. The
JOIN ON is just <> or = conditions. The Optimized Messages tab shows "Debug
messages are not available".
Any suggestions on this?
Thanks
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