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  3. September 2020

Re: help with SQL performance when using ORDER BY

So you want 100 random rows from the results, and then to sort them? That
doesn't sound like a common requirement.

Would this work?
with CTE as (
select *
from TABLE_NAME
fetch first 100 rows only
)
select *
from CTE
order by COL1


date: Thu, 24 Sep 2020 06:09:24 -0400
from: Mark Villa <iseries.4.me@xxxxxxxxx>
subject: help with SQL performance when using ORDER BY

Hi all,
I have been doing a lot of "SQL checking" recently and without breaking out
the manuals, I am just curious what you guys do when you use ORDER BY. With
tables greater than 10 or 20 mil rows it really tanks. Otherwise, my
responses are usually subsecond.

It makes the SQL engine (and myself) look dumb when I can't say
"select these 100 rows" then ORDER THEM, don't look at 20 million rows,
don't need anything sorted but the final set.

--
Thank You,
Mark Villa




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