All Questions
4 questions
1
vote
2
answers
90
views
Is there a "correct" way for an optimizer to process a subquery if the outer query has additional where filters?
This topic came up for me as the result of investigating an error in Redshift. We have a table containing a column of numbers represented as text, but for rows where no value is present a single ...
- 111
2
votes
0
answers
628
views
Correlated subquery with common table expressions in SQLite
Yesterday I achieved a 500x performance boost after rewriting an EXISTS with IN. I did some investigation to find out why and finally came to the following example. Basically, we draw 5 lucky numbers ...
- 131
2
votes
0
answers
94
views
Is it possible to replace count distinct inside Correlated sub-queries?
I'm trying to optimize the query bellow. The execution Plan is showing multiple sorting before aggregations (I think this is due to the count distincts in the correlated sub-queries)...
Is it ...
- 21
4
votes
2
answers
18k
views
conditional subquery
I have the following query:
SELECT id,
email,
first_name as "firstName",
last_name as "lastName",
is_active as "isActive",
password,
access,
CASE
WHEN access < 3 THEN (
...
