5
votes
Accepted
Is my query having Parameter Sniffing performance issue
nope
You don't have a parameter sniffing problem because you don't have any parameters. You are using local variables, which means you'll always get the same density vector estimate no matter which ...
4
votes
Accepted
Will the query time increase?
Think of a telephone book.
Does it take longer to search for a name if a telephone book for a larger city, with thousands or millions of people?
Yes, of course it does.
But doubling the number of ...
- 16k
3
votes
How do I tell Postgres to only scan the newest values in this query?
It's the classic "Top-N by category" problem, with a bit of a plot twist.
Fastest solution will probably be a lateral join. This allows executing a join with a dependent subquery.
If you ...
- 1,691
1
vote
Will the query time increase?
Will it increase? Almost certainly.
By how much? As with all things, it depends.
If you are finding rows by a single values on a uniquely-indexed field, the query can use an index (possibly the ne ...
- 9,480
1
vote
transactions without a corresponding session in sql server
My guess is that they belong to internal sessions used by SQL Server engine. I have an instance on my desktop, which I just started in order to check that, and after executing that same query the ...
- 5,926
1
vote
Is my query having Parameter Sniffing performance issue
ymmv
A further option/improvement to @ErikDarling's answer is to use window functions instead of those CROSS APPLYs.
DECLARE
@orgId integer = 22,
@salesperson integer = 0,
@sql nvarchar(...
- 14.5k
1
vote
Accepted
Sql Server: Query to parse and validate codes
One relational way you can do this is by splitting your #SourceData first (fortunately you have access to the STRING_SPLIT() function despite being on an outdated version of SQL Server), then getting ...
- 39.5k
1
vote
Sql Server: Query to parse and validate codes
-- first thing that comes to mind:
SELECT
sd.ID
, sd.Codes
, CASE
WHEN NOT EXISTS (
SELECT x.[value]
FROM string_split(sd.Codes, ';') as x
...
- 49
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