0
votes
1answer
45 views

Does it make sense to order condition in where query?

We have a clustered index in table Tbl with order of A,B,C. Does it make senses to write a query to have WHERE A = @a, B = @b, C = @c or it'll be as same as WHERE C = @c, B = @b, A = @a Does the ...
0
votes
1answer
81 views

How to deal with async calls to a stored procedure that updates data

I have asynchronous calls from Entity Framework to a stored procedure. The stored procedure selects data to a temp table and later on, it updates the real table. This works fine for sync calls. The ...
0
votes
1answer
49 views

Is a single batch request equivalent to a single tsql request?

I'm looking into some performance metrics and every recommendation includes monitoring Batch Requests/sec. But, maybe a silly question, does a singe batch request correspond to exactly one tsql ...
0
votes
4answers
97 views

SQL Where Clause Efficiency

Say I have a SQL statement: SELECT * FROM MyTable WHERE KeyColumn1 = 1 OR KeyColumn1 = 2 OR KeyColumn1 =3 OR ... KeyColumn1 = 10 And another: SELECT * FROM MyTable ...
0
votes
4answers
100 views

T-SQL: Complete Database in one table

at a relational data model every logical relation is a single table with values and so on. I know someone who is this too much work and he wants to create only one table which contains all. This could ...
3
votes
1answer
134 views

Frequent Delete & Insert, impact on performance

In my application, we have very few updates. Most of the data gets deleted and inserted. My question is, how this will impact the performance? We are using SQL Server 2012. Table statistics (will ...
11
votes
1answer
1k views

GO After every T-SQL statement

What is the reasoning behind using the GO statement after every SQL statement? I understand that GO signals the end of batch and/or allows the reputation of statements but what advantage does it have ...
2
votes
1answer
94 views

Avoiding Deadlocks

We currently have a trigger-based system in place that does the following: When records in certain tables are modified, a trigger fires that makes a field NULL in a varying number of records in ...
2
votes
1answer
251 views

Performance issue with TOP (1) on a nullable column

I need help to identify the reason for a performance issue. Actually following query sits in a scalar-valued-function but that is not the reason for the issue since it needs the same time as query: ...
0
votes
1answer
608 views

LEFT vs CHARINDEX for matching the start of a string in T-SQL

I want to match the beginning of a string in a WHERE clause. While I recognise that so often database-performance is dependant on the underlying data structure, is there a best-practice for doing ...
0
votes
0answers
280 views

How to improve the performance for SQL Server Count(distinct()) and Sum() functions? [closed]

The below one is my query. It's taking 12 seconds for the execution process. The count(distinct()) and SUM() functions are taking long time for execution. I tried it after create the non-cluster index ...
-7
votes
2answers
553 views

How can I check for SQL Server performance problems using T-SQL? [closed]

I know how to use the Profiler, Performance Monitor, and Activity Monitor. I want to find a way to troubleshoot performance using T-SQL. How can I check for Microsoft SQL Server performance problems ...
2
votes
1answer
3k views

exist (select * from my table)

My colleague suggests that Query 1 should run faster than Query 2. If it's true, please anyone explain me the reason. Thanks. Query (1): IF ( SELECT COUNT(UnitTrustCounterId) FROM ...
1
vote
1answer
338 views

Using sys.dm_os_performance_counters and DIFF to display logins per second

PROBLEM Running my script below i can see the number of logins as an accumulated number to my instance: SELECT cntr_value AS [LoginsPerSec] FROM sys.dm_os_performance_counters WHERE ...
1
vote
1answer
296 views

What can cause an UPDATE statement to execute endless? [closed]

I have a stored-procedure which is executed at 7 o'clock in the morning that updates the database because new records were imported at night. Today it started but never endet. So i've tried to run ...
5
votes
2answers
1k views

The order of INNER JOIN's

I would like to know if there are any rules about the order of INNER JOIN's in T-SQL 2000. I had 62x the performance on my query when my INNER JOIN that act like a filter is placed at first instead ...
2
votes
2answers
1k views

Solving high page load time using SQL Profiler

I'm looking into a performance of a login page taking 10-13 seconds to load. I'm using a DEMO database to test the performance and tweak to see any improvement. I'm using SQL Profiler to capture what ...