All Questions
Tagged with t-sql query-performance
78 questions
1
vote
2
answers
62
views
Sql Server: Query to parse and validate codes
We have a #ValidCode table with list of valid codes like: 'A', 'B', 'C', etc. Another table called #SourceData with input data -- that comes as a combination of valid and invalid tokens (sometimes ...
- 717
0
votes
2
answers
87
views
How to simplify this intersect query?
SELECT * from M
left JOIN K on M.id = k.id
left JOIN W on K.str = W.str where str = N'أخبار'
INTERSECT
SELECT * from M
left JOIN K on m.id = k.id
left JOIN W on K.str = W.str where str = N'فلسطين'
...
- 99
0
votes
0
answers
53
views
Azure SQL Database :: table size query takes forever to execute
I was working with the awesome Azure SQL Database Diagnostic Information Queries created by Glenn Berry and I realized that the query number 40 takes forever to execute:
-- Get Schema names, Table ...
- 1,685
-4
votes
2
answers
706
views
Calculate total_worker_time in minutes [closed]
I have an easy query which can show me the top 10 elapsed time by query_plan_hash and query_hash:
PRINT '-- top 10 elapsed time by query_plan_hash and query_hash --'
SELECT TOP 10 query_plan_hash
...
- 1,685
0
votes
1
answer
2k
views
Does a select within a where clause affect performance?
I know that we should avoid using functions in the where clause of a query wherever possible since the function will run for every row to return the proper results. However, does the same principle ...
- 155
-1
votes
1
answer
360
views
How to enhance performance when compare two table feature value to run faster?
I work on sql server 2019 i face issue when compare feature values between two tables
Based on RecomendationId .
it take too long time to display result
time that take it 5 minute .
total rows on ...
- 101
1
vote
1
answer
3k
views
Query optimisation to remove nested loop
I have below query which is having high Sub-tree cost. I have created appropriate Indexes for for the query which are getting seek but, still the sub-tree cost in high.
however, I can see nested Loop (...
- 33
0
votes
1
answer
49
views
Inhibiting results to pane in SSMS (TSQL language) via script
I found that one could use a menu to "discard" results in SSMS (TSQL language). Please see: Original Question about inhibiting results and its answer.
However, I was wondering if there is a ...
- 207
8
votes
3
answers
3k
views
Improper use of logical operators has led to poor query performance
I have a table with huge amount of data (Nearly 15 million) and below structure.
create table test
(a int,--> /* There is a normal index on this column */
b int,
<other columns>)
There is a ...
- 1,510
3
votes
3
answers
2k
views
Reducing Temp Table Scans when joining two temp tables using OR conditions
I'm working on a complicated query. I have up to this point been able to refactor to reduce execution time as well as number of scans and reads. At this point in the query, we have two temp tables ...
- 115
1
vote
1
answer
3k
views
Query to divide each column value to two categories: [Common , Not_Common]
I have a table with below structure and data:
create table PTEST
(
col_name VARCHAR(50),
col_value VARCHAR(50)
)
COL_NAME COL_VALUE
-----------------------
first apple
...
- 1,510
2
votes
1
answer
346
views
Forwarding records in #temp table
I have a temp table which I update many times based on joins (each time almost all the rows). I have kept it as a heap since if I don't get an inner loop join then after each update I get a sort in ...
- 817
2
votes
3
answers
279
views
Query to update one column of a table based on a column of a different table
I have two tables with below structure :
Create table Customer_info
(Customer_num varchar(50),
Customer_Branch int);
Create table Customer_Transaction_Info
(Customer_num varchar(50),
...
- 1,510
0
votes
1
answer
32
views
Query specific key fields from x-number of tables?
I'm building an insurance database and I need some help with best practice on fast quering data.
Let's say I have three insurance types ... Car, Home and Travel.
Common for all three types, I have the ...
- 101
3
votes
1
answer
655
views
Query optimization issue on view with RANK on DateTime for most recent rows
I'm having a problem with a view, that is designed to store sync data, for an iOS app, that syncs data back and forth to a web service. The XML fields are used to store both structured data for ...
- 299