All Questions
Tagged with database-tuning query-performance
8 questions
0
votes
1
answer
206
views
Different performance of SQL Server instances on same server
I have 4 development SQL Server 2016 instances on a virtual server (128 GB, 12 virtual processors). Each instance is configured the same (16 GB memory, automatic processor and I/O affinity masks). ...
- 63
0
votes
1
answer
76
views
What dataset(s) is Marcus Winand using in his book "SQL Performance Explained"?
I am currently reading SQL Perfrmance Explained by Marcus Winand. I would like to follow along with the queries and examples he used to explain database tuning. It would greatly allow me to understand ...
- 103
13
votes
2
answers
2k
views
SELECT TOP 1 harms query performance; is there a dba-accessible way to overcome this?
In a production application (C# talking to SQL Server 2014 Standard) there's a query that looks like this, below. Most of the time it runs in milliseconds. But occasionally (for certain values of @Id),...
- 583
0
votes
1
answer
862
views
What happens when the buffer pool size is insufficient in mysql
Let us assume I run a query for a table whose size is very huge. My buffer pool size is as low as possible. What happens now? whether I will get an error regarding the insufficient space in buffer ...
- 45
1
vote
0
answers
108
views
Tuning MySQL MyISAM for large joined updates
I have a database with two tables that I would consider small. I need to update values on the larger of the two tables (1,100,000 rows, 75M MYD, 120M MYI) from the join of the two tables. The smaller ...
- 131
4
votes
2
answers
697
views
Tuning Mysql and Monitoring
I would like to know if anybody can point me towards a tool/way for MySQL database tuning.
Actually the tuning of my.cnf is like below:
My database engine is MyISAM | Mysql 5.1.73
key_buffer = 500M
...
4
votes
1
answer
1k
views
Need help with long running query
UPDATE: Adding a clustered index to each work table covering all fields reduced the query run times to su-bsecond. I consider this question closed.
Thanks for taking the time to read this post - it'...
- 387
2
votes
1
answer
256
views
Slow Query Gets Even Slower After Indexing
I have a MySQL database with just one table containing 8 million records. I need to query the table to find a single record that matches a specific number:
select * from my_table
where
(...
- 21