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Do you have any formal or informal standards for reasonably achievable SQL query speed? How do you enforce them? Assume a production OLTP database under full realistic production load of a couple dozen queries per second, properly equipped and configured...
Started by le dorfier on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
Transactional and search queries can't be moved off transactional system, so and anything worse like N^2 will eventually ....
95% of search queries (more within 10 seconds.
Of this might be:
95% of transactions to complete within 2 seconds .
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Hey, I'm doing a website that requires me to use about 5 mysql "SELECT * FROM" queries on each site and I'd like to know if it can slow the download speed in any way.
Started by Mike on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
The big question is: how much ....
If you have queries that take a long time to send to the client (where the queries happen), the download speed will depend on how big the content in #2.
Especially if the tables contain lots or rows.
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I am using System.Management namespace in a .Net to execute various WMI queries against a remote server. In my logs I can see that sometimes the queries take 30 or 40 seconds to complete while other times the queries complete in less than a second.
When...
Started by Josh Clark on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
I also find some queries on the same machine behave differently then other queries on the same ....
Using wbemtest is sometimes faster but not necessarily.
queries on all different kinds of devices and I experience the same behavior.
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When I optimize my 2 single queries to run in less than 0.02 seconds and then UNION them the resulting query takes over 1 second to run. Also, a UNION ALL takes longer than a UNION DISTINCT. I would assume allowing duplicates would make the query run ...
Started by Greg on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
Do your queries include ORDER queries separately? I would ....
When I optimize my 2 single queries to run in less than 0.02 seconds and then UNION them the resulting query takes over 1 second to run.
Test this here right now.
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My database queries from Django are starting to take 1-2 seconds and I'm having trouble figuring out why. Not too big a site, about 1-2 requests per second (that hit Django; static files are just served from nginx.)
The thing that confuses me is, I can...
Started by lacker on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at serverfault):
It will show you the queries you're making on each page load.
Do you use custom SQL queries with Django or have you fetched/robhudson/django-debug-toolbar).
You mean with "exact queries".
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There's ways to get performance graphs with several monitoring software packages out there such as ZenOSS. There's a plugin available that will graph MySQL based SELECT/WRITE/SLOW queries in a nice rrd style graph.
I'm curious if there is a way to also...
Started by imaginative on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at serverfault):
I use PNP as a quick-and-dirty means of....
You'll still need to use something like perfmon if you want to graph it .
It might suite your needs.
Have a look at http://www.monitoringexchange.org/inventory/Check-Plugins/Database/MySQL/check%5Fmysql%5Fperf.
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I have some queries that are causing timeouts in our live environment. (>30 seconds)
If I run profiler and grab the exact SQL being run and run it from Management Studio then they take a long time to run the first time and then drop to a few hundred...
Started by Robin Day on
, 7 posts
by 7 people.
Answer Snippets (Read the full thread at stackoverflow):
Hi,
May I suggest that you inspect the....
From MSDN:
"Use DBCC DROPCLEANBUFFERS to test queries with a cold buffer cache without use this in your development environment whilst tuning the queries for deployment to a live server.
Strategy.
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Somewhat strange problem... when I start my .NET app for the first time after rebooting my machine, the SQL Server queries are really slow... when I pause the debugger, I notice that it's hanging on getting the response from the query. This only happens...
Started by JoelFan on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
If you run the query....
When you first run a query, SQL generates an execution plan and then caches it.
Most likely you are enjoying the caching affect.
Perhaps TCP/IP is not first in the list.
Check your SQL Server Client Config Settings...
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Recently (in the last few days), my installation of IE8 has been taking 15 to 20 seconds to load my home page. Specifically, the sequence of events (as reported by WireShark) is:-
Browser issues a DNS A query to resolve the home page server's IP address...
Started by MikeJ-UK on
, 7 posts
by 7 people.
Answer Snippets (Read the full thread at serverfault):
Is your computer a domain member, or was it ever?
Those LDAP queries looks a lot like what happens or if it's another process issuing the DNS LDAP queries?
Why does it receive no answer? It's a DNS Query, the lack, maybe 8 queries....
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We've recently started using complied queries in order to improve performance on our Linq to SQL setup. There are several queries that always take multiple seconds to run the first time take under a second in subsequent runs. This appears to be because...
Started by Mykroft on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
The database will be caching 2 things when the SQL is executed:
execution plan data The execution plan will remain in the cache... .
The server need to be the query plan on the first execuation, it then uses the cached plan for subsequent executions.
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