In a previous blog post, we've advertised the use of SQL EXISTS rather than COUNT(*) to check for existence of a value in SQL. I.e. to check if in the Sakila database, actors called WAHLBERG have played in any films, instead of: SELECT count(*) FROM actor a JOIN film_actor fa USING (actor_id) WHERE a.last_name = … Continue reading An Efficient Way to Check for Existence of Multiple Values in SQL →
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In my previous post, I spoke of "Normalized" and
"Non-Normalized" CPU utilization values:
--
TABLE:Foreword: Windows is not "process" based OS (like Linux)
but rather "thread" based so all of the numbers relating to CPU
usage are approximations. I did made a "proper" CPU per Process
looping and summing up Threads counter
(https://msdn.microsoft.com/en-us/library/aa394279%28v=vs.85%29.aspx)
based on PID but that proved too slow given I have ~1 sec to deal
with everything. CPU utilization using RAW counters with 1s delay
between samples proved to produce a bit more reliable result than
just reading Formatted counters but, again, too slow for my 1s
ticks (collect sample, wait 1s, collect sample, do the math takes
longer than 1s). Thus I use PerfFormatted counters in version
0.9RC.
[Read more]
Win32_PerfRawData_PerfProc_Process; …
Welcome to the final blog in Windows PerfCounters and Powershell
series and sorry for the delay. The purpose of this blog is to
explain the inner workings of top-script.ps1 script and practical
usage of Performance counters on Windows through Powershell. It
is intended for people who want Linux top - like tool on
Windows.
The script is a part of and available in our existing benchmarking package (dbt2-0.37.50.10) developed
by Mikael Ronstrom.
On Top:If you ever did benchmarking on Linux or simply wondered
"where did all my resources go", top is your best friend. Since
this post is not about Linux, you can google "Linux top
explained" for more details.
On Performance counters:To learn about Windows PerfCounters,
please refer to my previous …
This is the 182nd edition of Log Buffer, the weekly review of database blogs. Make sure to read the whole edition so you do not miss where to submit your SQL limerick!
This week started out with me posting about International Women’s Day, and has me personally attending Confoo (Montreal) which is an excellent conference I hope to return to next year. I learned a lot from confoo, especially the blending nosql and sql session I attended.
This week was also the Hotsos Symposium. …
[Read more]
In my last blog post, I showed how we can get some raw
performance information from /proc into the MySQL database using
a LOAD DATA INFILE (LDI) command.
I've modified that LDI call slightly to set the `other` column to
equal the sum total of the CPU counters for those rows which
begin with 'cpu'.
original:
other = IF(@the_key like 'cpu%', NULL , @val1);
new:
other = IF(@the_key like 'cpu%', user + nice + system + idle +
iowait + irq + softirq + steal + guest, @val1);
Top provides a useful output that looks something like the
following:
top - 04:59:14 up 14 days, 3:34, 1 user, load average: 0.00, 0.00, 0.00 Tasks: 216 total, 1 running, 215 sleeping, 0 stopped, 0 zombie Cpu(s): 0.0%us, 0.0%sy, 0.0%ni, 99.9%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 8172108k total, 5115388k used, 3056720k free, 315180k buffers Swap: 2097144k total, 0k …[Read more]
Apr
28
2008
Inspired by the Rail Spikes:
bash-3.2$ history 1000 | awk '{a[$2]++}END{for(i in a){print a[i]
" " i}}' | sort -rn | head
228 cd
167 git
10 ssh
10 DEPLOY=production
6 sudo
6 pwd
6 ./script/import_views.rb
5 rm
4 rake
4 mv
bash-3.2$
Really interesting stats, I’d never guess that git is used more than ssh on my desktop (I’m a remote worker and mysql consultant so I ssh really often).