Re: a heavy duty operation on an "unused" table kills my server - Mailing list pgsql-performance

From Eduardo Piombino
Subject Re: a heavy duty operation on an "unused" table kills my server
Date
Msg-id e24c1d9d1001131113x69d2f10anbee2c87dbd9856c4@mail.gmail.com
Whole thread Raw
In response to Re: a heavy duty operation on an "unused" table kills my server  (Greg Smith <greg@2ndquadrant.com>)
Responses Re: a heavy duty operation on an "unused" table kills my server
List pgsql-performance
Greg, I will post more detailed data as soon as I'm able to gather it.

I was trying out if the cancellation of the ALTER cmd worked ok, I might give the ALTER another try, and see how much CPU, RAM and IO usage gets involved. I will be doing this monitoring with the process explorer from sysinternals, but I don't know how I can make it to log the results. Do you know any tool that you have used that can help me generate this evidence? I will google a little as soon as possible.


On Wed, Jan 13, 2010 at 3:46 PM, Greg Smith <greg@2ndquadrant.com> wrote:
Robert Haas wrote:
I'm kind of surprised that there are disk I/O subsystems that are so
bad that a single thread doing non-stop I/O can take down the whole
server.  Is that normal?  Does it happen on non-Windows operating
systems?  What kind of hardware should I not buy to make sure this
doesn't happen to me?
 
You can kill any hardware on any OS with the right abusive client.  Create a wide table and insert a few million records into it with generate_series one day and watch what it does to queries trying to run in parallel with that.

I think the missing step here to nail down exactly what's happening on Eduardo's system is that he should open up some of the Windows system monitoring tools, look at both disk I/O and CPU usage, and then watch what changes when the troublesome ALTER TABLE shows up.


--
Greg Smith    2ndQuadrant   Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com  www.2ndQuadrant.com


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