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From:Dan Nelson Date:October 5 2001 7:28pm
Subject:Re: Bizarre query performance
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In the last episode (Oct 05), Philip Brown said:
> Server: SCO OpenServer V3.2 R5.0.5, AMD K6-2 350Mhz CPU, 128Mb RAM
> mySQL: 3.23.39, compiled by me to avoid use of libraries, using latest
> available pthreads
> 
> Clients: Win32 machines (more detail later).
> 
> There are 2 times I am interested in, the time to execute a query, and the
> time required to fetch the results across the network (100Mbps LAN, 3
> isolated workstations in test setup).
> 
> Basically I have been timing the mysql_query() and the mysql_store_result()
> calls on the client. I have been getting some very bizarre results, that are
> 100% reproducible:

I suppose your test program connects, and loops the same query multiple
times in the same session?  (Just to rule out connect/disconnect
overhead)

What are your timings if you run your client on the SCO box?  If all
your queries are instantaneous, I'd say start dumping packets on the
network.  200ms sounds a lot like Nagle's Algorithm kicking in (which
shouldn't happen assuming the mysql libs are written right).  

-- 
	Dan Nelson
	dnelson@stripped
Thread
Bizarre query performancePhilip Brown5 Oct
  • Re: Bizarre query performanceRussell Miller5 Oct
    • RE: Bizarre query performancePhilip Brown5 Oct
      • Re: Bizarre query performanceRussell Miller5 Oct
        • RE: Bizarre query performancePhilip Brown5 Oct
          • Re: Bizarre query performanceRussell Miller6 Oct
            • RE: Bizarre query performancePhilip Brown6 Oct
  • Re: Bizarre query performanceBoyd Lynn Gerber5 Oct
    • RE: Bizarre query performancePhilip Brown5 Oct
      • RE: Bizarre query performanceBoyd Lynn Gerber5 Oct
  • Re: Bizarre query performanceDan Nelson5 Oct
    • RE: Bizarre query performancePhilip Brown5 Oct
      • Re: Bizarre query performanceDan Nelson5 Oct
        • Re: Bizarre query performanceBoyd Lynn Gerber6 Oct
          • RE: Bizarre query performancePhilip Brown6 Oct
            • Re: Bizarre query performanceDan Nelson7 Oct
              • Preventing Nagle with mysql (was: Bizarre query performance)Philip Brown8 Oct
                • Re: Preventing Nagle with mysql (was: Bizarre query performance)Dan Nelson10 Oct
                  • Re: Preventing Nagle with mysql (was: Bizarre query performance)Sinisa Milivojevic10 Oct