Re: Nearest Common Ancestor Report (XDb1's $1000 Challenge)

From: Neo <neo55592_at_hotmail.com>
Date: 27 May 2004 16:04:30 -0700
Message-ID: <4b45d3ad.0405271504.43dbf2d_at_posting.google.com>


> I changed my model ... (SQL and output are down below).

Yes I see. The changes are a step in the right direction to make an equivalent comparison.

> The average execution time is 11.0 ms (as you can see from the output).
> This is based on an execution on my desktop system (1.3 GHz Athlon,
> 256 MB RAM, 2 harddisks at 40 GB / 7200 rpm each) with several open
> applications. XDb1 takes 16 ms for generating the report on the same
> machine with the same applications still active.

There seems to be some puzzling differences in our time measurements. We may need additional measurements from other users. Below are measurements made on my hardware.

Report Generation Time Summary
 (Apple-to-Orange Comparison)



  Implementation Avg
  • ------- RM Solution #2 68.9 ms XDb1 v4.5.3 3.4 ms

Details for the above summary follows:

Data Set: Small hierarchy of 8 things (as published on web page). Platform: Off-line, 500 Mhz, Dell PowerEdge, Dual Pentium, 512 MB,

          Ultra SCSC II, Dual 10K RPM HDs, NT 4 sp6a, 
          SQL Server 7 (default setup):
Method:   Restart PC, shut down all apps possible. 
          During RM runs, Query Analyzer and Notepad were active. 
          During XDb1 runs, Exe, Notepad and Explorer were active.

For RM:

Restart, Batch Run1: 690 msec for 10 conseq runs
Restart, Batch Run2: 690 msec for 10 conseq runs
Restart, Batch Run3: 687 msec for 10 conseq runs

For XDb1:
Restart

1  3.390952 msec
2  3.358835 msec
3  3.319436 msec
4  3.276699 msec
5  3.312431 msec
6  3.222425 msec
7  3.307787 msec
8  3.390360 msec
9  3.199336 msec
10 3.391635 msec

Restart

1  3.477234 msec
2  3.285603 msec
3  3.433378 msec
4  3.375522 msec
5  3.337268 msec
6  3.404299 msec
7  3.304393 msec
8  3.435634 msec
9  3.417309 msec
10 3.335882 msec

Restart

1  3.478627 msec
2  3.495449 msec
3  3.415239 msec
4  3.323602 msec
5  3.359083 msec
6  3.453251 msec
7  3.433410 msec
8  3.331556 msec
9  3.389169 msec
10 3.460645 msec

Notes:
1. XDb1 time measurements made via OS provided QueryPerformanceCounter() whose resolution is higher than TickCount and the resolution is dependent on PC's clock frequency (500 Mhz).

2. With other applications running, both solutions show intermittent spikes in execution time. For instance, some of XDb1's (v4.5.3) runs spiked as has as 19.4 ms and RM solution #1's runs spiked as high as 1186 ms.

3. IMO, it is still an apple-to-orange comparision because of differences in db/schema genericness and normalization. I will list these in another post. Received on Fri May 28 2004 - 01:04:30 CEST

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