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Date:	Tue, 29 Jul 2003 09:50:27 PDT7
From:	"Steven Levine" <steve53@earthlink.net >
Reply-To:	scoug-help@scoug.com
To:	scoug-help@scoug.com
Subject:	SCOUG-Help: utility to convert records to lines ?

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In <3F269986.6EBA@peterskye.com>, on 07/29/03
at 08:57 AM, Peter Skye said:

>Yes, this was done on purpose. The code to write the records to an
>output file would be identical in both cases, hence including it in the
>benchmark would be irrelevant.

The code would be identical, but the system I/O (i.e. head movement,
caching etc.) would be very different. It would only help the buffered
method.

>I can run the benchmark with additional file sizes and record sizes if
>you want more data.

Here's a version with cache flushing included:

iFileSize = 1000000
do while iFileSize <= 16000000
iRecSize = 10
do while iRecSize <= 100000
/* Flush cache */
x = charin( FillFile, , FillSize )
call stream FillFile, 'C', 'CLOSE'
x = ''
call stream TestFile, 'C', 'OPEN READ'
call Time( "R" )
do Index = 1 to iFileSize by iRecSize
x = charin( TestFile, , iRecSize )
end
ElapsedTimeByRecord = Time( "E" )
call stream TestFile, 'C', 'CLOSE'
/* Flush cache */
x = charin( FillFile, , FillSize )
call stream FillFile, 'C', 'CLOSE'
x = ''
/* Benchmark using CharIn() to read the entire file into a buffer.
*/
call stream TestFile, 'C', 'OPEN READ'
call Time( "R" )
buffer = charin( TestFile, , iFileSize )
do Index = 1 to iFileSize by iRecSize
x = substr( buffer, Index, iRecSize )
end
ElapsedTimeByBuffer = Time( "E" )
call stream TestFile, 'C', 'CLOSE'
say right(' ' iFileSize, 10),
right(' ' iRecSize, 12),
right(' ' ElapsedTimeByRecord, 18),
right(' 'ElapsedTimeByBuffer, 18)
iRecSize = iRecSize * 10
end /* iRecSize */
iFileSize = iFileSize * 2
end /* iFileSize */

And the results:
---- Seconds (uSec/Rec) to Read ---- Speed File
Size Record Size Individual Records Buffered Records Ratio ==========
=========== ================== ================ =====
1000000 10 10.620000 0.390000
1000000 100 1.090000 0.110000
1000000 1000 0.150000 0.080000
1000000 10000 0.050000 0.080000
1000000 100000 0.060000 0.080000
2000000 10 21.990000 1.330000
2000000 100 2.280000 0.250000
2000000 1000 0.300000 0.160000
2000000 10000 0.100000 0.140000
2000000 100000 0.090000 0.140000
4000000 10 44.410000 2.820000
4000000 100 4.880000 0.910000
4000000 1000 0.600000 0.300000
4000000 10000 0.200000 0.250000
4000000 100000 0.200000 0.260000
8000000 10 88.350000 5.420000
8000000 100 9.310000 1.010000
8000000 1000 1.200000 0.600000
8000000 10000 0.390000 0.560000
8000000 100000 0.380000 0.480000
16000000 10 175.920000 11.040000
16000000 100 18.420000 2.070000
16000000 1000 2.500000 1.170000
16000000 10000 0.790000 1.470000
16000000 100000 0.850000 1.000000

As expected, flushing the cache hurts the buffered version more than the
unbuffered version.

Steven

--
----------------------------------------------------------------------
"Steven Levine" MR2/ICE 2.37 #10183 Warp4/FP15/14.093c_W4
www.scoug.com irc.webbnet.info irc.fyrelizard.org #scoug (Wed 7pm PST)
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