From: | Mark Kirkwood <markir(at)paradise(dot)net(dot)nz> |
---|---|
To: | Martijn van Oosterhout <kleptog(at)svana(dot)org> |
Cc: | Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>, Mike Castle <dalgoda(at)ix(dot)netcom(dot)com>, pgsql-general(at)postgresql(dot)org |
Subject: | Re: qsort (was Re: Solaris) |
Date: | 2003-05-01 22:52:11 |
Message-ID: | 3EB1A51B.3070806@paradise.net.nz |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
Martijn van Oosterhout wrote:
> Anyway, on a Debian Woody machine here I get:
>
>10^6 items, mod = 100
>
>Value (i = index) BSD GLIBC (seconds)
>random() * mod 1.58 2.29
>i % mod 0.52 1.69
>i / (ITEMS / mod) 0.38 1.09
>i ^ 0x5555555 1.18 1.67
>
>It would seem to support the theory that the BSD qsort is faster than the
>Glibc one. The results seem quite repeatable (repeats give +/- 5%).
>
Martin's test on two Linux machines here gives :
10^6 items, mod = 100
1) Mandrake 9 (x86 - Linux 2.4.19, glibc 2.2.5, gcc 3.2)
Value (i = index) BSD GLIBC (seconds)
random() * mod 2.20 2.70
i % mod 0.80 2.10
i / (ITEMS / mod) 0.53 1.28
i ^ 0x5555555 1.64 1.95
2) Yellowdog 2.3 (ppc - Linux 2.4.19, glibc 2.2.5. gcc 2.95.4)
Value (i = index) BSD GLIBC (seconds)
random() * mod 1.74 3.12
i % mod 0.69 2.65
i / (ITEMS / mod) 0.55 1.66
i ^ 0x5555555 1.42 2.45
Interestingly, the the ppc machine gets more improvement from the BSD
qsort than the x86 one does.
regards
Mark
From | Date | Subject | |
---|---|---|---|
Next Message | scott.marlowe | 2003-05-01 23:02:14 | Re: Do I need a special version of Postgresql to run on |
Previous Message | Hadley Willan | 2003-05-01 22:48:24 | Do I need a special version of Postgresql to run on RH Linux Enterpise Standard? |