On Sun, 21 Mar 1999 08:13:46 -0000, Adam Powell wrote:
>Does this look as optimised as it can get or am I doing something wrong, as
>its causing the server load to be extraordinarily high.
1. if you don't need it indexed, don't index it. Creating the index
entry takes a lot of resources.
2. Pack the data. You need only 4 bytes for the IP address. Use a
32-bit int, and convert a.b.c.d to entry = (((a << 8) + b) << 8 + c) <<
8 + d. To decode, do:
d = entry & 0ffx; entry = entry >> 8;
c = entry & 0ffx; entry = entry >> 8;
b = entry & 0ffx; entry = entry >> 8;
a = entry & 0ffx;
Or something like that.
You now use 4 bytes rather than 16. Both data and index get much
smaller, and comparisons are much simpler (no prefix compression,
case-sensitivity, sort order).
3. Make your buffers such that the entire table or at least index fits
in memory. Obviously, also much easier with 4 bytes than with 16.
4. If you put the IP string in as is, you may get difficulties, i.e.
001.001.001.001 = 188.8.131.52 etc.
(Frederik Lindberg, Infectious Diseases, WashU, St. Louis, MO, USA)
|• performance||Adam Powell||21 Mar|
|• Re: performance||Fred Lindberg||21 Mar|