To start I have a table that has ticketholders. Each ticket holder has a unique number and each ticket holder is associated to a so called household number. You can have multiple guests w/i a household.
I would like to create 3 flags (form a, for a household that has 1-4 gst) form b 5-8 gsts... (3 Replies)
Hi,
this might be a basic question...
why is that wc -c counts 1 more per line than what is there.
for example,
> cat dum1.txt
123
12
> wc -c dum1.txt
7 dum1.txt
Thanks,
Sameer. (4 Replies)
Hi,
I have a file with 2500 entries. There are many duplicates,triplicates symbols in my file in the first column and the second column has categories(high/medium/low) . I want to have count for the occurances of each category for each unique symbol
ABC high
ABC high
ABC medium
ABC ... (2 Replies)
This is very easy , but I`m struggling .. please help modify my script,
I want to count the number of h and n , from the second column group by the first. The second column is binary, can only have h and n.
a h
a h
a n
a n
a h
b h
b h
b h
b h
b h
c n
c h
c h
c h
c h (2 Replies)
In the attached file if I do a count for "aaaaaaaaaaaa" in either notepad++ or excel I get 118,456.
However, when I do either
grep -o aaaaaaaaaaaa 12A.txt | wc -w or
awk '{
for (i=1;i<=NF;i++)
if ( $i == "aaaaaaaaaaaa")
c++
}
END{
print c}' 12A.txt
I... (3 Replies)
Hi,
Recently i have write a simple script to capture CPU high usage based on prstat but i found out that it did capture correctly. I need to capture the rows that contains CPU usage more than 3%. Below line which i thought will capture CPU usage based CPU column in prstat(9th parameter) which is... (3 Replies)
Discussion started by: tharmendran
3 Replies
LEARN ABOUT DEBIAN
bup-margin
bup-margin(1) General Commands Manual bup-margin(1)NAME
bup-margin - figure out your deduplication safety margin
SYNOPSIS
bup margin [options...]
DESCRIPTION
bup margin iterates through all objects in your bup repository, calculating the largest number of prefix bits shared between any two
entries. This number, n, identifies the longest subset of SHA-1 you could use and still encounter a collision between your object ids.
For example, one system that was tested had a collection of 11 million objects (70 GB), and bup margin returned 45. That means a 46-bit
hash would be sufficient to avoid all collisions among that set of objects; each object in that repository could be uniquely identified by
its first 46 bits.
The number of bits needed seems to increase by about 1 or 2 for every doubling of the number of objects. Since SHA-1 hashes have 160 bits,
that leaves 115 bits of margin. Of course, because SHA-1 hashes are essentially random, it's theoretically possible to use many more bits
with far fewer objects.
If you're paranoid about the possibility of SHA-1 collisions, you can monitor your repository by running bup margin occasionally to see if
you're getting dangerously close to 160 bits.
OPTIONS --predict
Guess the offset into each index file where a particular object will appear, and report the maximum deviation of the correct answer
from the guess. This is potentially useful for tuning an interpolation search algorithm.
--ignore-midx
don't use .midx files, use only .idx files. This is only really useful when used with --predict.
EXAMPLE
$ bup margin
Reading indexes: 100.00% (1612581/1612581), done.
40
40 matching prefix bits
1.94 bits per doubling
120 bits (61.86 doublings) remaining
4.19338e+18 times larger is possible
Everyone on earth could have 625878182 data sets
like yours, all in one repository, and we would
expect 1 object collision.
$ bup margin --predict
PackIdxList: using 1 index.
Reading indexes: 100.00% (1612581/1612581), done.
915 of 1612581 (0.057%)
SEE ALSO bup-midx(1), bup-save(1)BUP
Part of the bup(1) suite.
AUTHORS
Avery Pennarun <apenwarr@gmail.com>.
Bup unknown-bup-margin(1)