Hi everyone,
This is my first post, but I have already received a lot of help from the forums in the past. Thanks!
I've searched the forums and my question is very similar to an earlier post entitled "Printing highest value from one column", which I am apparently not yet allowed to post a... (1 Reply)
Hi everyone,
This is my first post, but I have already received a lot of help from the forums in the past. Thanks!
I've searched the forums and my question is very similar to an earlier post entitled "Printing highest value from one column", which I am apparently not yet allowed to post a... (3 Replies)
Hello everyone,
I am writing a script to process data from the ATP world tour.
I have a file which contains:
t=540 y=2011 r=1 p=N409
t=540 y=2011 r=2 p=N409
t=540 y=2011 r=3 p=N409
t=540 y=2011 r=4 p=N409
t=520 y=2011 r=1 p=N409
t=520 y=2011 r=2 p=N409
t=520 y=2011 r=3 p=N409
The... (4 Replies)
Just want to say this is great resources for all thing Unix!!
cat tmp.txt
A 3
C 19
A 2
B 5
A 1
A 0
C 13
B 9
C 1
Desired output:
A 3
B 9
C 19
The following work but I am wondering if there is a better way to do it: (4 Replies)
There are some duplicate field on description column .I want to print duplicate row along with highest version of number and corresponding description column.
file1.txt
number Description
=== ============
34567 nl21a00is-centerdb001:ncdbareq:Error in loading init
34577 ... (7 Replies)
How to print the names with a highest value within a set and filter if it is the only unique group within the same set
input
sets names value groups
j007 shot1 0.6 a
j007 shot2 0.5 b
j007 shot3 0.4 bb
j007 shot4 0.3 bc
j007 shot5 0.2 ... (8 Replies)
Hi, I have a little issue right now.
I have a file with 4 columns
test0000002,10030010330,c_,218
test0000002,10030010330,d_,202
test0000002,10030010330,b_,193
test0000002,10030010020,c_,178
test0000002,10030010020,b_,170
test0000002,10030010330,a_,166
test0000002,10030010020,a_,151... (2 Replies)
Hi, I have a little issue right now.
I have a file with 4 columns
test0000002,10030010330,c_,218
test0000002,10030010330,d_,202
test0000002,10030010330,b_,193
test0000002,10030010020,c_,178
test0000002,10030010020,b_,170
test0000002,10030010330,a_,166
test0000002,10030010020,a_,151... (3 Replies)
grepping on a value but then want to print only those lines that have the highest value in the 4th column
log text text R59FJ
log text text R63FT
log text text R60JX
log1 text text R63EA
log1 text text R60JX desired output
log text text R63FT
log1 text text R63EAtried this but not getting... (2 Replies)
Discussion started by: jimmyf
2 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)