Hi, can anyone explain me how this works (how the flow goes)?
Example:
CLIENT="UNIXHELP"
The second argument passed $2="UNIX"
RESULT=`awk -F"=" '/CLIENTS=/ {len = index($2,"'${CLIENT}'");print len }' $2`
Thanks in advance. (1 Reply)
hi, :)
In a shell script i came accross the following lines
1.for i in ` find /home/oracle -name ch'
2.do
3.echo $i
4.idx=`expr index $i .`
5.done
Here iam not able to understand the porpose of the word "index" in line 4.
any help ?
cheers
RRK (3 Replies)
Hi all,
I am using Legato networker for my backups, I need to restore some data from 2001.
When doing an inventory on the tape is picks up the label but under pool it says "not in media index".
When doing: nsrck -t 01Jan2002 -L7 i get the following:
nsrck: checking index for '$client'... (2 Replies)
why do inode indices starts from 1 unlike array indexes which starts from 0
its a question from "the design of unix operating system" of maurice j bach
id be glad if i get to know the answer quickly
:) (0 Replies)
brothers why inode index starts from 1 unlike array inex which starts from 0
its a question from the design of unix operating system of maurice j.bach
i need to know the answer urgently...someone help please (1 Reply)
Hi All,
I have a file (FileNames.txt) which contains the following data in it.
$ cat FileNames.txt
MYFILE17XXX208Sep191307.csv
MYFILE19XXX208Sep192124.csv
MYFILE20XXX208Sep192418.csv
MYFILE22XXX208Sep193234.csv
MYFILE21XXX208Sep193018.csv
MYFILE24XXX208Sep194053.csv... (5 Replies)
1 2 000060000
How do i return the point in the string where the 6 is?
i.e what I want on output is
1 2 5
something like awk '{print $1 $2 index($3,6) }'
but I can't get it to work
Thanks in advance (3 Replies)
HI All,
I would like to pass a integer and get all values under this index the by using awk. Could anyone help?
Thanks :>
input:
1,2,3,4,5,6,7
1,2,3,48,5,6,7
1,2,3,4,5,6,7
e.g. i pass 4 to awk command
output:
4
48
4
Video tutorial on how to use code tags in The UNIX and Linux... (8 Replies)
Hi guys,
I have postgresql server with huge amount of data, nearly 2 billion records. each record is at most 50 bytes(4 integer fields). I need to build index on all column to do fast reporting. but indexes becomes bloat after some time. almost 80% of database size is because of its huge... (0 Replies)
Hello Gents,
Please give a help with this case
Input
10001010G1
10001010G1
10001010G1
10001010G2
10001010G3
10001012G1
10001012G1
10001012G1
10001012G1
10001014G1
10001014G1
10001014G2 (5 Replies)
Discussion started by: jiam912
5 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)