A million fields per line is quite ambitious, and I'd wonder what it be for. This
is quite lengthy already, for i<=32767 it takes ages, and for i > 32768 it fails (on my system).
Try this
Here is an easy game!
I wrote a number between 0 and 20 (that can include 0 and 20) on a piece of paper. I am staring at it now, imagining the number so you can read my mind ;)
Reply once, and only once, with a number from 0 to 20 and the first person to guess it wins 1,000,000 Bits.
... (24 Replies)
Hi all,
I have created a script which adding two columns and removing two columns for all files.
Filename: Cust_information_1200_201010.txt
Source Data:
"1","Cust information","123","106001","street","1-203 high street"
"1","Cust information","124","105001","street","1-203 high street"
... (0 Replies)
Dear All,
I have two files both containing 10 Million records each separated by comma(csv fmt).
One file is input.txt other is status.txt.
Input.txt-> contains fields with one unique id field (primary key we can say)
Status.txt -> contains two fields only:1. unique id and 2. status
... (8 Replies)
Hi all, I know this sounds suspiciously like a homework course; but, it is not.
My goal is to take a file, and match my "ID" column to the "Date" column, if those conditions are true, add the total number of minutes worked and place it in this file, while not printing the original rows that I... (6 Replies)
HI All,
I'm embedding SQL query in Script which gives following output:
Assignee Group Total
ABC Group1 17
PQR Group2 5
PQR Group3 6
XYZ Group1 10
XYZ Group3 5
I have saved the above output in a file.
How do i sum up the contents of this output so as to get following output:
... (4 Replies)
Hi all,
I am kind of stuck with printing my desired output. Please help me if you know how it can work.
My input file(tab separated):
NW_0068.1 41,16 100,900
NW_0699.1 4,2,19 200,700,80
My Output file (desired):
NW_0068.1 41,16 100,900 100 - 141
NW_0068.1 41,16 100,900 ... (3 Replies)
Dear Experts,
I have input file which is comma separated, has 4 columns like below,
BRAND,COUNTRY,MODEL,COUNT
NIKE,USA,DUMMY,5
NIKE,USA,ORIGINAL,10
PUMA,FRANCE,DUMMY,20
PUMA,FRANCE,ORIGINAL,15
ADIDAS,ITALY,DUMMY,50
ADIDAS,ITALY,ORIGINAL,50
SPIKE,CHINA,DUMMY,1O
And expected output add... (2 Replies)
Discussion started by: ricky1991
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)