Hi Friends,
I want to delete specific columns from a file.
Say my file content is as follows:
"1","a","ww1",1234"
"2","b","wwr3","2222"
"3","c","erre","3333"
Now i want to delete the column 2 and 4 from this file.
That is I want the file content to be:
"1","ww1"
"2","wwr3"... (11 Replies)
Hi,
I would like to know how can I find the number of columns in each line in a csv file.
I have a csv file wiht comma separated an dhas 10000 line in it.
I want to verify the number of columns in each line.
is there any way to find it out using awk or any other commands?
Thanks.... (2 Replies)
Hi All,
Am working on perl script which should delete columns in existing CSV file.
If my file is :
AA,BB,CC,DD
00,11,22,33
00,55,66,77
00,99,88,21
AA,BB... are all my headers can come in any order (e.g AA,CC,BB...) and rest are values. I want to delete column CC...
Can anybody help... (2 Replies)
Dear specialists out there, please help a poor awk newbie:
I have a very huge file to process consisting of 300000 columns and 1500 rows. About 20000 columns shall be deleted from that file. So it is clear, that I can't do this by writing down all the columns in an awk command like $1, $x etc.... (5 Replies)
Hi All,
I have two .csv's
input.csv having values as (7 columns)
ABC,A19907103,ABC DEV YUNG,2.17,1000,2157,07/07/2006
XYZ,H00213850,MM TRUP HILL,38.38,580,23308,31/08/2010
output.csv having (25 columns)
A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y... (4 Replies)
Hi Friends,
I have come across some files where some of the columns don not have data.
Key, Data1,Data2,Data3,Data4,Data5
A,5,6,,10,,
A,3,4,,3,,
B,1,,4,5,,
B,2,,3,4,,
If we see the above data on Data5 column do not have any row got filled. So remove only that column(Here Data5) and... (4 Replies)
Hi all, I'm pretty much a newbie to UNIX. I would appreciate any help with UNIX coding on comparing two large csv files (greater than 10 GB in size), and output a file with matching columns.
I want to compare file1 and file2 by 'id' and 'chain' columns, then extract exact matching rows'... (5 Replies)
Hi,
I have a file of csv data, which looks like this:
file1:
1AA,LGV_PONCEY_LES_ATHEE,1,\N,1,00020460E1,0,\N,\N,\N,\N,2,00.22335321,0.00466628
2BB,LES_POUGES_ASF,\N,200,200,00006298G1,0,\N,\N,\N,\N,1,00.30887539,0.00050312... (10 Replies)
Hi,
I have 2 csv files with 15 000 lines, which looks like this:
Daily.csv
"CODE","BRAND","DESIGNER","SIZE","TYPE","GENDER","SET","DESCRIPTION","IMAGE","COST","WEIGHT","MSRP","UPC"
"M-1001","212","Caroline Her","1.7 oz","EDT... (4 Replies)
Discussion started by: olivieraz
4 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)