I have two files one (numbers file)contains the numbers(approximately 30000) and the other file(record file) contains the records(approximately 40000)which may or may not contain the numbers from that file.
I want to seperate the records which has the field 1=(any of the number from numbers... (15 Replies)
Hi All,
I have two files say file1 and file2.
I want to check the number of records in file1 and if its atleast 2 (i.e., 2 or greater than 2 ) then I have to check records in file2 .If records in file2 is atleast 1 (i.e. if its not empty ) i have to set some conditions .
Could you pls... (3 Replies)
i have a pipe delimited file with records spread in many lines.
i need to extract those records
1)having X in beginning of that record
2)and having at least one Y in beginning before other record begins
eg:
X|Rec1|
A|Rec1|
Y|Rec1|
X|Rec2|
Y|Rec2|
Z|Rec3|
X|Rec4|
M|Rec4|
... (4 Replies)
I have a file with 50,000 records in it, i have a requirement to use the same 50,000 records and add them 4 times to the same file to make a total of 200,000 records. I was wondering how to do this using ksh. Any help is greatly appreciated. (2 Replies)
Hello guys this is my first post in this forum. Since now ive been passive an ive only been looking for existing information. Now I could use specific help on a UNIX script i want to make that would:
1. Take 1-3 arguments.
2. Display the contents of its arguments, formatted as follows:... (7 Replies)
Discussion started by: banzomaster
7 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)