Hi,
I have the following data in the format as shown (note: there are more than 1 blank spaces between each field and the spaces are not uniform, meaning there can be one blank space between field1 and field2 and 3 spaces between field3 and field4, in this example, # are the spaces in between... (19 Replies)
Hello,
I have two files that I need to compare and print out the line from file2 that has the first 6 fields matching the first 6 fields in file1. Complicating this are the following restrictions
1. file1 is only a few thousand lines at most and file2 is greater than 2 million
2. I need to... (7 Replies)
Hi,
I have a sql file that runs something like this
vi Test.sql
REVOKE EXECUTE ON DEMO_USER.SQC_SAMP FROM PUBLIC;
REVOKE EXECUTE ON DEMO_USER.SQC_SAMP FROM DEMO_READ;
REVOKE SELECT ON DEMO_USER.DEMO_NOMINEE_TEST FROM DEMO_READ;
REVOKE EXECUTE ON DEMO_USER.SQC_SAMP FROM... (3 Replies)
Hello,
I am checking the length of each line of a fixed length file and making sure all lines are 161 length. My problem is that some files contain null characters which gets stripped out of my echo. How do I have the NULLs included in my check? (and I cannot replace or sub the NULL values with... (10 Replies)
Hi,
I have a log file which has number of lines from that i have to grep a string like this
03:22:19,287
while greping this string i have to grep next lines to the maximum of finding the word (MORE...)
the stack is like this
*************
22/11/2011 03:22:19,287 232290646 ERROR... (2 Replies)
I am trying to selectively display several columns from a db2 query, which gives me a fixed-width output (partial output listed here):
--------- -------------------------- ------------ ------
000 0000000000198012 702 29
000 0000000000198013 ... (9 Replies)
Hi,
i have a scenario were i should compare a few fields from each line then increment a variable based on that.
Example file
989878|8999|Y|0|Y|N|V
989878|8999|Y|0|N|N|V
989878|8999|Y|2344|Y|N|V
i have 3 conditions to check and increment a variable on every line
condition 1 if ( $3... (4 Replies)
Hi All:
I need your help please.
I have a include file *.awk , and I would want to know if it's there a option's awk where I can use this file include, for example:
awk -f decodifica_bitmap.awk cadena_hex.txt -e /home/snh/Awk/include/funciones.awk > sal.out
it give error:
awk:... (1 Reply)
Hi guys I am trying to figure out how to match a pattern with a regex up to a full blank line. I will show you what I mean with this example:
example A
movie name: ted
movie name: TMNT
movie name: Jinxed
example B
movie names:
Gravity
Faster
Turbo
song titles:
dont
hello
problem (8 Replies)
Discussion started by: acoding
8 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)