Solved

reading index file

Posted on 2013-06-04
3
291 Views
Last Modified: 2013-06-18
In my application, I see b-trees are populated in memory and is stored persistenty on file on the system also. How can I read this file, as I need to replace all the values of keys due to change in data structure of value
0
Comment
Question by:perlperl
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
3 Comments
 
LVL 84

Expert Comment

by:ozo
ID: 39219146
That depends on your application.
Does your application have a function to read the file?
Can you determine the file format your application uses to store  b-trees?
0
 
LVL 34

Expert Comment

by:sarabande
ID: 39219488
if you have the store function you easily could deduce the read function from it (if not already exists as mentioned by ozo). in some cases the stored data was encrypted and needs decryption when read from file.

normally a stored b-tree would be read at initialization phase into memory. it is much likely that it has fixed-record length and binary data.

changing the keys will arise problems in a b-tree as the keys are sorted and (normally) are stored in packed format. so any change in length or value would make the tree invalid as long as you don't use the built-in remove and insert functions.

Sara
0
 
LVL 15

Accepted Solution

by:
Minh Võ Công earned 500 total points
ID: 39253330
This is a sample implementation B-tree in file

http://forum.codecall.net/topic/41058-b-tree-c-implementation/
0

Featured Post

Free Tool: Postgres Monitoring System

A PHP and Perl based system to collect and display usage statistics from PostgreSQL databases.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Resolve Dependency Issues 4 87
How to convert Structure to vector of byte and vice versa 5 31
Outlook 13 84
Are the two lines the same? If not what is the difference? 2 29
This article shows you how to optimize memory allocations in C++ using placement new. Applicable especially to usecases dealing with creation of large number of objects. A brief on problem: Lets take example problem for simplicity: - I have a G…
Container Orchestration platforms empower organizations to scale their apps at an exceptional rate. This is the reason numerous innovation-driven companies are moving apps to an appropriated datacenter wide platform that empowers them to scale at a …
Video by: Grant
The goal of this video is to provide viewers with basic examples to understand and use for-loops in the C programming language.
The viewer will learn how to clear a vector as well as how to detect empty vectors in C++.

696 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question