Skip to main content
Share Your Experience: Take the 2024 Developer Survey

Questions tagged [storage]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
43 votes
9 answers
13k views

Understanding serialization

I am a software engineer and after a discussion with some colleagues, I realized I do not have a good grasp of the concept serialization. As I understand, serialization is the process of converting ...
ddcz's user avatar
  • 533
16 votes
8 answers
6k views

Why we still need Short Term Memory if Long Term Memory can save temporary data?

If RAM is a short term memory and SSD is a long term memory, why don't microarchitecture of computer nowadays use SSD or another long term memory for saving temporary data like hidden variable for ...
Muhammad Ikhwan Perwira's user avatar
8 votes
4 answers
9k views

Is the 2nd parity bit in RAID 6 a simple calculation?

I'm trying to understand how the 2nd parity bit or byte is set in RAID 6. I'm reading a paper by H. Peter Anvin, and it goes into Galois field algebra, which is somewhat new to me. Anyway, a rep from ...
Mitchell Kaplan's user avatar
8 votes
0 answers
84 views

Distributed Storage for Access and Preservation

My organization wants to maintain multiple copies of data in order to preserve access in the case of localized disasters as well as for the purpose of long term preservation. Are there accepted formal ...
Micah Beck's user avatar
7 votes
3 answers
866 views

What is the minimum required storage for a sparse, depth-first octree?

For a numerical simulation framework, I use a hierarchical Cartesian grid in 3D to discretize the computational domain. I am thus looking for the most space-efficient way to store the resulting octree ...
Michael Schlottke-Lakemper's user avatar
5 votes
4 answers
460 views

A "triangular" data structure for commutative relationships

A multiplication table is symmetric over a diagonal, so only about $n^2/2$ of the elements in an $n \times n$ multiplication table contain unique information. Same goes for addition tables. In fact, ...
Qaz's user avatar
  • 153
5 votes
2 answers
2k views

What course in CS deals with the study of RAM, CPU, Storage?

I watched the Crash Course playlist of Computer Science. It was teaching about RAM, CPU, Storage etc but I felt it was way too fast and only people who have studied the course first hand understood it ...
Rifat's user avatar
  • 59
5 votes
3 answers
3k views

Does the performance of matrix multiplication depend on the storage of the array?

Two matrices can be stored in either row major or column major order in contiguous memory. Does the time complexity of computing their multiplication vary depending on the storage scheme? That is, I ...
Kapes's user avatar
  • 163
5 votes
1 answer
2k views

Why does RAID-5 require an additional disk for parity blocks?

I know that RAID-5 consists of block-level striping across multiple disks, but using an additional parity-check block on each disk .. and that at least two disks are required for striping. And it's ...
user6039980's user avatar
5 votes
1 answer
585 views

Could a standardized ternary system be more efficient than the binary system? [duplicate]

Could a standardized ternary (base-3) system be more efficient than the binary (base-2) system? Binary is efficient for processing using logic gates, but can be bulky when using for file storage or ...
JaceVoracek's user avatar
4 votes
1 answer
3k views

Why do some filesystems have fragmentation and others don't?

I try to understand why fragmentation is a problem for NTFS and FAT but not when using inodes. In all cases, files are not necessarily stored in a contiguous fashion so I don't see the problem for the ...
user2459338's user avatar
4 votes
0 answers
64 views

Extending the causal memory model to wide-area distributed storage systems

In the seminal paper "Causal memory: definitions, implementations, and programming", distributed causal memory is defined to ensures that all the processes in a system agree on the relative ordering ...
hengxin's user avatar
  • 9,561
3 votes
4 answers
2k views

time efficient key value store for fast lookup

Let's state a collection of key/values. Key is an unsigned integer (0 - 2^32-1). Hense there are comparable. Value is few bytes fixed size. There are 4M items in the collection. Keys are not evenly ...
Setop's user avatar
  • 131
3 votes
1 answer
119 views

A data structure for an allocation-free dynamic sample rate buffer

I'm looking for a data structure that would allow storing samples (in O(1)) from a data stream in a fixed-size buffer while the stream length isn't known in advance. Once the buffer size is exhausted ...
Eugene Pankov's user avatar
3 votes
1 answer
183 views

Is there a name for "density" of information?

If we compare multimedia and text, if we have n bytes of text and compare it with n bytes of video, then we would be likely to think that n bytes of text is "more" information than n bytes of video ...
Niklas Rosencrantz's user avatar
3 votes
1 answer
72 views

A doubt on best media for a time capsule

So, I have some data to a time capsule project of mine. But the thing is, I need to know the best media on long-time scale to use as storage unity. The time range is 120 years. Now, I've been thinking ...
M.N.Raia's user avatar
  • 141
3 votes
0 answers
55 views

What data structure should I use for storing my data?

I am currently looking for a way in which I can store my data, and quickly look it up. What currently seem to be the best idea is to use a hash map. reasons: To identify what item I am looking for, ...
user25778's user avatar
  • 131
3 votes
0 answers
162 views

Representing Computations on Transcendental Numbers

Consider the set of transcendental numbers that are not compressible to a finite base-2 representation. How can I compute multiples (more generally, any algebraic computation) of one of these numbers,...
geofflittle's user avatar
2 votes
1 answer
6k views

SSTF disk scheduling algorithm? What if lowest seek times are equal in either direction?

Using the Shortest-Seek-Time-First (SSTF) disk scheduling algorithm (where we select a request with a minimum seek time from the current head position), what happens if the requests in both directions ...
Ciaran Gallagher's user avatar
2 votes
2 answers
5k views

Is ROM primary memory or secondary memory?

According to this picture ROM is classified under Main Memory , but isn’t ROM a secondary storage because it’s external and non volatile ? Any clarification with reference links will be highly ...
Allen Hay's user avatar
2 votes
1 answer
199 views

Using B+Tree to implement index, when the index-key size and the data-block size are of the same order

I want to implement an Index using a B+Tree as the underlying data structure. The index will have to support key sizes which are of order of my block size, what means I cannot save all the key as a ...
user5721565's user avatar
2 votes
1 answer
1k views

Calculate storage requirements for a data set

I have a simple problem. I can't seem to even find the right search terms to get me pointed in the direction I need to be heading. I'm writing a bunch of integers to disk. Lot's of them. Starting ...
lmizuhashi's user avatar
2 votes
1 answer
67 views

Course teaching time complexities in real life systems

Having mis-read What course in CS deals with the study of RAM, CPU, Storage? I now wonder what course in CS deals with time and space complexities including GPUs, CPU caches in multiple levels, seek ...
Ole Tange's user avatar
  • 121
2 votes
1 answer
577 views

Page cache and its relationship to page table

I was reading about the page cache Page cache - the cache in memory for files, but I couldn't find the answer to my question. Does the page table have anything to do with, or maintain any entries, for ...
flow2k's user avatar
  • 123
2 votes
0 answers
39 views

Primary File Organization in DBMS - Files of ordered records (sorted files)

"Fundamental of Database Systems", 3rd ed. by Elmasri and Navathe, page 136 says: "We can physically order the records of a file on disk based on the values of one of their fields [...]&...
GuestUser's user avatar
2 votes
0 answers
195 views

Regarding Amdahl's balanced system law

One of the paper titled "Rules of Thumb in Data Engineering" (Jim Gray et. el.) mentions some calculations based on Amdahl's balanced system law. Link to paper: https://www.microsoft.com/en-us/...
user108161's user avatar
2 votes
0 answers
52 views

Can you read a file as a binary number?

This is a pretty naive question, but I would like to better understand the basics of information storage on a computer. I am not concerned with the detail of how any one operating system achieves ...
Colin McLarty's user avatar
2 votes
4 answers
7k views

Difference between Sequential ,Direct and Random acess with their acess time

I'm stuck on a point while reading about these different accessing methods. As per author. Sequential access Memory is organized into units of data, called records.Access must be made in a ...
Nikhil Badyal's user avatar
2 votes
1 answer
628 views

What exactly is a "binary file"?

I suspect this may be more of a concept / theory question, but, I haven't been able to wrap my brain around what exactly a binary file is. I've read links such as the below: https://en.wikipedia.org/...
Player_2's user avatar
1 vote
2 answers
118 views

Why don't hard drives actually delete data?

As far as I understand it, when you delete a file from trash/recycle bin the file isn't actually erased from memory but is instead marked as being okay to be over written. So, my question is as to ...
guest12345's user avatar
1 vote
1 answer
55 views

Why did the concept of "write-protecting" not carry over from floppy disks to USB memsticks and especially external USB HDDs? [closed]

Many times, I've wished to plug in my backup hard disks into my PC without the risk of any of the data being deleted, overwritten, or modified in any manner. Purely for "inspection" and ...
Diran E's user avatar
  • 11
1 vote
1 answer
989 views

Processes and Segmentation

The following problem was on my final and in Gate 2006, but I don't understand how to solve it: Different methods of memory management have different overheads: ...
nightrider's user avatar
1 vote
1 answer
734 views

How are the number of bytes less than the number of pixels in an image?

Lets take, for example this jpeg image here The image there is 400 x 300, or 120000 pixels and The file size of the image (on my computer) is shown to be 65171 bytes. This means the computer stores ...
Adam Brady's user avatar
1 vote
2 answers
115 views

How can I write 2^65 on my 64-bit computer?

This is possibly a very trivial question for this site. If I have a 64-bit laptop that means 2^64 combinations in total are possible. But I can even get $2^{(x>>>64)}$ on my laptop. Now, it ...
Lost's user avatar
  • 113
1 vote
1 answer
62 views

Why is data stored on a flash disk irretrievable if the memory chip is cracked? [closed]

All data recovery companies, regardless of skill, unanimously say that if the memory chip of a device has just a hair line crack, data recovery is impossible. Not unlikely, not expensive, but ...
Starkers's user avatar
  • 119
1 vote
2 answers
77k views

What is the difference between storage media and storage devices [closed]

I am having a rather distressing confusion about whether storage media and storage devices are the same terms. I found on this ...
swdeveloper's user avatar
1 vote
1 answer
48 views

Is reading contiguous pages (let's say 4KB) any faster than reading non-contiguous pages on SSDs?

I'm working my way on a problem which requires me to store elements in fixed 4KB-sized pages on an SSD. Each page is requested once for some computation on its elements, and then the CPU requests for ...
Shikhar Jaiswal's user avatar
1 vote
1 answer
44 views

Fair assignment of storage for multiple writers (load balance)

I'm trying to optimize a system with a better algorithm for allocating storage. The system has 'N' writer processes and 'M' disks. (N < 30, M < 10. N can change, M is constant). Any process can ...
Danny's user avatar
  • 111
1 vote
1 answer
214 views

How can I formalize key value stores with set theory?

I'm currently developing a simple key-value NoSQL store and want to build its formal model. I found article about key value formalisation with category theory, but I'm interested are there some works ...
MainstreamDeveloper00's user avatar
1 vote
2 answers
58 views

Why is the default page/block size 4 KiB?

Clearly, some empirical study on an older machine helped us choose a 4KiB page size to balance TLB hit rate and fragmentation. Modern hardware and operating systems support this size for backward ...
idle_cycles's user avatar
1 vote
0 answers
34 views

Does Nand Flash Type Affect the Read Latency Based on Page Content?

In general, we have these types of NAND flash cells: SLC, MLC, TLC, and QLC. Since MLC flash cells can store 2 bits, the content of the cell can be 00, 01, 10, or 11 which are detected using different ...
Arghavan Mohammadhassani's user avatar
1 vote
0 answers
22 views

Why do we need volume as an abstraction on top of partition?

I'm curious about what do we need volume as an abstraction on top of hardware partition? What problem it tries to solve? What is the limitation of this concept?
zack's user avatar
  • 196
1 vote
0 answers
34 views

How extended logical blocks are mapped to physical device pages?

I'm reading "Decibel: Isolation and Sharing in Disaggregated Rack-Scale Storage" (PDF). On page 6, the author illustrates the concept of "Extended Logical Block"), which is similar to "Data Integrity ...
Majid Azimi's user avatar
1 vote
0 answers
624 views

How to calculate multibit trie storage size?

I wish to use a multi-bit trie structure for storing IPv4 forwarding information with a fixed stride width of 8 bits, I think this is also called a "radix of 8" (so for any IP prefix 4 levels will ...
Baldrick's user avatar
  • 111
0 votes
2 answers
46 views

When a CPU copies instructions from storage into RAM how does it jump to instructions no longer in RAM?

When a CPU needs to get more instructions from storage and copies them to RAM, how does the CPU jump to previous instructions that are no longer in the RAM? Would it have to copy the old instructions ...
Thenboy's user avatar
  • 11
0 votes
1 answer
118 views

How can computers tell where the beginning and end of file/packet/frame headers are?

I'd like to know how a computer can determine the beginning and end of certain file components (attributes, headers, frame/packet/segment headers etc.) when these components can be omitted or added in ...
Inquisitive's user avatar
0 votes
1 answer
42 views

Confusion with Hard Disk structure

Studying Os development I encountered the need to interface with the Hard Disk Drive and thus i started learning how it actually works. One of the problems that i found studying was that different ...
Mastcharub's user avatar
0 votes
1 answer
2k views

How is the data stored in AVL tree in a memory? [duplicate]

I have been struggling to visualize how is the AVL tree is stored in memory? Does it store data in array or list, If so how is it connected with its child and parents.
Reboot's user avatar
  • 15
0 votes
1 answer
261 views

Most Efficient Way to List All $n$-bit Permutations

Suppose we are tasked with expressing a randomized list of all numbers up to but excluding $2^n$ (ie. a random list of all n-bit numbers). What are some efficient ways to do such a listing using as ...
David C's user avatar
  • 103
0 votes
1 answer
2k views

Why do computers use binary, instead of ternary, or some other logic system? [duplicate]

In binary a unit (bit), can store 2 separate values. if you have ternary, then a unit can store 3 separate values. why then don't computers use higher bases, for example in ternary you could have 3 ...
matultimate's user avatar