<blockquote>
<p>Since the copy of same data is stored on each node in network. Does it use storage space to store same data on each node?</p>
</blockquote>
<p>Yes, but what matters is the validation of the data. Therefore you can use pruning to validate the block chain data without the storage overhead.</p>
<blockquote>
<p>If yes then how the data is decentralised. It is just a large network of centralised database.</p>
</blockquote>
<p>What can be called decentralisation in the case of Bitcoin is the ability of being able to retrieve the current state of the network without having to trust a central source of validation (/truth). This is accomplished through the validation of the block chain.</p>

CC BY-SA 4.0
2020-05-09T18:41:53.153Z
Thanks, however since same block is store on every node it will going to occupy storage space on each block. Right? What is pruning?
siddharth shah
CC BY-SA 4.0
2020-05-09T22:37:31.470Z
@siddharthshah Pruning is decribed in  [Satoshi Nakamoto's whitepaper](https://bitcoin.org/bitcoin.pdf). See also https://bitcoin.stackexchange.com/search?q=pruning
RedGrittyBrick
CC BY-SA 4.0
2020-05-10T09:15:37.553Z
@siddharthshah pruning is the action of erasing the block data once validated it and filtered out what you needed to update your state. In addition to the above links, https://github.com/bitcoin/bitcoin/blob/v0.11.0/doc/release-notes.md#block-file-pruning .
Antoine Poinsot
CC BY-SA 4.0
2020-05-10T19:13:10.933Z
Understood, but it's storing same data on all the node in the network too much residency? In the age of big data I can be a major issue
siddharth shah
CC BY-SA 4.0
2020-05-09T17:57:42.357Z
2020-12-10T19:20:40.277Z
2020-12-10T19:20:40.277Z
Antoine Poinsot
<blockquote>
  <p>If yes then how the data is decentralised. It is just a large network of centralised database.</p>
</blockquote>

<p>When people use the term <em>decentralized</em>, they mean that there is no central point of authority; no heirarchy to the network's nodes. </p>

<p>Each bitcoin full node validates the full network state, which allows them to participate in the network without having to trust any specific peer to provide them with truthful information. This is an important property of the network. </p>

<p>What you seem to be implying is that the blockchain history data itself should be stored/communicated in a decentralized way. But if each node was not able to fully verify the entirety of the data itself, then it would have to trust that other nodes in the network have verified the info it is missing. This is an issue, since now every node will have to trust third party nodes to provide truthful updates. Under this model, we lose the very important aspect of trustless participation, and instead end up with a Byzantine mess. </p>

CC BY-SA 4.0
2020-05-10T19:12:51.470Z
Understood, but it's storing same data on all the node in the network too much residency? In the age of big data I can be a major issue
siddharth shah
CC BY-SA 4.0
2020-05-10T21:58:50.277Z
Why would that be an issue? I'm not sure I understand your worry, can you elaborate?
chytrik
CC BY-SA 4.0
2020-05-10T02:47:07.007Z
2020-05-10T02:47:07.007Z
chytrik
<p>Since the copy of same data is storedon each node in network. Does it use storage space to store same data on each node? </p>

<p>If yes then how the data is decentralised. It is just a large network of centralised database.</p>

<p>Any help would be appreciated.</p>

CC BY-SA 4.0
2020-05-09T14:11:07.613Z
In Bitcoin every (full-)node stores every full block. In Ethereum, what you're referring to is called [Sharding](https://github.com/ethereum/wiki/wiki/Sharding-roadmap) (though I don't know if it's active on the main Ethereum network). https://ethereum.stackexchange.com may inform you about that.
MCCCS
<bitcoin-core><blockchain><ethereum>
Problem with data redundancy in block chain
siddharth shah
# Problem with data redundancy in block chain

(Asked by: username_0 on 2020-05-09)

Since the copy of same data is storedon each node in network. Does it use storage space to store same data on each node?

If yes then how the data is decentralised. It is just a large network of centralised database.

Any help would be appreciated.

**Tags:** bitcoin-core, blockchain, ethereum

> **Comments:**
> **username_1**: In Bitcoin every (full-)node stores every full block. In Ethereum, what you're referring to is called [Sharding](https://github.com/ethereum/wiki/wiki/Sharding-roadmap) (though I don't know if it's active on the main Ethereum network). https://ethereum.stackexchange.com may inform you about that.  

---

## 2 answers

### Answer by username_2 on 2020-05-09. Score: 3

> Since the copy of same data is stored on each node in network. Does it use storage space to store same data on each node?

Yes, but what matters is the validation of the data. Therefore you can use pruning to validate the block chain data without the storage overhead.

> If yes then how the data is decentralised. It is just a large network of centralised database.

What can be called decentralisation in the case of Bitcoin is the ability of being able to retrieve the current state of the network without having to trust a central source of validation (/truth). This is accomplished through the validation of the block chain.

> **Comments:**
> **username_0**: Thanks, however since same block is store on every node it will going to occupy storage space on each block. Right? What is pruning?  
> **username_3**: @username_0 Pruning is decribed in  [Satoshi Nakamoto's whitepaper](https://bitcoin.org/bitcoin.pdf). See also https://bitcoin.stackexchange.com/search?q=pruning  
> **username_2**: @username_0 pruning is the action of erasing the block data once validated it and filtered out what you needed to update your state. In addition to the above links, https://github.com/bitcoin/bitcoin/blob/v0.11.0/doc/release-notes.md#block-file-pruning .  
> **username_0**: Understood, but it's storing same data on all the node in the network too much residency? In the age of big data I can be a major issue  

---

### Answer by username_4 on 2020-05-10. Score: 1

> If yes then how the data is decentralised. It is just a large network of centralised database.

When people use the term *decentralized*, they mean that there is no central point of authority; no heirarchy to the network's nodes.

Each bitcoin full node validates the full network state, which allows them to participate in the network without having to trust any specific peer to provide them with truthful information. This is an important property of the network.

What you seem to be implying is that the blockchain history data itself should be stored/communicated in a decentralized way. But if each node was not able to fully verify the entirety of the data itself, then it would have to trust that other nodes in the network have verified the info it is missing. This is an issue, since now every node will have to trust third party nodes to provide truthful updates. Under this model, we lose the very important aspect of trustless participation, and instead end up with a Byzantine mess.

> **Comments:**
> **username_0**: Understood, but it's storing same data on all the node in the network too much residency? In the age of big data I can be a major issue  
> **username_4**: Why would that be an issue? I'm not sure I understand your worry, can you elaborate?  

---

