Ethereum as database
just like bitcoin, Ethereum is neither controlled nor owned by anyone - it is an open source project created by many people around the world. Different from bitcoin protocol, Ethereum's design is very flexible and adaptable. It is very easy to create new applications on the Ethereum platform. With the release of homestead, anyone can use the applications on this platform safely
Ethereum is a programmable blockchain. It does not give users a series of preset operations, but allows users to create complex operations according to their own wishes. In this way, it can be used as a platform for many types of decentralized blockchain applications
in a narrow sense, Ethereum refers to a series of protocols that define a decentralized application platform. The core of Ethereum is Ethereum virtual machine (EVM), which can encode any complex algorithm. In computer science terminology, Ethereum is "Turing complete.". Developers can use the existing JavaScript and python as the model of other friendly programming languages to create applications running on the Ethereum simulator.
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DTV share, Ethereum is an open source public blockchain platform with intelligent contract function. It provides decentralized virtual machines to handle point-to-point contracts through its private cryptocurrency, Ethernet. Key points: open source, smart contract function, public chain platform, Ethernet
what is Ethereum:
Ethereum is an innovation based on the application of technologies and concepts in bitcoin to computers. Ethereum itself imitates a lot of bitcoin technology to maintain the computer platform. Blockchain technology is one of them
Ethereum platform can safely run any program users want
advantages of Ethereum over other competitive currencies before Ethereum appeared, some digital currencies imitated bitcoin. However, these projects have their own shortcomings, they can only support one or several specific applications at the same time< However, the reason why Ethereum can surpass the limitations of these projects in the past is because of the core idea of Ethereum
what Ethereum wants to implement is a blockchain protocol with built-in programming language. Since it supports programming language, in theory, any blockchain application can be defined with this language, and then run on Ethereum's blockchain protocol as an application
The design of Ethereum is very flexible and adaptable
Ethereum target sets the advantages of blockchain technology, in order to add the advantages of blockchain, such as decentralization, openness and security, to almost all computing fields
blockchain applications of Ethereum
Ethereum has many blockchain applications, such as digital applications of gold and stocks, financial derivatives applications, DNS and digital authentication, etc
Ethereum has achieved more than 100 blockchain applications by many start-ups
Ethereum has also been closely watched by some financial institutions, banking consortia (such as R3), as well as large companies like Samsung, Deloitte, RWE and IBM. As a result, a number of blockchain applications such as simplified and automated financial transactions, merchant loyalty index tracking, and gift cards designed to achieve decentralization of electronic transactions have emerged
the relationship between Ethereum and blockchain:
Ethereum is a programmable blockchain
Ethereum does not give users a series of preset operations (such as bitcoin transaction), but allows users to create complex operations according to their own wishes
in this way, Ethereum can be used as a platform for various types of decentralized blockchain applications, including but not limited to cryptocurrency
like other blockchains, Ethereum also has a peer-to-peer network protocol. Ethereum blockchain database is maintained and updated by many nodes connected to the network. Each network node runs the Ethereum simulator and executes the same instructions. Therefore, people sometimes call Ethereum "world computer"
Ethereum is an open source public blockchain platform with smart contract function, which provides decentralized virtual machine (Ethereum virtual machine) to process point-to-point contract through its special cryptocurrency Ethereum. The concept of Ethereum was first inspired by bitcoin by vitalik buterin, a programmer, between 2013 and 2014, and now it's 2.0. Ethereum 2.0 is also something that the whole coin circle is waiting for. In order to celebrate the birth of the genesis block of eth2.0 on December 1, chinacoin officially supports the exchange of eth2.0 verification nodes at 17:00 Hong Kong time on November 20, 2020. It will invest its own eth in the verification node mining and exchange qeth to obtain liquidity. It will participate in the mining as soon as the exchange is received. Now it will give back to the user's welfare. The top 1000 eth enjoy the over exchange of qeth according to the ratio of 1:1.02. Compared with eth2.0, qeth has too many advantages: liquidity is guaranteed, users do not need to bear the technical cost, the threshold of participation does not need 32 eth, as low as 0.1eth, nodes are maintained by the platform, and the revenue is distributed according to eth2.0< br /> < br /> < br />
If you want to query the transaction records on the main network, you can use Etherscan. However, if you build your own private chain, how should you query the transaction records
the answer is that you need to listen to the logs on the chain, save them in the database, and then query them in the database. For example:
< pre t = "code" L = "Java" > varaddr = & quot& quot;< br />varfilter=web3.eth.filter({fromB lock:0 ,toBlock:' latest', address:addr });< br />filter.get(function(err,transactions){transactions.forEach(function(tx){
vartxInfo=web3.eth.getTransaction(tx.transactionHash);
/ / at this time, the transaction information txinfo can be stored in the database
})< br />});
Web3. Eth. Filter() is used to monitor the log on the chain, and Web3. Eth. Gettransaction() is used to extract the information of the specified transaction. Once the transaction information is obtained, it can be stored in the database for query
recommend a practical introction, you can see: Ethereum tutorial
Ethereum is not only a database, it also allows you to run programs in the trusted environment of the blockchain. Ethereum has built a virtual machine named EVM (Ethereum virtual machine) on the blockchain. EVM allows code to be verified and executed on the blockchain, providing guarantee for code to run in the same way on everyone's machine. These codes are included in the smart contract. In addition to tracking the account balance, Ethereum uses the same method to save the EVM status on the blockchain. All nodes process the smart contract to verify the integrity of the contract itself and its output.
there is no central server in Ethereum. Instead, there are many equal nodes connected by P2P protocol, which store all the data in many nodes. When a user initiates a transaction, the transaction will be broadcast out through P2P protocol. The miner node verifies, packages and further broadcasts the transaction to the whole network. After confirmation in the blockchain, the operation is considered to be unchangeable
in the articles on blockchain on the Internet, the two words distributed and decentralized are mentioned, sometimes slightly different, sometimes mixed. The author thinks that if we want to distinguish accurately, the distributed system emphasizes that multiple components work together by sending messages, and the decentralized system emphasizes that there is no central node to control the operation of the whole system. Therefore, we think that Ethereum is both decentralized and distributed, or running a decentralized program on a distributed platform.
in front of the article: the video version is slightly different from the text version. If you want to see my affectionate interpretation, please see the video version (meow understands blockchain phase 22 | sharding: Ethereum is too slow, "disk" him!), The logic of thinking is strange. Please see the extended version
recently, Ethereum has shown an overwhelming positive trend e to the Constantinople upgrade, while Ethereum's upgrade road is like upgrading and fighting monsters, falling into rabbithole. No one knows how deep the hole is. Since it is a long way to go, it is of vital importance to make every step well and accurately. After overcoming this difficulty, Ethereum's next technical difficulty, sharding fragmentation, has been put on the table again. This issue of "meow understands blockchain" will take you into sharding, the magic weapon that makes Ethereum fast
what is sharding
slicing technology is not a new concept. At first, it is an optimization scheme for large central database. Specifically, it divides the data in large database into many shards according to certain rules, and then stores these data in different servers to rece the data access pressure of each server, So as to improve the performance of the whole database system
let's take a small popular example:
for example, meituan, Didi taxi and other software that we often use can be divided according to the "city". Because the data of different cities do not need to communicate, the data of different cities can be stored in different databases, so that the database server can be deployed to the nearest node from the corresponding city, Can also improve the speed of access, why not do it
from the above examples, we should have a preliminary understanding of the concept of fragmentation. What about fragmentation in blockchain scenarios
taking Ethereum fragmentation as an example, in the original single chain system, the overall performance of the public chain depends on the performance of a single node. After fragmentation, each node only needs to undertake the work of the whole network, and each fragmentation works in parallel. According to vitalik, each shard is like a separate galaxy, and each fragmentation is like an independent universe, In this way, the efficiency will be improved naturally! Originally, the total network TPS of Ethereum chain was about 20. Now, if it is increased to 100 pieces, the total network TPS can be increased to 2000. Similarly, the total network capacity will be increased to 100 times of the original
"each node only needs to undertake part of the work of the whole network", which will lead to several major problems. 1. How to determine which piece of work this node is responsible for? 2. Which transactions should be classified into which segments? 3. Does each node only need to store its own transaction information (ledger)
according to the implementation of the above problems, we can divide the fragmentation into three types: network fragmentation, transaction fragmentation and state fragmentation
Network fragmentation: how to divide the nodes of the whole network into different partitions
transaction segmentation: how to divide the whole network transactions into different segments
State fragmentation: how to make each node only maintain the account book in its own fragmentation without affecting the security of the whole system
the difference and connection between main chain and fragmentation chain
we have understood the types of fragmentation, so what's the difference between main chain and shard chain
turn left | turn right
the realization of Ethereum fragmentation is a long process. Even vitalik himself said that it will be graally realized by stages. We'd better look forward to whether fragmentation can move from theory to practice
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