Using hash to assign randomly, a given row can have the same origin when it is salted. Locally, this disperses the grip between RegionServers and allows prediction during read operations. The deterministic hash (deterministic hash) can reconstruct the complete row key on the client side, and can use the get operation to directly obtain the desired row. For example, after processing the above three row keys (unsalted), here we use the MD5 hash algorithm, and the results are as follows f18a79a8...

Using hash to assign randomly, a given row can have the same origin when it is salted. Locally, this disperses the grip between RegionServers and allows prediction during read operations. The deterministic hash (deterministic hash) can reconstruct the complete row key on the client side, and can use the get operation to directly obtain the desired row. For example, after processing the above three row keys (unsalted), here we use the MD5 hash algorithm, and the results are as follows f18a79a8...

HBase application scenarios are very extensive; there are a series of articles in front of the community. Everyone can take a look at the community; Zhang Shaohua this article mainly talks about the most important basic knowledge of HBASE, the involvement of rowkey, which is very awesome! Highly recommended!

HBase application scenarios are very extensive; there are a series of articles in front of the community. Everyone can take a look at the community; Zhang Shaohua this article mainly talks about the most important basic knowledge of HBASE, the involvement of rowkey, which is very awesome! Highly recommended!

设计，简约之路。

设计，简约之路。

To be honest, it is difficult to understand the seven principles of design patterns. In the study and application of design patterns, we often hear or see sentences such as "XXX pattern conforms to XXX principle" and "YYY pattern does not conform to YYY principle". . Therefore, in order to analyze the rationality of design patterns and improve our daily coding, it is very necessary to master and understand these seven principles.

To be honest, it is difficult to understand the seven principles of design patterns. In the study and application of design patterns, we often hear or see sentences such as "XXX pattern conforms to XXX principle" and "YYY pattern does not conform to YYY principle". . Therefore, in order to analyze the rationality of design patterns and improve our daily coding, it is very necessary to master and understand these seven principles.

The application of Salting in HBase is to assign a random character to each rowkey prefix, so that the data is scattered in multiple different regions to achieve a balanced load. If the table region in HBase is distinguished according to the prefix of each letter, let's compare the changes before and after adding salt to the rowkey. First, we give a set of rowkeys before salt: rk001 rk002 rk003 According to the partition, the above rowkey is in the same region. Below we add salt to the above ...

The application of Salting in HBase is to assign a random character to each rowkey prefix, so that the data is scattered in multiple different regions to achieve a balanced load. If the table region in HBase is distinguished according to the prefix of each letter, let's compare the changes before and after adding salt to the rowkey. First, we give a set of rowkeys before salt: rk001 rk002 rk003 According to the partition, the above rowkey is in the same region. Below we add salt to the above ...

Inheritance destroys packaging because inheritance exposes the details of the base class to the derived class. The internal details of the base class are usually visible to the subclass. This situation also illustrates the "white box fairy". An obvious problem is: the derived class inherits from the base class, if the implementation of the base class changes, it will affect the implementation of all derived classes; if the implementation inherited from the base class is the base class, it is ...

Inheritance destroys packaging because inheritance exposes the details of the base class to the derived class. The internal details of the base class are usually visible to the subclass. This situation also illustrates the "white box fairy". An obvious problem is: the derived class inherits from the base class, if the implementation of the base class changes, it will affect the implementation of all derived classes; if the implementation inherited from the base class is the base class, it is ...

Principle 1: Return to basic typesYou can tell many designers by checking their typography. Because this type is the basis of design. You can use types to create the entire design. You can also use the type design as a basis to get a subtle queue from the selected font. In order to improve the typography in the design, we must first learn the basics. Develop a vocabulary of description types. Understand terms such as tracking, kerning, and leading meaning. The article A Beautifully Illustrate...

Principle 1: Return to basic typesYou can tell many designers by checking their typography. Because this type is the basis of design. You can use types to create the entire design. You can also use the type design as a basis to get a subtle queue from the selected font. In order to improve the typography in the design, we must first learn the basics. Develop a vocabulary of description types. Understand terms such as tracking, kerning, and leading meaning. The article A Beautifully Illustrate...

HBase is playing an increasingly important role in real-time query due to its high performance in storage and reading and writing, but because it belongs to the NOSQL database type, it is not suitable for relational data. HBase query can only be queried by its rowkey (we can think of it as the unique index of the table in HBase). Therefore, the design of rowkey is particularly important in the design of using HBase. In addition, the design of rowkey is also related to the storage location of ...

HBase is playing an increasingly important role in real-time query due to its high performance in storage and reading and writing, but because it belongs to the NOSQL database type, it is not suitable for relational data. HBase query can only be queried by its rowkey (we can think of it as the unique index of the table in HBase). Therefore, the design of rowkey is particularly important in the design of using HBase. In addition, the design of rowkey is also related to the storage location of ...

The core concept of Dimit's Law is decoupling between classes, which reduces the coupling between classes. Only when the class is in a weakly coupled state, the reuse rate of the class will increase. The so-called reduction of inter-class coupling is actually to minimize the interaction between objects. If two objects do not have to communicate directly with each other, then the two objects should not have any direct interaction, if one of the objects needs to be called For a method of anothe...

The core concept of Dimit's Law is decoupling between classes, which reduces the coupling between classes. Only when the class is in a weakly coupled state, the reuse rate of the class will increase. The so-called reduction of inter-class coupling is actually to minimize the interaction between objects. If two objects do not have to communicate directly with each other, then the two objects should not have any direct interaction, if one of the objects needs to be called For a method of anothe...

Only talk to your immediate friends, the "friends" of an object include itself (this), the member objects it holds, the input objects, and the objects it creates. Try to publish as few public variables and methods as possible. Once the more properties and methods are public, the greater the scope of the modification. "It's your own". If a method is placed in this class without creating new inter-class dependencies or causing negative effects, then the sub-method should be placed in this class...

Only talk to your immediate friends, the "friends" of an object include itself (this), the member objects it holds, the input objects, and the objects it creates. Try to publish as few public variables and methods as possible. Once the more properties and methods are public, the greater the scope of the modification. "It's your own". If a method is placed in this class without creating new inter-class dependencies or causing negative effects, then the sub-method should be placed in this class...

The Law of Demeter (LOD), sometimes called the Least Knowledge Principle (LKP), is defined as: a software entity should interact with other entities as little as possible. Each software unit has minimal knowledge of other units, and is limited to those software units that are closely related to the unit. The original intention of Dimit's Law is to reduce the coupling between classes. Since each class minimizes its dependence on other classes, it is easy to make the functional modules of the s...

The Law of Demeter (LOD), sometimes called the Least Knowledge Principle (LKP), is defined as: a software entity should interact with other entities as little as possible. Each software unit has minimal knowledge of other units, and is limited to those software units that are closely related to the unit. The original intention of Dimit's Law is to reduce the coupling between classes. Since each class minimizes its dependence on other classes, it is easy to make the functional modules of the s...

Synthesis means a strong "ownership" relationship, which is generally expressed as a strict relationship between the whole and the part, and the life cycle of the part and the whole is the same

Synthesis means a strong "ownership" relationship, which is generally expressed as a strict relationship between the whole and the part, and the life cycle of the part and the whole is the same