2 Byte Integer

Hadoop serialization and Writable Interface (i) introduced the Hadoop serialization, the Hadoop writable interface and how to customize your own writable class, and in this article we continue to introduce the Hadoop writable class, 　　This time we are concerned about the length of bytes occupied after the writable instance was serialized, and the composition of the sequence of bytes after the writable instance was serialized. Why to consider the byte length of the writable class large data program ...

1. Boxing, unpacking or aliases many of the introduction of C #. NET learning experience books on the introduction of the int-> Int32 is a boxing process, the reverse is the process of unpacking. This is true of many other variable types, such as short <-> int16,long <->int64. For the average programmer, it is not necessary to understand this process, because these boxes and unboxing actions can be automatically completed, do not need to write code to intervene. But we need to remember that ...

Here is a translation of the Redis Official document "A fifteen minute introduction to Redis data Types", as the title says, The purpose of this article is to allow a beginner to have an understanding of the Redis data structure through 15 minutes of simple learning. Redis is a kind of "key/value" type data distributed NoSQL database system, characterized by high-performance, persistent storage, to adapt to high concurrent application scenarios. It started late, developed rapidly, has been many ...

Base64 is one of the most commonly used encodings, such as the development of passing parameters, the <img/> tags in modern browsers to render pictures directly through Base64 strings, and for messages and so on.　　The BASE64 encoding is defined in RFC2045, which is defined as: Base64 content transfer encoding is designed to describe the 8-bit byte of any sequence as a form that is not easily recognized directly by the person. We know that any data is stored in binary form on the computer. One byte is 8 bits, one character is stored in the computer ...

This article is my second time reading Hadoop 0.20.2 notes, encountered many problems in the reading process, and ultimately through a variety of ways to solve most of the. 　　Hadoop the whole system is well designed, the source code is worth learning distributed students read, will be all notes one by one post, hope to facilitate reading Hadoop source code, less detours. 1 serialization core Technology The objectwritable in 0.20.2 version Hadoop supports the following types of data format serialization: Data type examples say ...

MapReduce is a programming model for parallel computing of large-scale data sets (greater than 1TB) to solve the computational problems of massive data.

<? php tutorial / ** * @ date 2010.12.21 * @ author Wang Gang * @ email 373882774@qq.c ...

In the case of Bitcoin transactions, blockchain trading is not a transaction in the usual sense of hand-delivering, but a transfer. If each transfer needs to construct a transaction data, it would be awkward.

This paper is an excerpt from the book "The Authoritative Guide to Hadoop", published by Tsinghua University Press, which is the author of Tom White, the School of Data Science and engineering, East China Normal University. This book begins with the origins of Hadoop, and integrates theory and practice to introduce Hadoop as an ideal tool for high-performance processing of massive datasets. The book consists of 16 chapters, 3 appendices, covering topics including: Haddoop;mapreduce;hadoop Distributed file system; Hadoop I/O, MapReduce application Open ...

Either in the pitiful free database space or large e-commerce sites, reasonable design table structure, make full use of space is very necessary. This requires that we have a full understanding of the commonly used MySQL data types for database systems. Now I will write down my little experience to share with you. The numeric type of the MySQL data type The numeric type is divided into three categories according to my classification: integer classes, decimal classes, and numeric classes. My so-called "digital class" refers to DECIMAL and NUMERIC, which are the same type. It is strictly speaking not ...