Ruby Hash Each

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 ...

With the proliferation of data volume, Mysql+memcache has not met the needs of large-scale Internet applications, many organizations have chosen Redis as its architectural complement, however, redis the use of the threshold is not low, such as not supporting SQL, here for everyone to share the Redis use of the full raiders. Redis, one of the most closely watched NoSQL databases, has been used by many well-known internet companies, such as Sina Weibo, Pinterest and Viacom. However, being born with no support for SQL makes him look difficult ...

Now almost any application, such as a website, a web app and a mobile app, needs a picture display function, which is very important for the picture function from the bottom up. Must have a forward-looking planning picture server, picture upload and download speed is of crucial importance, of course, this is not to say that it is to engage in a very NB architecture, at least with some scalability and stability. Although all kinds of architecture design, I am here to talk about some of my personal ideas. For the picture server IO is undoubtedly the most serious resource consumption, for web applications need to picture service ...

In the past few years, relational databases have been the only choice for data persistence, and data workers are considering only filtering in these traditional databases, such as SQL Server, Oracle, or MySQL. Even make some default choices, such as using. NET will typically choose SQL Server, and Java may be biased toward Oracle,ruby, Mysql,python is PostgreSQL or MySQL, and so on. The reason is simple: In the past a long time, the relational database is robust ...

Hadoop version and Biosphere 1. 　　Hadoop version (1) The Apache Hadoop version introduces Apache's Open source project development process: Trunk Branch: New features are developed on the backbone branch (trunk). 　　Unique branch of attribute: Many new features are poorly stabilized or imperfect, and the branch is merged into the backbone branch after the unique specificity of these branches is perfect. Candidate Branch: Periodically split from the backbone branch, the general candidate Branch release, the branch will stop updating new features, if ...

(1) The Apache Hadoop version introduces Apache's Open source project development process:--Trunk Branch: New features are developed on the backbone branch (trunk); 　　-Unique branch of feature: Many new features are poorly stabilized or imperfect, and the branch is merged into the backbone branch after the unique specificity of these branches is perfect; --candidate Branch: Split regularly from the backbone branch, General candidate Branch release, the branch will stop updating new features, if the candidate branch has b ...

HBase terms in this article: column-oriented: Row column Group: Column families Column: Column unit: Cell Understanding HBase (an Open-source Google bigtable practical application) The biggest difficulty is what is HBase's data structure concept? First HBase is different from the general relational database, which is a database suitable for unstructured data storage. Another difference is that HBase is based on columns rather than on rows. Goo ...