Mongodb List Documents In Collection

MongoDB company formerly known as 10gen, founded in 2007, in 2013 received a sum of 231 million U.S. dollars in financing, the company's market value has been increased to 1 billion U.S. dollar level, this height is well-known open source company Red Hat (founded in 1993) 20 's struggle results. High-performance, easy to expand has been the foothold of the MongoDB, while the specification of documents and interfaces to make it more popular with users, this point from the analysis of the results of Db-engines's score is not difficult to see-just 1 years, MongoDB finished the 7th ...

1.count Count returns the number of documents in the collection &http://www.aliyun.com/zixun/aggregation/37954.html ">nbsp;db.refactor.count () No matter how large the collection is, the number of documents can be returned quickly. You can pass the query, MongoDB calculates the number of query results Db.refactor.count ({...).

1: A simple introduction MongoDB is a distributed document database, supporting the master-slave structure of similar closed-type database, the document is stored in binary http://www.aliyun.com/zixun/aggregation/16702.html ">json form", No locks, no transactions, indexed. 2: Installation Steps Step one: Download the assembly http://www.mongodb.org/downloads Part II: Extract and extract the relevant bin directory to C ...

NoSQL Recent momentum is good, http://www.aliyun.com/zixun/aggregation/13461.html ">mongodb is one of the Jiao jiao, oneself learn nosql when also reference a lot of information, The final decision to start from the MongoDB, the most important reason has two: 1 oneself is a simple amateur, all problems I think whether there is a simple way to solve, rather stop to think a lot of time, also do not want to use stupid method to do immediately, and Mong ...

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 ...

It was easy to choose a database two or three years ago. Well-funded companies will choose Oracle databases, and companies that use Microsoft products are usually SQL Server, while budget-less companies will choose MySQL. Now, however, the situation is much different. In the last two or three years, many companies have launched their own Open-source projects to store information. In many cases, these projects discard traditional relational database guidelines. Many people refer to these items as NoSQL, the abbreviation for "not only SQL." Although some NoSQL number ...

There are a few things to explain about prismatic first. Their entrepreneurial team is small, consisting of just 4 computer scientists, three of them young Stanford and Dr. Berkeley. They are using wisdom to solve the problem of information overload, but these PhDs also act as programmers: developing Web sites, iOS programs, large data, and background programs for machine learning needs. The bright spot of the prismatic system architecture is to solve the problem of social media streaming in real time with machine learning. Because of the trade secret reason, he did not disclose their machine ...

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 ...

Large data processing technology is changing the current operating mode of the computer. We've got a lot of revenue from that because it's the big data processing technology that brings us search engine Google. 　　But the story is just beginning, and for several reasons, we say that large data processing technology is changing the world: * It can handle almost every type of data, whether it's microblogging, articles, emails, documents, audio, video, or other forms of data. 　　* It works very fast: practically in real time. * It's universal: because it's ...

New Year's atmosphere, many people have embarked on a journey of life. It is rumored that a computer doctor at the Chinese Academy of Sciences also disillusioned at the beginning of the new year-to join the Beijing Longquan Temple and become an ascetic monk. Online Hot Biography said: "A PhD in the Chinese Academy of Sciences, and finally saved enough paper, the results of the tutor monk ... No one knows where the mentor is now, but occasionally returns one or two emails. He e-mailed, "teacher, I want to reply." 　　Mentor back, donor, do not be too persistent, reply not to reply, in fact, are empty ... Many times to the reporter to Longquan Temple and interviewed the temple of a number of mages and home ...