Mongodb Related Documents

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 ({...).

In mailbox rapid expansion process, one of the performance problems is the MongoDB database level write lock, the time spent in the lock waiting process, directly reflects the user's use of the service process delay. To address this long-standing problem, we decided to migrate a common set of MongoDB (storing mail-related data) to a separate cluster. According to our inference, this will reduce the lock latency by 50%, and we can add more fragments, and we expect to be able to optimize and manage different types of data independently. We start from Mon ...

MongoDB in the latest version of the 2.4 User Rights Management made a new adjustment, the permissions are refined, enhanced security, more and more like the permissions of MySQL management. 2.4 Before the version of User Management 1, the creation of a database management user 1.1, access to the WEIW database: >use weiw; 1.2, add users (Read and write permissions, Readonly-->false): >db.adduser ("java", "Ja ...)

"Editor's note" This blog author Luke Lovett is the MongoDB company's Java engineer, he demonstrated MONGO connector after 2 years of development after the metamorphosis-complete connector at both ends of the synchronization update. , Luke also shows how to implement fuzzy matching by Elasticsearch. The following is a translation: the introduction assumes that you are running MongoDB. Great, now that you have an exact match for all the queries that are based on the database. Now, imagine that you're building a text search work in your application ...

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 ...

"Editor's note" The Hot market for SaaS investment has spawned a large number of startups, and many startups in the 2014 SaaS niche have received huge sums of money, which will provide them with strong support for future platforms, marketing and so on. Enterprise cloud applications, represented by SaaS, are changing the overall it landscape. SaaS services are popular with small and medium-sized enterprises because of their simplicity and ease of use, as well as various features and user-friendly SaaS applications, and for the performance of the SaaS industry, IT staff in all walks of life ...

The appearance of MapReduce is to break through the limitations of the database. Tools such as Giraph, Hama and Impala are designed to break through the limits of MapReduce. 　　While the operation of the above scenarios is based on Hadoop, graphics, documents, columns, and other NoSQL databases are also an integral part of large data. 　　Which large data tool meets your needs? The problem is really not easy to answer in the context of the rapid growth in the number of solutions available today. Apache Hado ...

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 ...

Introduction with the advent of the cloud computing era, various types of Internet applications are emerging, the relevant data model, distributed architecture, data storage and other database related technical indicators also put forward new requirements. Although the traditional relational database has occupied the unshakable position in the data storage, but because of its inherent limitation, has been unable to satisfy the cloud computing age to the data expansion, reads and writes the speed, the support capacity as well as the construction and the operation cost request. The era of cloud computing has put forward a new demand for database technology, which is mainly manifested in the following aspects. Mass data processing: to ...

"IT168" I have always felt that nosql in fact very easy to understand, I have also had a very in-depth study of NoSQL, but in the recent preparation of yuntable chart, found that NoSQL not only very profound, 　　And my personal understanding of NoSQL is only superficial, but I am still a "shame and then Yong" people, so after a period of study, from the sixth part of this series, will talk to you nosql, and this article will be the main to do a NoSQL database review. ...