Group By In Mongodb

Recently MongoDB in hack news is frequently shot. Many people even claim to hate Mongodb,david Mytton on his blog to expose MongoDB many existing problems. But those who hate have a lot in common, as a comeback: Russell Smith brings a summary of years of work experience. Russell Smith has worked as an OPS and a large website scaling advisor and has helped Guardian, Experian and many other companies, MongoDB Lond ...

MongoDB is currently the best document-oriented free Open-source NoSQL database. If you are preparing to participate in a technical interview for the MongoDB NoSQL database, you might want to look at the following MongoDB NoSQL interview questions and answers. These MongoDB NoSQL interview questions cover the basic concepts of NoSQL databases, replication (Replication), fragmentation (Sharding), Transactions and locks, trace analysis Tools (Profiler), nuances, and logging features. Let's look at the following ...

A few days ago on the hacknew appeared an article, the title is very sturdy, called "Don" T use http://www.aliyun.com/zixun/aggregation/13461.html ">mongodb", Its content is also directly expressed dissatisfaction with the MongoDB, the author enumerated the MongoDB in the use of various problems encountered. Even rise to the challenge of their development team, saying they may only care about benchmark data, not the number of users ...

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 ({...).

To ease restrictions on the organization's large data services, Red Hat integrates 10gen MongoDB data into its new Identity Management Pack Rhel suite. 10gen Product Marketing Director Kellystirman that "a more robust identity management system it has a central infrastructure through which companies can be used for identity management in many different types of applications." "With the unification of MongoDB and Red Hat authentication management systems, stores that already use Rhel will be easier to build and run using Mon ...

MongoDB released the 1.6.0 version, which is the fourth major stable version of the 1.0,1.2,1.4 version, and released the 1.6.1 release on August 17. This release focuses on enhanced dynamic expansion (Scale-out) features, http://www.aliyun.com/zixun/aggregation/14273.html ">sharding functionality is already available in the production environment." Use both horizontal and replication collections (replica sets ...).

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 ...)

Hot week: Don't blame open source technology it's innocent. Posted 23 hours ago | Times Read | SOURCE csdn| 0 Reviews | Author Wang Cloud hotspot open source Google Amazon IBM Transistor MongoDB Summary: This week's content: Open source technology is important, please do not give it for security problems, for the load after the 42 "monster" level problem, how should we solve? Google GCE vs. Amazon EC2, who is stronger, and Google and other Internet companies will become innovation centers? Four misunderstandings and four conjectures based on IaaS;

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 ...

Absrtact: Paytm was invested by Alibaba $575 million, valued at $2 billion Paytm by Alibaba Group and its financial services subsidiary Ant Micro Financial Services group to invest about 575 million U.S. dollars. It is understood that after the completion of the transaction, Alibaba and Ant finance will hold one, Paytm Alibaba 575 million dollar investment, the valuation of more than 2 billion U.S. dollars Paytm by the Alibaba Group and its financial services subsidiary Ant Micro Financial Services group to invest about 575 million U.S. dollars. It is understood that after the completion of the transaction, Alibaba and ...