Mongodb Delete Data

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 ...

The initial key value comparison, MongoDB victory faster, and this has always been our goal to give the database system MySQL dragster the speed of the disk as its biggest obstacle, this really can make sense? Let's just make an obstacle, what about the solution? If an obstacle limits your dragster, you can choose to bypass it faster or improve on the computer. For example: Avoid the use of disk, as much as possible memory in lieu of faster disk (such as SSD) in fact, this is not good analogy, because the limit from the disk is like ...

We can see that the widely criticized global locks have been removed in this version, replaced by db-level locks, and collection-level locks are not far off. Here is a look at the 2.2 version of several new features: 1. Concurrency performance enhancements As mentioned above, http://www.aliyun.com/zixun/aggregation/13461.html ">mongodb In version 2.2 There is no longer a global lock over the entire daemon, but a lock ...

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 ({...).

Http://www.aliyun.com/zixun/aggregation/13461.html ">mongodb also has many areas to improve, such as global write locks (now just a database-level write lock). 　　This article focuses on how to scale to cope with large data, where the volume of large data is 100GB. It will be more meaningful when you look at the implementation of the underlying storage. Basically, MongoDB consists of a bunch of Bson document MMAP (Memory-mapped) lists, which ...

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"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 ...

With the rise of internet web2.0 websites, the relational database has become a very hot new field, the development of the non relational database products is very rapid. 　　But the traditional relational database in dealing with web2.0 website, especially the super large-scale and high concurrent SNS type web2.0 pure dynamic website already appeared to be powerless, has exposed many insurmountable problems, for example: 1, high configured--to the database higher concurrent reads and writes the demand WEB2.0 website to be based on user personalized information to generate real-time dynamic ...

Several years of work down, also used several kinds of database, accurate point is "database management system", relational database, there are nosql. Relational database: 1.MySQL: Open source, high performance, low cost, high reliability (these features tend to make him the preferred database for many companies and projects), for a large scale Web application, we are familiar with such as Wikipedia, Google, and Facebook are the use of MySQL. But the current Oracle takeover of MySQL may give us the prospect of using MySQL for free ...