MongoDB

Replicaset+sharding Deployment: http://blog.csdn.net/lichangzai/article/details/50927588 MongoDB fragment Test 1. Connect to MONGOs to view system-related information Configsvr> Show DBS configsvr> use Config Configsvr> Show Collections Onfigsvr> Db.

(The following methods can only recover part of the data because the Oplog table does not have all of the synchronization logs saved, size limited) Because the Oplog table (called a table after collection for custom) has no index, I have to select

I. Environmental preparedness 1. This example uses 3 Linux hosts, with IP addresses as follows: Click (here) to collapse or open the Server a:192.168.1.231Server b:192.168.1.232Server c:192.168.1.2332. According to the need, open the

1. In fact, automatic lifting Vue, has been thinking about this problem, the problem is: Express backstage has a service is 3000 ports, and then VUE-CLI opened a 8080-port,So how do you combine the two of them? Do you want to cross the

Thod Nguyen, CTO of the EHarmony company, showed us a leap-forward in the user experience of the world's largest dating service site. After using the MongoDB technology, the pairing speed of eharmony is increased by 95% compared with the original

Robomongo,mongo Visualization Tools Wow, actually she is three (sinister face).You see, the interface is fresh, let people feel relaxed (shy), who still want to Win+r+mongo ah ah.Oh, yes, go on ... Say the right thing. In here ... Using SQL to

Mongmongo is a Java-written ODM framework, making the operation of MongoDB more convenient. Mongomongo strives to provide Java developers with an operational API similar to Activeorm or hibernate, and retains MongoDB's schemaless,document-based

Traditional relational databases are generally composed of three levels of databases (database), tables (table), records (record), and MongoDB are made up of three levels (db), Collections (collection), document objects (documents). MongoDB for

Http://itbilu.com/database/mongo/E1tWQz4_e.html Indexing is the most effective means to improve query query efficiency. An index is a special kind of data structure, indexes store part of the data in an easy to traverse form (such as a specific

Sometimes it is necessary to use multiple mongotemplate to access two different MongoDB instances, at which point the default configuration cannot be used (in spring-boot case) and can only be manually matched. 1. Introducing dependence (take spring-

MongoDB Master-slave copy/replica set/Shard cluster Introduction The previous article describes the installation of MongoDB, in MongoDB, there are two ways of data redundancy, one is Master-slave mode (master-slave replication), one is Replica sets

Let's say we have a MongoDB collection, Take this simple set as an example, we need to include how many different mobile phone numbers in the collection, the first thought is to use the DISTINCT keyword, Db.tokencaller.distinct (' Caller ').

1. IndexMost of MongoDB's indexes are built on Btree, and each collection can have up to 64 indexes1) Single-field index creationDb.user.createIndex ({age:1})//1 represents ascending, 1 means descendingDb.user.createIndex ({age:1},{"unique": true})//

Mongodb:nosql Database Important indicator points in MongoDB The three elements in MongoDB Database Collection Document The data store in MongoDB is stored in the form of Bson, and

Environment CentOS6.8 andmongodb4.0.11 Download MongoDB Package website address Switch to/USR/LOCAL/SRC directory [[email protected] src]# wget https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-rhel62-4.0.1.tgz2 Unpacking the

First, configure the MongoDB connection poolAttribute

Tag:table    Settings    create   doc   option     results    use    matching    delete    Query $filter = [' _id ' = = new Mongodb\bson\objectid ("$id"), ' creater_id ' = $user [' user_id '], ' delete_flag ' = ' N ',]; Query conditions

MongoDB High-availability cluster switching MongoDB's simplest cluster mode is the three-node replica set (replica set), which ensures that after a node failure, the remaining nodes can continue to provide services. In the MongoDB cluster,

Create a crawler project Doubanscrapy startproject douban Set the items.py file to store the data type and field names you want to save# -*- coding: utf-8 -*-import scrapyclass DoubanItem(scrapy.Item): title = scrapy.Field() # 内容 content =

1. Official Document: https://docs.mongodb.com/ecosystem/tools/hadoop/2.Hive Introduction:　　Hive Features:1.hive is a data warehouse, which relies on HDFS in comparison to data warehouses such as Oracle,mysql.2.hive is the SQL parsing engine that