MongoDB

1. When a shard is unavailable, the entire sharding cluster is unavailable. Only the config database can read and write data, and data migration and chunks are stopped. For example, there are three shard in the cluster. Now I have stopped the

After reading the previous article, I believe everyone will know how to enable mongodb. This article details the addition, deletion, query, modification, and so on. First, when we open mongodb in the same way as the previous article, suddenly I was

Today, I will share with you some interesting things in mongodb, including aggregation and cursors. 1. Aggregation Common aggregate operations are the same as SQL server, including count, distinct, group, and mapReduce. count Count is the simplest,

1. This morning, a host setting part is localhost and another part is hostname, causing a failure to add shard to sharding. Special Records. Problem: each existing shard in a sharding is another mongod process on the local machine. When the shard

Another cluster exists in mongodb, which is the sharding technology. Similar to SQL server table partitions, we know that when the data volume reaches T level, our disks and memory We can't afford it. How can we deal with such a scenario.   I. Parts

First, I would like to thank cnblogs TV, the blogger TV, and friends who shared their support for the previous period. With your support, I was motivated to write down this issue. You may watch TV on the TV at night, or watch movies on the Internet.

Today, the wind is blowing outside. It is also a pleasure to write a blog in a warm hut. Well, let's talk a little bit about it. Today we will talk about how to connect to and operate mongodb using php. If you haven't followed the two phases, if you

@ Zheng summary creation date: 2013/1 problem occurrence environment: Nginx PHP 5.3.10 as php-fpm extension to nginx Mongodb-php-driver 1.2.12 Apsaradb for MongoDB 2.2 This problem is caused by official features of MongoDB PHP Driver 1.2.x. For

I have extracted and sorted out ten key points that will help you with mongodb's phased technical summary: 1. mongodb table names and field names should all use lower-case lettersMongodb is case-sensitive by default. To avoid frequent program access

Copy codeThe Code is as follows: // Initialize gridfs $ Conn = new Mongo (); // connect to MongoDB $ Db = $ conn-> photos; // select a database $ Grid = $ db-> getGridFS (); // get the gridfs object // There are three methods for storing files

Copy codeThe Code is as follows: // The delimiter string is $ Querys = array ("name" => "shian "); // Number of equal values$ Querys = array ("number" => 7 ); // How much is the data size?$ Querys = array ("number" => array ('$ gt' => 5 )); // The

MongoDb is one of the good NoSQL databases. NoSQL means Not Only SQL, which is easier to expand than relational databases such as MySQL and SQL Server, and more suitable for storing massive data, data can be elastically scalable across LAN and WAN,

MongoDB has been in use for a long time, And MongoDB-based data storage has never been used for permission access (MongoDB is set to have no permission access restrictions by default). Today I have spent some time studying it, the research results

Our php mongodb can also provide almost all functions that mysql and SQL server can do. This article will introduce in detail I. Operators Operators are certainly known to all. They are equal to, greater than, less than, not equal to, greater than

The code is roughly as follows: Copy codeThe Code is as follows: Function generate_auto_increment_id ($ namespace, array $ option = array ()) { $ Option + = array ( 'Init '=> 1, 'Step' => 1, ); $ Instance = new Mongo (); $ Instance = $ instance->

The db2 tutorial is: Basic Performance adjustment of IBM DB2. Buffer PoolIf you have experience using DB2 UDB, you should know that the buffer pool is the space allocated separately to the DB2 database manager in the memory, let it add new data as a

The db2 tutorial is: DB2 UDB V8.1 management learning notes (1 ). Basic concepts of DB2Several Concepts from top to bottom in DB2:Instance ),Database ),Table space ),Container)In an operating system, DB2 data service can run multiple instances at

The db2 tutorial is: submit SQL statement (to) 3 using a form. List D: the final version of the buildSQLInsert function.Function buildSQLInsert (targetTable, omitFields)IStr = "insert into" & targetTable &""VStr = "values ("NStr = "("Loop in the

The current db2 tutorial is: DB2 9 (Viper) Quick Start. To help you quickly master the XML features of DB2, complete several common tasks, such: Create a database object for managing XML data, including a test database, sample tables, and views.

1. Search for the employee's number, name, department, and date of birth. If the date of birth is null, the date is displayed as unknown and is sorted by department. The date format is yyyy-mm-dd.Copy codeThe Code is as follows:Select emp_no,