mongodb unique index

Document directory 1. What is MongoDB? 3. MongoDB hands-on experience sharing 4. MongoDB and open-source projects 5. MongoDB client and tool set 7. MongoDB performance and Optimization 9. MongoDB news Address: http://blog.nosqlfan.com/html/

First, the index introductionIn MongoDB, indexes are used to support efficient queries. If there is no index, MONGODB must scan each document in the entire collection to find a matching document. However, if an appropriate index is established,

_ Id Index An index is automatically created for the _ id field for all sets except the set of capacity. This is a special index and cannot be deleted. The _ id index forces that its keywords are unique (except for some scenarios in the partition

Indexes can often greatly improve the efficiency of queries, and if there is no index, MongoDB must scan every file in the collection and select those records that meet the query criteria when reading the data. This scan full set of query efficiency

First, index MongoDB provides a variety of index support, indexed information is kept in system.indexes, and the default is always to create an index for _id, which uses the same relational database as MySQL. In fact, it can be said that the index

mongodb-sharding Deployment ScenariosFirst, Deployment Environment Five hosts: amongoshard01:10.212.74.43 amongoshard02:10.212.84.4 amongoshard03:10.212.98.23 amongoshard04:10.212.46.5 amongoshard05:10.212.

Original: MongoDB Data summaryThe previous Redis Data summary topic is very popular, here the MongoDB series of information is also a simple collation. Hope to be useful to everyone. Last update time: 2013-04-22What is 1.MongoDB? MongoDB

What is 1.MongoDB? MongoDB Introduction ppt Sharing MongoDB Gridfs Introduction ppt Two First knowledge of MongoDB Gridfs MongoDB Gridfs Introduction A NoSQL and MongoDB introduction ppt MongoDB: Next Generation MySQL?

Learning MongoDB 8: MongoDB index (index restrictions) (2), mongodb IndexI. Introduction In the previous article, we introduced basic index operations through db. collection. the createIndex (keys, options) syntax creates an index. We will continue

Previous wordsIndexes can often greatly improve the efficiency of queries, and if there is no index, MongoDB must scan every file in the collection and select those records that meet the query criteria when reading the data. This scan full set of