Auto-Increment Sequence MongoDB does not have out-of-the-box auto-increment functionality, like SQL databases. By default, it uses the 12-byte ObjectId for the _id field as the primary key to uniquely identify the documents. However, there may be scenarios where we may want the _id field to have some auto-incremented value other than the Read more…
Capped Collections MongoDB Capped collections are fixed-size circular collections that follow the insertion order to support high performance for create, read, and delete operations. By circular, it means that when the fixed size allocated to the collection is exhausted, it will start deleting the oldest document in the collection without providing Read more…
MongoDB – GridFS GridFS is the MongoDB specification for storing and retrieving large files such as images, audio files, video files, etc. It is kind of a file system to store files but its data is stored within MongoDB collections. GridFS has the capability to store files even greater than its Read more…
Working With rock MongoDB RockMongo is a MongoDB administration tool using which you can manage your server, databases, collections, documents, indexes, and a lot more. It provides a very user-friendly way for reading, writing, and creating documents. It is similar to PHPMyAdmin tool for PHP and MySQL. Downloading RockMongo You Read more…
Regular Expression-MongoDB Regular Expressions are frequently used in all languages to search for a pattern or word in any string. MongoDB also provides functionality of regular expression for string pattern matching using the $regex operator. MongoDB uses PCRE (Perl Compatible Regular Expression) as regular expression language. Unlike text search, we do not Read more…
Text Search-MongoDB Starting from version 2.4, MongoDB started supporting text indexes to search inside string content. The Text Search uses stemming techniques to look for specified words in the string fields by dropping stemming stop words like a, an, the, etc. At present, MongoDB supports around 15 languages. Enabling Text Search Initially, Text Search Read more…
MApReduce in MongoDB As per the MongoDB documentation, Map-reduce is a data processing paradigm for condensing large volumes of data into useful aggregated results. MongoDB uses mapReduce command for map-reduce operations. MapReduce is generally used for processing large data sets. MapReduce Command Following is the syntax of the basic mapReduce command − >db.collection.mapReduce( function() Read more…
ObjectId-MongoDB We have been using MongoDB Object Id in all the previous chapters. In this chapter, we will understand the structure of ObjectId. An ObjectId is a 12-byte BSON type having the following structure − The first 4 bytes representing the seconds since the unix epoch The next 3 bytes are the Read more…
Indexing Limitations Extra Overhead Every index occupies some space as well as causes an overhead on each insert, update and delete. So if you rarely use your collection for read operations, it makes sense not to use indexes. RAM Usage Since indexes are stored in RAM, you should make sure Read more…
Add Your Heading Text Here MongoDB uses ObjectIds as the default value of _id field of each document, which is generated while the creation of any document. The complex combination of ObjectId makes all the _id fields unique. Creating New ObjectId To generate a new ObjectId use the following code − >newObjectId Read more…