MongoDB Aggregation Concepts

MongoDB provides the three approaches to aggregation, each with its own strengths and purposes for a given situation. This section describes these approaches and also describes behaviors and limitations specific to each approach. See also the chart that compares the…

password option file in MongoDB

if you’re curious to know whether we’ve password option file concept in MongoDB something similar to MySQL (refer below links). http://dev.mysql.com/doc/refman/5.1/en/password-security-user.html http://stackoverflow.com/questions/16299603/mysql-utilities-my-cnf-option-file With this, we can actually save credentials in a option hidden file within client session and we no…

NUMA (Non Uniform Memory Access) for MongoDB

We usually did see some performance boost when NUMA was disabled using -> numactl –interleave=all ….. Below are the details from MongoDB http://docs.mongodb.org/manual/administration/production-notes/ Running MongoDB on a system with Non-Uniform Access Memory (NUMA) can cause a number of operational problems,…

MongoDB Queries

–> To find documents in a collection we have syntax db.<collection Name>.find(); –> db.books.find(); — it will provide all documents in collection books. It actually returns a cursor. –> To make the output look a bit pretty we have following…

MongoDB Authentication

[root@my-host-name bin]$ cat /etc/mongod.conf # MongoDB Configuration File # # General Settings journal = true fork = true quiet = true directoryperdb = true smallfiles = true # Logging verbose = true logappend = true oplogSize = 50 #logpath =…

MongoDB Diagnostic Tools/Utilities

MongoDb Inc. currently don’t have one-tool-for-any-troubleshooting-scenario. However, they have a number of tools that help with different aspects of trouble shooting. The best practice is (like in many other Monitoring/Troubleshooting apps) to have a holistic (NOC) view on overall system…

MongoDB Export cmd

Here’s is a simple MongoDB ‘mongoexport’ command syntax to backup the document/database. This command can be used to backup based on particular conditions (‘where’ clause) Go to MongoDB bin  directory and execute as below:./mongoexport –host localhost –port 10000 -d doc_name…

MongoDB vs MySQL

Here is a comparison between MongoDB and Relational database, MySQL:   Because of distributed key value store, MapReduce calculation capability and document oriented NoSQL features, MongoDB® is The database for Big Data processing.