When we shard a collection MongoDB distributes its data across all the shards of the cluster. MongoDB uses chunks, split and round balancing for getting it. For all of you who want to read about it here it is our last post MongoDB Pre-splitting. This is how MongoDB allows our […]
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Some days away since the MongoDB Workshop I made with the students (Bachelor and Master Degree) of the Escuela Superior de Ingenierías of the University of Huelva.
On April 22th, 2016 I will be at the Engineers School of the University of Huelva making a workshop about MongoDB.
Hi guys. You can now look at the material I used in the MongoDB presentation I did this morning for the future Informatic Engineers of the University of León. Hope you like! http://www.slideshare.net/juanroycouto/mongodb-basics-unileon
On Friday, December 4th 2015, I’ll be talking about MongoDB at the University of León, Spain.
This is the forth and last post of the serie about the MongoDB Aggregation Framework. We will continue with different queries. By the moment, we are going to use our five documents set inserted in our ‘aggfwktest’ collection. Average computation in a new field
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> db.aggfwktest.aggregate([ ... { $group : { _id : "$user_id", mediascore : { $avg : "$score" } } } ... ]) { "_id" : 3, "mediascore" : 7 } { "_id" : 2, "mediascore" : 6 } { "_id" : 1, "mediascore" : 7.5 } > |
The highest and the lowest, […]
Part III of the post MongoDB Aggregation Framework Examples After a brief and theoretical introduction to the Aggregation Framework philosophy, and its odds, we are going to begin with what is really important for us, the examples. Single purpose aggregation operations Count y Distinct are the operations we are most […]
Part II of the post MongoDB Aggregation Framework MongoDB vs SQL As I know that most of you come from SQL world, I am going to show the equivalence between the sql functions and the functions we will use with the aggregation framework. MongoDB Aggregation Operators SQL Functions $project SELECT […]
Today we begin a set of posts for understanding how to work with the Aggregation Framework. In my post First steps with MongoDB we could see how to make basic queries on the database. Therefore, this is the right moment to take a step forward and learn how to extract aggregated […]