![]() ![]() Var MongoClient = require('mongodb'). In code and then update the scores array with the low homework pruned. Hint/spoiler: With the new schema, this problem is a lot harderĪnd that is sort of the point. Since there is a single document for each student containingĪn array of scores, you will need to update the scores array ![]() Remove the lowest homework score for each student. Write a program in the language of your choice that will the explain() command in the mongo shell prints information about how a query was done (e.g which index was used to find the data) But LyX tend to depend on TeX Live from Ubuntu repository, so I modified the last command to avoid apt from downloading gigabytes of out-dated texlive package: add-apt-repository ppa:lyx-devel/release apt-get update apt-get install -no-install-recommends lyx.An Index can be created (in the mongo shell) with the command ensureIndex: Multi key indexes – enables to find documents according to embedded data.This schema should be used also in “many to many” and “few to few” relationship. Recommended when there is “one to many” relationship and the data is too big to be embedded into one document. ![]() True linking – adding an _id field in a document, referring to another document.The key is to design the data structure so it would represent the common access patterns of the specific application, while avoiding duplication of data (because that could allow modification anomalies) Embedding relevant data into single document can improve performance and overcome the lack of transactions in mongodb.In this week we considered few aspects of database schema design in mongodb:
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