MongoDB and Rockset link arms to figure out SQL-to-NoSQL application integration

MongoDB and fellow database biz Rockset have integrated products in a bid to make it easier to work with the NoSQL database through standard relational database query language SQL. The joint development is designed to make MongoDB – a NoSQL, document-oriented database – much more painless for developers to interrogate in …

[Pascal Monett]

"Rockset replicates MongoDB data and builds an external index"

So you're doing a Join in memory and writing it down in an "external index".

You're still doing a Join.

[dhruba]

Re: "Rockset replicates MongoDB data and builds an external index"

Rockset actually indexes every field in every document in the specified mongoDB collection. Rockset uses open source RocksDB to do this fast indexing. Rockset uses MongoDB's ChangeStream feature to continuously update the rockset-index in real time. Typicallly, there is a 1-to-1 mapping from a MongoDB collection and a Rockset collection.

Now, if your application makes a search query that does a lookup (e.g. find me docs where name=pascal') then it uses the Inverted Index in Rockset to find the appropriate record instantly and return it to the caller. If your application makes a query that needs to join and aggregate data from two different collections, then Rockset will use its ColumnarIndex to scan records and join them in real time and return it to the application.

The persistent external index does not automatilcally JOIN any collections

[Tim99]

I’ve posted this before

MongoDB gained popularity in the mid-2010s within web applications by helping to provide personalised content without developers worrying too much about database schema

This still applies (NSFW- YouTube): MongoDB is web scale Sigh. Just Learn SQL...

[a_yank_lurker]

Re: I’ve posted this before

The idea behind a dynamic schema in MongoDB is the schema can evolve more easily with time than is true of relational database. The real problem is not whether MongoDB or a relational db is better but using either in situations which play their strengths.