No. CouchDB uses an “optimistic concurrency” model. In the simplest terms, this just means that you send a document version along with your update, and CouchDB rejects the change if the current document version doesn’t match what you’ve sent. It’s deceptively simple, really. You can reframe many normal transaction based scenarios for CouchDB. You do … Read more
@Schildmeijer is largely right, however port 7001 is still used when using TLS Encrypted Internode communication So my complete list would be for current versions of Cassandra: 7199 – JMX (was 8080 pre Cassandra 0.8.xx) 7000 – Internode communication (not used if TLS enabled) 7001 – TLS Internode communication (used if TLS enabled) 9160 – … Read more
I’ve only just started with non-relational DBs, and I am still trying to wrap my head around it and figure out what the best model would be. And I can only speak for CouchDB. Still, I have some preliminary conclusions: Have you come up with alternate designs that work much better in the non-relational world? … Read more
Just promise yourself that you will never try to map a relational data model to a NoSQL database like MongoDB or CouchDB… This is the most common mistake developers make when evaluating emerging tech. That approach is analogous to taking a car and trying to use it to pull your cart down the road like … Read more
You can use below aggregation with mongodb 3.6 and above db.resources.aggregate([ { “$match”: { “type”: “FUNC” } }, { “$lookup”: { “from”: “initiatives”, “let”: { “id”: “$_id” }, “pipeline”: [ { “$match”: { “$expr”: { “$in”: [“$$id”, “$ressources.function”] } } }, { “$unwind”: “$ressources” }, { “$match”: { “$expr”: { “$eq”: [“$ressources.function”, “$$id”] } } … Read more
Don’t use insert. Use update with upsert=true. Update will look for the document that matches your query, then it will modify the fields you want and then, you can tell it upsert:True if you want to insert if no document matches your query. db.collection.update( <query>, <update>, { upsert: <boolean>, multi: <boolean>, writeConcern: <document> } ) … Read more
You need to think of how you approach the application in a document oriented way. If you simply try to replicate how you would model the problem in an RDBMS then you will fail. There are also different trade-offs that you might want to make. ([ed: not sure how this ties into the argument but:] … Read more
Definitely Relational. Unlimited flexibility and expansion. Two corrections, both in concept and application, followed by an elevation. Correction It is not “filtering out the un-needed data”; it is selecting only the needed data. Yes, of course, if you have an Index to support the columns identified in the WHERE clause, it is very fast, and … Read more
This is a great question, something I have pondered over quite a bit. I will summarize my lessons learned: You can easily use Lucene/Solr in lieu of MongoDB for pretty much all situations, but not vice versa. Grant Ingersoll’s post sums it up here. MongoDB etc. seem to serve a purpose where there is no … Read more
I think there are some essential differences between CouchDB and Couchbase Server that need to be pointed out. I will not write about the advantages of switching from CouchDB to the Couchbase Server because those are described pretty much everywhere (see The Future of CouchDB by Damien Katz or Couchbase vs. Apache CouchDB by Couchbase). … Read more