In the previous weeks, we started a series of blog posts that show you how we use “web scale” patterns to achieve scalability and flexibility in our back office software. The previous patterns discussed were Event Sourcing and CQRS. This week we will dive into mixed SQL – NoSQL. Showing you how this doesn’t just solve a technical problem, they help (more...)
MongoDB does have a query optimizer, and in most cases it's effective at picking the best of multiple possible plans. However it's worth remembering that in the case of the aggregate function the sequence in which various steps are executed is completely under your control. The optimizer won't reorder steps into the optimal sequence to get you out of trouble.
Optimizing the order of steps probably comes mainly to reducing the amount (more...)
Specialized graph databases such as Neo4J specialize in traversing graphs of relationships – such as those you might find in a social network. Many non-graph databases have been incorporating Graph Compute Engines to perform similar tasks. In the MongoDB 3.3 release, we now have the ability to perform simple graph traversal using the $graphLookup aggregation framework function. This will become a production feature in the 3.4 release.
The new feature (more...)
After a short introduction of the main business drivers behind the new architectures and the panel by Arun Gupta, it was time for Mano Marks (more...)
My latest book Next Generation Databases is now available to purchase! You can buy it from Amazon here, or directly from Apress here. The e-book versions are not quite ready but if you prefer the print version you’re good to go.
I wrote this book as an attempt to share what I’ve learned about non-relational databases in the last decade and position these in the context of the relational database landscape that (more...)
When I find myself making the same observation fairly frequently, that’s a good impetus to write a post based on it. And so this post is based on the thought that there are many analogies between:
- Oracle and the Oracle DBMS.
- IBM and the IBM mainframe.
And when you look at things that way, Oracle seems to be swimming against the tide.
Drilling down, there are basically three things that can seriously threaten Oracle’s market (more...)
Mike Stonebraker and Larry Ellison have numerous things in common. If nothing else:
- They’re both titanic figures in the database industry.
- They both gave me testimonials on the home page of my business website.
- They both have been known to use the present tense when the future tense would be more accurate.
I last wrote about Couchbase in November, 2012, around the time of Couchbase 2.0. One of the many new features I mentioned then was secondary indexing. Ravi Mayuram just checked in to tell me about Couchbase 4.0. One of the important new features he mentioned was what I think he said was Couchbase’s “first version” of secondary indexing. Obviously, I’m confused.
Now that you’re duly warned, let me remind you of aspects of (more...)
Once of the concepts I found difficult initially when looking at non-relational systems is the concept of the vector clock. Some databases – like Cassandra - use timestamps to work out which is the “latest” transaction. If there are two conflicting modifications to a column value, the one with the highest timestamp will be considered the most recent and the most correct.
Other Dynamo systems use a more complex mechanism known as a (more...)
Couchbase recently announced Non-first Normal Form Query Language (N1QL) – pronounced “Nickel” – a virtually complete SQL language implementation for use with document databases, and implemented within the Couchbase server 4.0.
I recently took a quick look.
Most of the examples use the sample films documents shown below (this is the same sample data we created for MongoDB in this post):
N1QL allows us to perform basic queries to retrieve selected documents (more...)
I’m taking a few weeks defocused from work, as a kind of grandpaternity leave. That said, the venue for my Dances of Infant Calming is a small-but-nice apartment in San Francisco, so a certain amount of thinking about tech industries is inevitable. I even found time last Tuesday to meet or speak with my clients at WibiData, MemSQL, Cloudera, Citus Data, and MongoDB. And thus:
1. I’ve been sloppy in my terminology around “geo-distribution”, in (more...)
Are you going to Oracle OpenWorld 2014? I am, and I hope to see you there! As you probably know, OpenWorld is a humongous event with tens of thousands of people in attendance and some amazing presentations. Why, I even hear Oracle’s new CTO might be there. I wonder if he has anything to talk about?
This year we’ll have a ton of activity at the Delphix booth. You can check out the speaking schedule, (more...)
This is a simple ADF application whose underlying business service implementation uses MongoDB for persistence.
The application allows create & update operations on a one-to-many data model (Department-Employees)
As shown in the screenshot below, you can (more...)