Last time I wrote about MongoDB for MySQL DBAs I described some of the basics of MongoDB querying, and this time I'll follow that up with some more on querying.

As we saw last time, the basic format of a MongoDB query is:
db.find(<query>,<attributes>)
Note that you do NOT replace db with the name of the database you want to query here, you just make the database you want to use the current one and issue the query, such as:
> use test
> db.mycoll.find()
The example above will find all objects in the mycoll collection, and will include all the object attributes and also the key (_id), like this:
{ "_id" : ObjectId("4eb0634807b16556bf46b214"), "c1" : 1 }
{ "_id" : ObjectId("4eb0634a07b16556bf46b215"), "c2" : 1 }
{ "_id" : …

Last time I wrote about MongoDB for MySQL DBAs I described some of the basics of MongoDB querying, and this time I'll follow that up with some more on querying.

As we saw last time, the basic format of a MongoDB query is:
db.find(,)
Note that you do NOT replace db with the name of the database you want to query here, you just make the database you want to use the current one and issue the query, such as:
> use test
> db.mycoll.find()
The example above will find all objects in the mycoll collection, and will include all the object attributes and also the key (_id), like this:
{ "_id" : ObjectId("4eb0634807b16556bf46b214"), "c1" : 1 }
{ "_id" : ObjectId("4eb0634a07b16556bf46b215"), "c2" : 1 }
{ "_id" : ObjectId("4eb0635607b16556bf46b216"), "c1" : 2, "c2" : 2 } …

In this second part of a series of blogs on using a NoSQL database, in this case MongoDB, aimed at MySQL users, I will describe querying a bit. And it's probably not what you expected if you haven't tried a NoSQL database or MongoDB more specifically, before. The first blogpost on this subject is here.

At the heart of accessing MongoDB is JavaScript, more specifically it uses the Mozilla SpiderMonkey JavaScript engine. As I wrote in the previous blog on this subject, JavScript is all over the place in MongoB, largely you can look at MonngoDB as JavaScript with HUGE space for variables, and although many would look at this as gross oversimplification, it works as simple descripton of …

I just finished reading a couple of interesting, and somewhat related, blog posts which I think are worth sharing (apologies to anyone who has already seen them). One is from Jelastic and the other is from Michal Hrušecký.

I’ve written about MariaDB and the Jelastic cloud before (see MariaDB now available as a hosted database via Jelastic cloud platform). Now Jelastic has published statistics on the relative popularity of the various databases they offer. The good news is MariaDB is currently the database of choice for 14% of their customers. The bad news is that we’re in fourth place behind their other three database choices (MySQL, …

As you probably know, I have been doing RDBMS work for many years, some 25+ years by now. At Recorded Future I am the database architect, and although an RDBMS is used extensively, MySQL in this case, we are looking at options, and are currently doing more and more work using a NoSQL Solution, probably te most popular one by now, namely MongoDB.

And before you complan: NoSQL is not a good term, but someone with a longer NoSQL background should then find something better, not yours truly. And for all intents and purposes, you know what I am talking about, right?

I plan to post a few MongoDB posts here, how it looks like from an RDBMS dudes (like myself) POV. This is the first installment, but there will be more. I should also point out that I am no expert in NoSQL technologies in general, nor specifically in MongoDB, but I am trying, and our MongoDB setup is large and complex enough to serve as a decent example: We have a …

Microsoft’s Android revenue. Tizen formation. And more.

# As Microsoft announced its latest Android-related patent agreement with Samsun, Goldman Sachs estimated that the company will make $444m in revenue from Android patent deals for fiscal year 2012.

# LiMo Foundation and The Linux Foundation announced the formation of Tizen to develop a Linux-based device software platform.

# Karmasphere raised $6m in a series B round …

Proof-of-concept Tungsten support for MongoDB arrived last May, when I posted about our hackathon effort to replicate from MySQL to MongoDB.  That code then lay fallow for a few months while we worked on other things like parallel replication, but the period of idleness has ended.  Earlier this week I checked in fixes to Tungsten Replicator to add one-line installation support for MongoDB slaves.

MySQL to MongoDB replication will be officially supported in the Tungsten Replicator 2.0.5 build, which will be available in a few weeks.  However, you can try out MySQL to MongoDB …

A special extended edition of Tech Messages for 2011-08-31 through 2011-09-21:

• Lab Overview
  This guy is serious about his lab!
• Throughput
  All sorts of useful information here. My favorite is the first table which includes bandwidth and packet throughput for different kids of circuits.
• Must see: 5 Steps to Scaling MongoDB (Or Any DB) in 8 Minutes
  These tips are relevant no matter what database system you are using.
• Understanding and …

Red Hat revenue up 28% in Q2. Funding for NoSQL vendors. And more.

# Red Hat reported net income of $40m in the second quarter on revenue up 28% to $281.3m.

# 10gen raised $20m in funding, while DataStax closed an $11m series B round, while also releasing its DataStax Enterprise and Community products. Additionally Neo Technology …

As Giuseppe Maxia recently posted we released Tungsten Replicator 2.0.4 this week.  It has a raft of bug fixes and new features of which one-line installations are the single biggest improvement.  I set up replicators dozens of times a day and having a single command for standard cluster topologies is a huge step forward.  Kudos to Jeff Mace for getting this nailed down.

So what's next?  You can get see what we are up to in general by looking at our issues list.  We cannot do everything at once, but here are the current priorities for Tungsten Replicator 2.0.5.

• Parallel replication speed and robustness. …