Why on earth would it be too late? MongoDB is comfortably in the top 3 in terms of traction and they just fixed what many consider the primary technical argument against using it. Too late for what?

MongoDB had a ton of momentum a few years ago but I think the argument being made is that it lost most of it due to the growing perception that it had fundamental design defects. Just anecdotally, a large number of companies I deal with had MongoDB at one time but I can't think of a one that uses it today. It was not replaced with a single thing but it was replaced for a variety of reasons.

As a long time observer of the database market with no skin in this particular game, in terms of regaining market momentum it is difficult to get past the reputation of being technically defective once that perception is broadly in place. To make matters worse, needing to completely replace the storage engine with a proper design will be viewed by some as an admission of that rather than an upgrade per se. It may be too little, too late for its long term prospects. By contrast, PostgreSQL is doing great right now; just about every company I talk to is using it somewhere.

Putting on my database engine designer hat, MongoDB did need to start from scratch with that storage engine; the original one was a naive design with a lot of problems. The sharding/replication design is still quite dodgy, which will hinder practical scalability. A new storage engine is a start but not enough if MongoDB wants to regain their momentum.

Here's my guess about some of the most utilized/popular databases:

* SQLite - it's everywhere thanks to mobile phones.

* Oracle.

* Microsoft's thing has to have a big following.

* Mysql.

* DB2 is not as big as Oracle, but IBM isn't some lightweight, either.

MongoDB gets talked about a lot, and probably used among people trying new stuff out, but I think a lot of mostly silent people wouldn't touch something like that for their important data with a 10 foot pole.

I think you overestimate the reach of Oracle. They are no where outside fortuine 500 and thats not a lot of deployments.

MySQL is most likely the most deployed thanks to the LAMP stack's proliferation across all sorts of small and medium sites. After that it really would be a toss up between MS-SQL who has traction in the SMB space due to it being used for sharepoint and exchange, and PostgreSQL

but lets be honest the most utilized database is Access.

I do a lot of work with geo-spatial analysis and often work with with various counties and municipalities in my experience everybody has an Oracle database stuffed away somewhere storing the regions canonical geo-spatial data.

Even if each town had an oracle database squirreled away ( which they don't ) That still would not even come close to just the wordpress deployments (60 Million).

Sadly many more people use Excel as their database when they should be using Access.

"Microsoft's thing"

SQL Server is definitely one of Microsoft's best products - as well as being an excellent database engine it also is used by SharePoint, the various Dynamics applications (CRM & ERP) as well as being the "natural" choice for application development in .Net

If I had to guess I would suspect that, at least in terms of revenue, SQL Server probably tops Oracle and DB2.

> SQLite - it's everywhere thanks to mobile phones.

and browsers...and tons of other pieces of software

MongoDB is placed 5th at DB-Engines, and I would suspect SQLite should actually be ranked higher since it used virtually everywhere.

http://db-engines.com/en/ranking

Cool site, and I like their methodology:

http://db-engines.com/en/ranking_definition

It's kind of how I did http://langpop.com/ back in the day (subsequently sold and it looks like they don't maintain it).

Reputation is hard to fix. Mysql today is still considered 'toy' db, even trough it is very stable and has good features. I think they lost industries with most money (financial and enterprise) to Cassandra and other competitors. Plus there are now solutions with aim to reimplement MongoDB API and be drop in replacement.

> Mysql today is still considered 'toy' db, even trough it is very stable and has good features.

I'd actually say that its feature set relative to other equally stable open-source DBs has gotten worse over the years, not better. Not because its gotten absolutely worse, but because other open source databases have gotten better faster.

Mysql has good selection of engines and good clustering.

I am generally curious about the source for your claim. Would you mind sharing, please?

Agreed