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