Re: How to determine database market share?

Some interesting points. Interesting that there is a parallel thread on what's the difference between RDBMS and DBMS.

If someone asks about database marketshare than I'd think that all systems which comply with base requirements (e.g. ACID) must be counted. Whether it's IMS, a multi-valued DBMS, an XML database, ODBMS or RDMS doesn't matter.
One gets what one asks for.
Some competitors have gone as far as distinguishing between RDBMS and "modern" RDBMS. Whatever that means...
IMHO opinion the concept of RDBMS is too limiting these days as we see big vendors turning their products into ORDBMS which are becoming hybrids including XQuery and native XML types.

Cheers
Serge

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Serge Rielau
DB2 SQL Compiler Development
IBM Toronto Lab