My mistake. I did some research and I found [this page](http://www.oehive.org/VersionHistory.html) which says that SQL-89 support was added in 1988, but SQL-92 support wasn't added until 2000.
But even so, SQL-89 is very anemic and not very expressive compared to SQL-92 (I'm thinking primarily of the support for different types of JOIN expressions), and the fact it took them 8 years to add SQL-92 support is telling (consider that MS Access 97 supported most of SQL-92). I can't find any information suggesting that Progress/OpenEdge implements later standards like SQL-1999 and SQL-2003 which add features I use on an almost daily-basis (recursive CTEs and window functions respectively).
> my point was it was direct and inline access to data
Doesn't that place architecture-based restrictions on performance though - how well does concurrency and transactions work in their OLTP model?
The ABL language supported functionality like that in the language for ages.
> Doesn't that place architecture-based restrictions on performance though - how well does concurrency and transactions work in their OLTP model?
By what metric?
No idea where you are getting that from, SQL has always been supported, but no reason why it should have been a priority given the vastly superior 4GL for creating applications against Progress until the 2000s.
database vendors like Oracle, Postgres, and other saw success in offering only a database product
Different companies, different priorities; Microsoft an obvious counter to that claim.
Comments on Linq, SQL etc; no, my point was it was direct and inline access to data. It was a very successful but niche approach that eventually got traction as a concept and alternative to SQL when tools like Linq arrived. But Progress devs had had that ease of data access in their programs for years, under the cover of the unfashionable 4GL label.
I agree with you on it's general awkwardness wrt industry trends, and obscure pricing and marketing strategies.