Very powerful and scalable parallel SQL-based RDBMS systems have been commercially available for a long time. Also, I think that scalability concerns about ACID are exaggerated: ACID doesn't reach Facebook or Amazon scale, but there's only 5,000 or so sites that are that big.
A converse question to the one they ask is, "Why aren't web developers interested in Commercial Parallel RDBMS" and I think the answer to that is that there are a generation of us who grew up using open source databases, who find the thought of using a commercial database like sticking their hand in a toilet... Even if it's a reasonably priced product like SQL Server's Web Edition.
A lot of people see mysql and pgsql as going nowhere, so there's a lot of interest in something like mongodb which has a future.
Very powerful and scalable parallel SQL-based RDBMS systems have been commercially available for a long time. Also, I think that scalability concerns about ACID are exaggerated: ACID doesn't reach Facebook or Amazon scale, but there's only 5,000 or so sites that are that big.
A converse question to the one they ask is, "Why aren't web developers interested in Commercial Parallel RDBMS" and I think the answer to that is that there are a generation of us who grew up using open source databases, who find the thought of using a commercial database like sticking their hand in a toilet... Even if it's a reasonably priced product like SQL Server's Web Edition.
A lot of people see mysql and pgsql as going nowhere, so there's a lot of interest in something like mongodb which has a future.