I think the major feature from proprietary RDBMSes that you rarely see in OSS RDBMSes is workload management.
The ability to set CPU, RAM, disk and network quotas on queries or users is extremely useful and powerful. That capability by itself is pretty close to non-negotiable for any large line-of-business system.
I know there is something of an OSS RDBMS renaissance happening at the moment, but I haven't heard of any of them offering this, except for Greenplum ... which used to be proprietary.
Disclosure: I work for VMware, which sponsors Greenplum, so it makes sense for my awareness to be biased.
The ability to set CPU, RAM, disk and network quotas on queries or users is extremely useful and powerful. That capability by itself is pretty close to non-negotiable for any large line-of-business system.
I know there is something of an OSS RDBMS renaissance happening at the moment, but I haven't heard of any of them offering this, except for Greenplum ... which used to be proprietary.
Disclosure: I work for VMware, which sponsors Greenplum, so it makes sense for my awareness to be biased.