Peter Eisentraut wrote:
Another point, as there appear to be diverging camps about supertransactional stored procedures vs. autonomous transactions, what would be the actual use cases of any of these features? Let's collect some, so we can think of ways to make them work.
An analogy I like to use for a very capable DBMS is that of an operating system, and each autonomous transaction is like a distinct process/thread in this system. The DBMS is like a virtual machine in which processes/autonomous transactions run.
Like with an operating system, a process/auto-transaction can be started by another one, or by the OS/DBMS (or a root process/auto), and once running all processes are mutually independent to a large extent, in that each has its own separatable privileges or state or view of the database, the database being an analogy to the file system.
A process/auto-transaction can be started by a DBMS client, analogous to a user, but it doesn't have to be. The message passing feature that Pg has, listen/notify, is like inter-process communication between these processes/autos.
A stored procedure always runs within the context of one process/auto, and a regular transaction or savepoint or whatever is specific to a process/auto.
Has anyone else thought of the DBMS as operating system analogy? I don't recall specifically reading this anywhere, but expect the thought may be common.
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