Joe Conway <mail@joeconway.com> writes: > So you are proposing we add STATIC to VOLATILE/STABLE/IMMUTABLE (in the > third position before IMMUTABLE), give it IMMUTABLE semantics, mark > builtin functions that deserve it, and document with suitable caution > statements?
What is the point of that, exactly?
I'll agree that the user documentation could use some improvement in how it describes the volatility levels, but I do not see how it will reduce anybody's confusion to invent multiple aliases for what's effectively the same volatility level. Nor do I see a use-case for actually having multiple versions of "immutable". Once you've decided you can put something into an index, quibbling over just how immutable it is doesn't really change anything.
I'd teach pg_upgrade to inspect the post-upgraded catalog of is-use dependencies and report on any of these it finds and remind the DBA that this latent issue may exist in their system.
I agree the core behaviors of the system would remain unchanged and both modes would be handled identically. Though requiring superuser or a predefined role membership to actually use a "static" mode function in an index or generated expression would be an interesting option to consider.
