"Daniel Verite" <dan...@manitou-mail.org> writes: > I notice that in the commited patch, you added the ability > for DeleteVariable() to reject the deletion if the hook > disagrees.
Right. > But this can't happen in practice because as mentioned just upthread > the hook called with NULL doesn't know if the variable is getting unset > or initialized, so rejecting on NULL is not an option. It would have required the caller to set a value before installing the hook, which would require some reshuffling of responsibility. In the draft patch I sent a little bit ago, this is handled by installing a "substitution hook" first, and that hook transmogrifies NULL into an allowed setting. That gets to the same place in a slightly different way, but it also covers allowing "\unset FOO", which inserting initial values wouldn't. > Attached is a proposed patch to add initial values to > SetVariableAssignHook() to solve this problem, and an example for > \unset AUTOCOMMIT being denied by the hook. I think disallowing \unset is a nonstarter on compatibility grounds. We should allow \unset but treat it like setting to "off" (or whatever the default value is). regards, tom lane -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers