Re: support fast default for domain with constraints - Mailing list pgsql-hackers

I’ve been burned my this issue in the past so would be great if this could get in.

+/*
+ * DomainHasVolatileConstraints --- check if a domain has constraints with
+ * volatile expressions
+ *
+ * Returns true if the domain has any constraints at all. If have_volatile
+ * is not NULL, also checks whether any CHECK constraint contains a volatile
+ * expression and sets *have_volatile accordingly.
+ *
+ * The caller must initialize *have_volatile before calling (typically to
+ * false). This function only ever sets it to true, never to false.
+ *
+ * This is defined to return false, not fail, if type is not a domain.
+ */
+bool
+DomainHasVolatileConstraints(Oid type_id, bool *have_volatile)

Call it CheckDomainConstraints or something instead? IMO it's confusing
the have it not return what it's called.

Also, it'd make it more self-contained and thus safer to initialise have_volatile to false.

+ if (typentry->domainData != NULL)
+ {
+ if (have_volatile)
+ {
+ foreach_node(DomainConstraintState, constrstate,
+ typentry->domainData->constraints)
+ {
+ if (constrstate->constrainttype == DOM_CONSTRAINT_CHECK &&
+ contain_volatile_functions((Node *) constrstate->check_expr))
+ {
+ *have_volatile = true;
+ break;
+ }
+ }
+ }
+
+ return true;
+ }
+
+ return false;
+}
Could simplify the code by doing an early return if domainData == NULL?
(same with have_volatile below)