On 19/11/2018 19:54, Alvaro Herrera wrote: > It's unclear why you made generated columns on partitions unsupported. > I'd fix the limitation if possible, but if not, at least document it.
This is explained here: + /* + * Generated columns in partition key expressions: + * + * - Stored generated columns cannot work: They are computed + * after BEFORE triggers, but partition routing is done + * before all triggers. + * + * - Virtual generated columns could work. But there is a + * problem when dropping such a table: Dropping a table + * calls relation_open(), which causes partition keys to be + * constructed for the partcache, but at that point the + * generation expression is already deleted (through + * dependencies), so this will fail. So if you remove the + * restriction below, things will appear to work, but you + * can't drop the table. :-( + */ > (I particularly notice that partition key is marked as unsupported in > the regression test. Consider partitioning on a SERIAL column, this is > clearly something that users will expect to work.) A serial column is not a generated column. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
