Piotr Findeisen <piotr.findeisen@xxxxxxxxxxxxxxxxx> writes: > Internally, array types get a name in the form of `_<typename>`. Typically, yes. > *Can a user use `_<typename>` to define a column of array type?* Sure ... didn't you try it? > *Is it supported?* Not really, because it's not guaranteed that the name looks like that. There are various corner cases where something else would be generated, either to avoid a collision, or because truncation is needed. However, if you've taken the trouble to check what name actually got assigned to the array type, it's perfectly valid to use that name. > The reason I am asking is that e.g. int4[] and _int4 behave differently. > Although they look the same, the have different pg_attribute.attndims. Yeah. Nothing really cares about attndims though ... it's vestigial. Perhaps we should remove it someday. regards, tom lane
