Tim Kane <tim.kane@gmail.com> writes: > I've noticed a discrepancy in the return type for the gbt_cash_union > function... > On fresh instances of postgres 9.6.11, where the btree_gist extension is > newly created (version 1.2) yields a gbt_cash_union function with a return > type of gbtreekey16
... which is correct.
> While instances that have been upgraded from 9.6.2 to 9.6.11, where the > btree_gist was originally installed as 1.0 and then upgraded from 1.0 to > 1.2 - that same function has a return type of gbtreekey8
Hm. I think this is an oversight in commit 749a787c5; we were focused on fixing the functions' argument types and forgot that there were any return-type changes.
However, I'm not too fussed about it. Nothing checks those signatures at run-time, so it's basically cosmetic. The reason for the pushups in 749a787c5 was to ensure that we could name the functions in ALTER FUNCTION; but that just depends on the argument types, so it's not a reason to worry either.
> Is it safe/recommended to modify this function to return gbtreekey16?
I wouldn't sweat about it. If you did want to fix it, it'd have to be a manual UPDATE on pg_proc, there not being any ALTER FUNCTION way to do it. On the whole, the risk of fat-fingering the update and thereby hosing your database seems to outweigh any benefit.
> Perhaps safer still to drop the extension and recreate it?
That would force dropping the indexes that depend on it, so it seems like a big overreaction.
