Thread: btree_gist extension - gbt_cash_union return type
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
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
I expect something is missing from the extension upgrade script to modify the return type.
Is it safe/recommended to modify this function to return gbtreekey16?
Perhaps safer still to drop the extension and recreate it?
Thanks in advance. If this should be considered a bug, and there is a better place to report such - please advise.
Tim
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.
regards, tom lane
Thank you Tom, I appreciate the thorough explanation.
Good to confirm that it’s of no consequence.
Tim
On Fri, 22 May 2020 at 15:44, Tom Lane <tgl@sss.pgh.pa.us> wrote:
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.
regards, tom lane