Обсуждение: [HACKERS] pg_get_object_address() doesn't support composites
See below. ISTM that pg_get_object_address should support everything
pg_identify_object_as_address can output, no?
I'm guessing the answer here is to have pg_identify_object_as_address
complain if you ask it for something that's not mapable.
> ~@decina.local/5621# CREATE TYPE comp AS (a int, b int);
> CREATE TYPE
> ~@decina.local/5621# select * from pg_identify_object_as_address(1259,'comp'::regclass, 0);
> type | object_names | object_args
> ----------------+---------------+-------------
> composite type | {public,comp} | {}
> (1 row)
>
> ~@decina.local/5621# select * from pg_get_object_address('composite type', '{public,comp}', '{}');
> ERROR: unsupported object type "composite type"
> ~@decina.local/5621#
--
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
Data in Trouble? Get it in Treble! http://BlueTreble.com
855-TREBLE2 (855-873-2532)
Jim Nasby wrote:
> See below. ISTM that pg_get_object_address should support everything
> pg_identify_object_as_address can output, no?
>
> I'm guessing the answer here is to have pg_identify_object_as_address
> complain if you ask it for something that's not mapable.
Yes, I think we should just reject the case in
pg_identify_object_as_address. Note that you can refer to the type
using it pg_type entry:
alvherre=# select * from pg_identify_object_as_address(1247,'comp'::regtype, 0); type │ object_names │ object_args
──────┼───────────────┼─────────────type │ {public.comp} │ {}
(1 fila)
alvherre=# select * from pg_get_object_address('type', '{public.comp}', '{}');classid │ objid │ subobjid
─────────┼───────┼────────── 1247 │ 16400 │ 0
(1 fila)
Trying to accept it using its pg_class entry would require adding an
OBJECT_COMPOSITE_TYPE member to the ObjectType enum. I considered it
back then, and eventually decided that it was not worth the trouble.
Another way to think about this problem is an approach Peter E suggested
not long ago, which was to change the objname/objargs representation
more completely.
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
On 2/17/17 9:53 PM, Alvaro Herrera wrote: > Another way to think about this problem is an approach Peter E suggested > not long ago, which was to change the objname/objargs representation > more completely. Hrm, I didn't see that. What was the idea? BTW, I do find it odd (and might eventually find it irritating) that some objname's squash schema and name into a single element. Not sure that's worth fixing at this point, though. -- Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX Experts in Analytics, Data Architecture and PostgreSQL Data in Trouble? Get it in Treble! http://BlueTreble.com 855-TREBLE2 (855-873-2532)
On 2/17/17 9:53 PM, Alvaro Herrera wrote: > Jim Nasby wrote: >> See below. ISTM that pg_get_object_address should support everything >> pg_identify_object_as_address can output, no? >> >> I'm guessing the answer here is to have pg_identify_object_as_address >> complain if you ask it for something that's not mapable. > Yes, I think we should just reject the case in > pg_identify_object_as_address. Attached patch does that, and tests for it. Note that there were some unsupported types that were not being tested before. I've added a comment requesting people update the test if they add more types. -- Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX Experts in Analytics, Data Architecture and PostgreSQL Data in Trouble? Get it in Treble! http://BlueTreble.com 855-TREBLE2 (855-873-2532) -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Вложения
On 2/18/17 4:26 PM, Jim Nasby wrote: > On 2/17/17 9:53 PM, Alvaro Herrera wrote: >> Jim Nasby wrote: >>> See below. ISTM that pg_get_object_address should support everything >>> pg_identify_object_as_address can output, no? >>> >>> I'm guessing the answer here is to have pg_identify_object_as_address >>> complain if you ask it for something that's not mapable. >> Yes, I think we should just reject the case in >> pg_identify_object_as_address. > > Attached patch does that, and tests for it. Note that there were some > unsupported types that were not being tested before. I've added a > comment requesting people update the test if they add more types. While testing a view on pg_depend, I discovered this has the unfortunate side-effect of meaning you can no longer use pg_identify_object_as_address against pg_depend.ref*. Using it against pg_depend was already problematic though, because it throws an error on the pinned objects if you try and hand it classid, objid or objsubid. So maybe it's OK. -- Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX Experts in Analytics, Data Architecture and PostgreSQL Data in Trouble? Get it in Treble! http://BlueTreble.com 855-TREBLE2 (855-873-2532)