Re: table inheritance versus column compression and storage settings
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Eisentraut <peter@eisentraut.org>
Cc: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>,
pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2024-02-16T18:24:16Z
Lists: pgsql-hackers
I wrote:
> I find it surprising that the committed patch does not touch
> pg_dump. Is it really true that pg_dump dumps situations with
> differing compression/storage settings accurately already?
It's worse than I thought. Run "make installcheck" with
today's HEAD, then:
$ pg_dump -Fc regression >r.dump
$ createdb r2
$ pg_restore -d r2 r.dump
pg_restore: error: could not execute query: ERROR: column "a" inherits conflicting storage methods
HINT: To resolve the conflict, specify a storage method explicitly.
Command was: CREATE TABLE public.stchild4 (
a text
)
INHERITS (public.stparent1, public.stparent2);
ALTER TABLE ONLY public.stchild4 ALTER COLUMN a SET STORAGE MAIN;
pg_restore: error: could not execute query: ERROR: relation "public.stchild4" does not exist
Command was: ALTER TABLE public.stchild4 OWNER TO postgres;
pg_restore: error: could not execute query: ERROR: relation "public.stchild4" does not exist
Command was: COPY public.stchild4 (a) FROM stdin;
pg_restore: warning: errors ignored on restore: 3
What I'd intended to compare was the results of the query added to the
regression tests:
regression=# SELECT attrelid::regclass, attname, attstorage FROM pg_attribute
WHERE (attrelid::regclass::name like 'stparent%'
OR attrelid::regclass::name like 'stchild%')
and attname = 'a'
ORDER BY 1, 2;
attrelid | attname | attstorage
-----------+---------+------------
stparent1 | a | p
stparent2 | a | x
stchild1 | a | p
stchild3 | a | m
stchild4 | a | m
stchild5 | a | x
stchild6 | a | m
(7 rows)
r2=# SELECT attrelid::regclass, attname, attstorage FROM pg_attribute
WHERE (attrelid::regclass::name like 'stparent%'
OR attrelid::regclass::name like 'stchild%')
and attname = 'a'
ORDER BY 1, 2;
attrelid | attname | attstorage
-----------+---------+------------
stparent1 | a | p
stchild1 | a | p
stchild3 | a | m
stparent2 | a | x
stchild5 | a | p
stchild6 | a | m
(6 rows)
So not only does stchild4 fail to restore altogether, but stchild5
ends with the wrong attstorage.
This patch definitely needs more work.
regards, tom lane
Commits
-
Revert "Improve compression and storage support with inheritance"
- 74563f6b9021 17.0 landed
-
Improve compression and storage support with inheritance
- 0413a556990b 17.0 landed
-
Delay build of Memoize hash table until executor run
- 57f59396bb51 17.0 cited
-
Fix locking when fixing an incomplete split of a GIN internal page
- 6a1ea02c491d 17.0 cited