På lørdag 30. desember 2017 kl. 23:06:52, skrev Stephen Frost <sfrost@xxxxxxxxxxx>:
Greetings,
* Melvin Davidson (melvin6925@xxxxxxxxx) wrote:
> My query works as designed and has done so
> for two years. It shows the filenames for schemas and tables in the
> database.
I'm glad to hear that it works in your specific use-case.
Unfortunately, it doesn't work in the general case and therefore isn't a
good example. A proper query to return the filename for each user table
in the current database is:
SELECT
quote_ident(nsp.nspname) || '.' || quote_ident(c.relname),
s.setting || '/base/' || db.oid || '/' || c.relfilenode
FROM
pg_settings s
JOIN pg_database db on (s.name = 'data_directory')
JOIN pg_class c on (datname = current_database())
JOIN pg_namespace nsp on (c.relnamespace = nsp.oid)
WHERE
relfilenode <> 0
AND nsp.nspname !~ '^pg_'
AND nsp.nspname <> 'information_schema';
Note that, as discussed earlier in this thread, this doesn't actually
answer what Edson was asking for. Here's the query that would answer
his original request:
SELECT
quote_ident(nsp.nspname) || '.' || quote_ident(c.relname),
s.setting || '/base/' || db.oid || '/' || c.relfilenode,
(pg_stat_file(s.setting || '/base/' || db.oid || '/' || c.relfilenode)).size as size
FROM
pg_settings s
JOIN pg_database db on (s.name = 'data_directory')
JOIN pg_class c on (datname = current_database())
JOIN pg_namespace nsp on (c.relnamespace = nsp.oid)
WHERE
relfilenode <> 0
AND nsp.nspname !~ '^pg_'
AND nsp.nspname <> 'information_schema';
Technically speaking, while these queries are correct for PG10, in prior
versions of PostgreSQL it's possible to have user schemas that begin
with 'pg_' and therefore the filtering in the WHERE clause would have to
be more specific.
Note that both of these need to be run as a superuser in older versions
of PG. In PostgreSQL 10, a user could be GRANT'd 'pg_read_all_settings'
and be able to run the first query. We don't currently support being
able to GRANT a non-superuser the ability to run pg_stat_file(), but
that will likely be coming in PG 11.
Thanks!
That doesn't seem to work with custom types:
andreak@[local]:5433 10.1 andreak=# SELECT
quote_ident(nsp.nspname) || '.' || quote_ident(c.relname),
s.setting || '/base/' || db.oid || '/' || c.relfilenode,
(pg_stat_file(s.setting || '/base/' || db.oid || '/' || c.relfilenode)).size as size
FROM
pg_settings s
JOIN pg_database db on (s.name = 'data_directory')
JOIN pg_class c on (datname = current_database())
JOIN pg_namespace nsp on (c.relnamespace = nsp.oid)
WHERE
relfilenode <> 0
AND nsp.nspname !~ '^pg_'
AND nsp.nspname <> 'information_schema';
ERROR: could not stat file "/home/andreak/programs/postgresql-10/data/base/22039391/22039392": No such file or directory
quote_ident(nsp.nspname) || '.' || quote_ident(c.relname),
s.setting || '/base/' || db.oid || '/' || c.relfilenode,
(pg_stat_file(s.setting || '/base/' || db.oid || '/' || c.relfilenode)).size as size
FROM
pg_settings s
JOIN pg_database db on (s.name = 'data_directory')
JOIN pg_class c on (datname = current_database())
JOIN pg_namespace nsp on (c.relnamespace = nsp.oid)
WHERE
relfilenode <> 0
AND nsp.nspname !~ '^pg_'
AND nsp.nspname <> 'information_schema';
ERROR: could not stat file "/home/andreak/programs/postgresql-10/data/base/22039391/22039392": No such file or directory
│ public.biginttuple2 │ /home/andreak/programs/postgresql-10/data/base/22039391/22039392 │
--
Andreas Joseph Krogh
CTO / Partner - Visena AS
Mobile: +47 909 56 963
