Get table and column "owning" a sequence - postgresql

Question

I can run the following line:
ALTER SEQUENCE seqName OWNED BY table.id;
How can I get the 'owner' set by OWNED BY for a sequence (in this case: table.id)?

Answer 1

You may use following query:
select s.relname as seq, n.nspname as sch, t.relname as tab, a.attname as col
from pg_class s
join pg_depend d on d.objid=s.oid and d.classid='pg_class'::regclass and d.refclassid='pg_class'::regclass
join pg_class t on t.oid=d.refobjid
join pg_namespace n on n.oid=t.relnamespace
join pg_attribute a on a.attrelid=t.oid and a.attnum=d.refobjsubid
where s.relkind='S' and d.deptype='a'
It returns all sequences with owner information. Just filter them in WHERE clause and that's it.

Answer 2

Get the "owning" table and column
ALTER SEQUENCE seqName OWNED BY table.id;
Your ALTER SEQUENCE statement causes an entry in the system catalog pg_depend with the dependency type (deptype) 'a' and a refobjsubid greater than 0, pointing to the attribute number (attnum) in pg_attribute. With that knowledge you can devise a simple query:
SELECT d.refobjid::regclass, a.attname
FROM pg_depend d
JOIN pg_attribute a ON a.attrelid = d.refobjid
AND a.attnum = d.refobjsubid
WHERE d.objid = 'public."seqName"'::regclass -- your sequence here
AND d.refobjsubid > 0
AND d.classid = 'pg_class'::regclass;
Double quotes ("") are only needed for otherwise illegal names (mixed case, reserved words, ...).
No need to assert that refclassid is of type regclass since the join to pg_attribute does that automatically.
No need to assert that the sequence is a sequence since schema-qualified object names are unique across the database.
No need to join to pg_class or pg_namespace at all.
The schema name is only needed to disambiguate or if it's not in the search_path.
The same table name (or sequence name for that matter) can be used in multiple schemas. A cast to the object identifier type regclass observes the current search_path to pick the best match if you omit the schema qualification. If the table is not visible, you get an error message.
What's more, a regclass type is displayed as text to the user automatically. (If not, cast to text.) The schema-name is prepended automatically where necessary to be unambiguous in your session.
Get the actual "owner" (the role)
To get the role owning a specific sequence, as requested:
SELECT c.relname, u.usename
FROM pg_class c
JOIN pg_user u ON u.usesysid = c.relowner
WHERE c.oid = '"seqName"'::regclass; -- your sequence here

Answer 3

I was able to list the table and corresponding sequence for a particular column using the following SQL statement:
SELECT table_schema
, table_name
, column_name
, LTRIM(RTRIM(RTRIM(column_default, '::regclass)'),''''),'nextval(''') AS SEQUENCE_NAME
FROM information_schema.columns
WHERE column_default like '%nextval%';

Answer 4

SELECT c.relname,u.usename
FROM pg_class c, pg_user u
WHERE c.relowner = u.usesysid and c.relkind = 'S'
AND relnamespace IN (
SELECT oid
FROM pg_namespace
WHERE nspname NOT LIKE 'pg_%'
AND nspname != 'information_schema'
);

Answer 5

I use that query for get all queries.
Change CTE to filter the result
WITH table_with_sequence as (
SELECT
d.refobjid::regclass::text tablename,
c.relname::text sequencename,
np.nspname::text schemaname,
a.attname::text attname,
u.usename::text
FROM
pg_depend d
INNER JOIN pg_class c ON c.oid = d.objid
AND c.relkind = 'S'
INNER JOIN pg_namespace np ON np.oid = c.relnamespace
AND (np.nspname NOT LIKE 'pg_%'
AND np.nspname != 'information_schema')
INNER JOIN pg_user u ON u.usesysid = c.relowner
INNER JOIN pg_attribute a ON a.attrelid = d.refobjid
AND a.attnum = d.refobjsubid
)
SELECT
'ALTER SEQUENCE '|| QUOTE_LITERAL(QUOTE_IDENT(schemaname) || '.' || QUOTE_IDENT(sequencename)) ||' OWNED BY ' || tablename || '.' || QUOTE_IDENT(attname)
FROM table_with_sequence