Re: Elementary dependency look-up

On Wed, 9 Sep 2009, decibel wrote:

> What might be more useful is a view that takes the guesswork out of using
> pg_depend. Namely, convert (ref)classid into a catalog table name (or better
> yet, what type of object it is), (ref)objid into an actual object name, and
> (ref)objsubid into a real name.

Here's V1 of a depend unraveler I needed recently and that's saved me a
bunch of time:

SELECT
c1.oid as relid,
n1.nspname || '.' || c1.relname as relation,
c1.relkind,
CASE
WHEN c1.relkind='r' THEN 'table'
WHEN c1.relkind='i' THEN 'index'
WHEN c1.relkind='S' THEN 'sequence'
WHEN c1.relkind='v' THEN 'view'
WHEN c1.relkind='c' THEN 'composite'
WHEN c1.relkind='t' THEN 'TOAST'
ELSE '?'
END as "kind",
c2.oid as relid,
n2.nspname || '.' || c2.relname as dependency,
c2.relkind,
CASE
WHEN c2.relkind='r' THEN 'table'
WHEN c2.relkind='i' THEN 'index'
WHEN c2.relkind='S' THEN 'sequence'
WHEN c2.relkind='v' THEN 'view'
WHEN c2.relkind='c' THEN 'composite'
WHEN c2.relkind='t' THEN 'TOAST'
ELSE '?'
END as "kind"
FROM
pg_depend d,
pg_class c1,
pg_namespace n1,
pg_class c2,
pg_namespace n2
WHERE
d.objid = c1.oid AND
c1.relnamespace = n1.oid AND
n1.nspname NOT IN('information_schema', 'pg_catalog') AND
n1.nspname !~ '^pg_toast' AND

d.refobjid = c2.oid AND
c2.relnamespace = n2.oid AND
n2.nspname NOT IN('information_schema', 'pg_catalog') AND
n2.nspname !~ '^pg_toast' AND

c1.oid != c2.oid

GROUP BY n1.nspname,c1.relname,c1.oid,c1.relkind,
n2.nspname,c2.relname,c2.oid,c2.relkind
ORDER BY n1.nspname,c1.relname;

I could throw this on the Wiki as a code snippet if anyone else wanted to
tinker with it.

--
* Greg Smith gsmith(at)gregsmith(dot)com http://www.gregsmith.com Baltimore, MD