Re: Finding referecing and referenced tables, adaptation from David Fetter's solution

On 30/07/11 10:45, bricklen wrote:
> [...]
> CREATE OR REPLACE VIEW table_dependencies AS (
> WITH RECURSIVE t AS (
> SELECT
> c.oid AS origin_id,
> c.oid::regclass::text AS origin_table,
> c.oid AS referencing_id,
> c.oid::regclass::text AS referencing_table,
> c2.oid AS referenced_id,
> c2.oid::regclass::text AS referenced_table,
> ARRAY[c.oid::regclass,c2.oid::regclass] AS chain
> FROM pg_catalog.pg_constraint AS co
> INNER JOIN pg_catalog.pg_class AS c
> ON c.oid = co.conrelid
> INNER JOIN pg_catalog.pg_class AS c2
> ON c2.oid = co.confrelid
> [...]
I am curious about the explicit use of INNER JOINs, I find them
cumbersome, so I rewrote the code to remove them, I know in some
situations that they can improve performance - but was this the case
here, or is there some other subtlety that I have missed?
[...]
SELECT
c1.oid::regclass::text AS origin_table,
c2.oid AS referenced_id,
c2.oid::regclass::text AS referenced_table,
ARRAY[c1.oid::regclass,c2.oid::regclass] AS chain
FROM
pg_catalog.pg_constraint AS co,
pg_catalog.pg_class AS c1,
pg_catalog.pg_class AS c2
WHERE
c1.oid = co.conrelid AND
c2.oid = co.confrelid
[...]

Cheers,
Gavin