pg_class就相当于oracle中dba_segments+dba_objects的并集。
查看某个文件或索引的relfileno
mydb2=# select relfilenode from pg_catalog.pg_class where relname='idx_my_tb2';
relfilenode
-------------
49307
[zjh@hs-10-20-30-193 data]$ find . -name "49307"
./base/49300/49307
查看某个relfileno对应的对象
例如，查询4930x这批的对象
mydb2=# select * from pg_catalog.pg_class where relfilenode=49302; oid | relname | relnamespace | reltype | reloftype | relowner | relam | relfilenode | relt ablespace | relpages | reltuples | relallvisible | reltoastrelid | relhasindex | relisshared | relpersistence | relkind | relnatts | relchecks | relhasrules | relhastriggers | relhassubc lass | relrowsecurity | relforcerowsecurity | relispopulated | relreplident | relispartition | relrewrite | relfrozenxid | relminmxid | relacl | reloptions | relpartbound -------+---------+--------------+---------+-----------+----------+-------+-------------+----- ----------+----------+-----------+---------------+---------------+-------------+------------- +----------------+---------+----------+-----------+-------------+----------------+----------- -----+----------------+---------------------+----------------+--------------+---------------- +------------+--------------+------------+--------+------------+-------------- 49302 | my_tb2 | 2200 | 49304 | 0 | 10 | 2 | 49302 | 0 | 0 | 0 | 0 | 0 | t | f | p | r | 2 | 0 | f | f | f | f | f | t | d | f | 0 | 587 | 1 | | | (1 row)
可知是对象my_tb2，类型定义在pg_type中，可以参见https://www.cnblogs.com/orangeform/archive/2012/05/25/2305415.html。