Unknown database folders in base directory

Hi,

I was checking one disk space issue in PostgreSQL server and noticed that
there are some folders which are not mapping to databases. I am not able to
link those folders with any database oid. Can we safely delete those
folders after shutting down the postgres? It is recommended to delete any
files and directories in database directory but I need to clean

postgres=# select oid,datname from pg_database;

oid | datname

------------+----------------------

1 | template1

12998 | template0

13003 | postgres

1360816673 | demo1

876257363 | demo2

568075126 | db01

2888078676 | app05_06

2893858702 | app10

2858172588 | app03

2911598776 | demo_auto

2911908415 | production_auto

-bash-4.1$ pwd

/var/lib/pgsql/9.4/data/base

-bash-4.1$ ls -ltr

total 12716

drwx------ 2 postgres postgres 4096 Feb 19 2016 *12998*

drwx------ 2 postgres postgres 12288 Feb 28 21:00 *1*

*drwx------ 2 postgres postgres 163840 Mar 19 18:18 2567078690*

*drwx------ 2 postgres postgres 237568 Mar 19 19:10 2567168798*

*drwx------ 2 postgres postgres 151552 Mar 19 19:19 2567176994*

*drwx------ 2 postgres postgres 172032 Mar 19 19:34 2567193375*

drwx------ 2 postgres postgres 12288 Mar 19 19:34 *13003*

drwx------ 2 postgres postgres 110592 Apr 1 14:58 *568075126*

drwx------ 2 postgres postgres 73728 Apr 25 21:28 *876257363*

drwx------ 2 postgres postgres 4096 May 4 02:24 *1360816673*

drwx------ 2 postgres postgres 536576 Jun 7 02:28 *2888078676*

drwx------ 2 postgres postgres 81920 Jun 7 04:14 *2911598776*

drwx------ 2 postgres postgres 573440 Jun 7 07:10 *2858172588*

drwx------ 2 postgres postgres 258048 Jun 7 07:40 *2911908415*

drwx------ 2 postgres postgres 9859072 Jun 7 08:14 *pgsql_tmp*

drwx------ 2 postgres postgres 720896 Jun 7 08:35 *2893858702*

-bash-4.1$

-bash-4.1$ du -sh *

6.6M 1

6.6M 12998

126M 13003

6.7M 1360816673

*42G 2567078690*

*136G 2567168798*

*84G 2567176994*

*96G 2567193375*

82G 2858172588

83G 2888078676

83G 2893858702

12G 2911598776

276G 2911908415

59G 568075126

3.2G 876257363

19G pgsql_tmp

postgres=# select version();

version

---------------------------------------------------------------------------------------------------------------

PostgreSQL 9.4.5 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.4.7
20120313 (Red Hat 4.4.7-16), 64-bit

(1 row)

postgres=# \! cat /etc/issue

CentOS release 6.7 (Final)

Kernel \r on an \m

Cheers,

Adarsh Sharma