I’ll demonstrate how to relocate a tablespace directory without the reconstruction of databases.

I have a tablespace tblspc located at /home/postgres/tblspc and want to relocate to /home/postgres/new_tblspc.

[1] Get Oid of the tablespace

testdb=# SELECT oid,spcname FROM pg_tablespace WHERE spcname = 'tblspc';
  oid  | spcname 
-------+----------
 24580 | tblspc
(1 row)

[2] Stop postgres

[postgres]$ pg_ctl -D $PGDATA stop

[3] Relocate the tablespace directory

[postgres]$ cp -r /home/postgres/tblspc /home/postgres/new_tblspc
[postgres]$ rm -rf /home/postgres/tblspc

[4] Change the link of tablespace to new directory

[postgres]$ cd $PGDATA/pg_tblspc
[postgres]$ rm 24580
[postgres]$ ln -s /home/postgres/new_tblspc 24580

[5] Start postgres

[postgres]$ pg_ctl -D $PGDATA start

Then, the tablespace’s directory has changed.

testdb=# SELECT pg_tablespace_location(24580);
  pg_tablespace_location
--------------------------
/home/postgres/new_tblspc
(1 row)

Reference

• The Internals of PostgreSQL