PostgreSQL 9.6 Temporary files

[Jimmy Augustine <jimmy.augustine@xxxxxxx>]

Dear Friends,

I am newbie to postgresql.

I have 162 GB on my database but when I check size of all tables, I approximately obtain 80 GB.

I also see that I have 68GB of temporary files however I only found 2.4MB at postgres/data/base/pgsql_tmp.

Could you tell me what are those temporary files and where are they at? Can I delete some of them?

All values come from pgAdmin 4 and checked by my own SQL queries(postgresql-9.6).
I already run vacuum full and there is few dead tuples.

Best regards,

Jimmy AUGUSTINE