Finding the size of your biggest relations

Hi all.

i am running this query to get to 20 biggest tables but getting only
pg_temp** records like this without size:

"pg_toast_temp_39.pg_toast_1384618609";""
"pg_toast_temp_146.pg_toast_1384509547_index";""
"pg_temp_5.tt_photo";""
"pg_toast_temp_146.pg_toast_1384494807";""
"pg_temp_58.tt_category_action_brands_АкцияГУИД_idx";""
"pg_toast_temp_56.pg_toast_1384618787_index";""
"pg_toast_temp_47.pg_toast_1384618711";""
"pg_toast_temp_58.pg_toast_1384618621_index";""
"pg_toast_temp_5.pg_toast_1384618426_index";""
"pg_temp_32.tt1";""
"pg_temp_5.tt_accessory_kit_composition_НоменклатураГУИД_idx";""
"pg_toast_temp_112.pg_toast_1384472524";""
"pg_toast_temp_27.pg_toast_1384618423_index";""

How can i fix it? As i understand this is temp tables that was created
during run of some heavy queries that didn't fit in to work_mem and was
dumped on disk.
How i can remove it from stats, just restart postgre will help?
pgsql_tmp dir doesn't contain those files, so i can assume that they
already deleted from disk?

Thanks!