PostgreSQL: toast table

TOAST is a special class of tables in PostgreSQL that store "big" data. Big data refers to rows whose size exceeds the size of one data sheet (8k), the row is split into granules ~2000 bytes in size and placed in the specified table.

select relname,
oid,
pg_size_pretty(pg_table_size(oid)) "size"
from pg_class
where oid =
(select reltoastrelid
from pg_class
where relname= $$TABLENAME
and relnamespace =
(select oid
from pg_catalog.pg_namespace n
where nspname = $$SCHEMANAME)
)