Relationship between xwikiattachment and pg_largeobject

Analyzing the size of the attached files (xwa_size field of the xwikiattachment table) in XWiki I get to 5.4GB, but in the pg_largeobject table is the size of 34GB. Can someone explain me, please, why is there such a difference in size?
How can I decrease the size of pg_largeobject? What else is stored in the pg_largeobject table?

Thanks in advance,
Julio Brum

I don’t know any pg_largeobject table, does not looks like an XWiki thing.

It’s a postgreSQL table, where I installed XWiki.

Then sorry I’m really not a Postgres expert. Maybe that’s where Postgres store the actual content of clob/blob fields of other tables.

Thanks Thomas!