My pg_largeobject table filenode is 16404:
(select relfilenode from pg_class where relname='pg_largeobject')
Pages (record) count in table pg_largeobject: 73574 -> 144 MB (73574 * 2Kb)
(select count(loid) from pg_largeobject)
Relation pages count (in table pg_class) for table pg_largeobject:
23713 -> 185 MB (23713 * 8 Kb)
(select relpages from pg_class where relname='pg_largeobject')
Total:
144 MB - data in table pg_largeobject
186 MB - size on disk for table pg_largeobject
Question:
185 MB - 144MB = 41 MB - what is in this memory on disk?