Dear all, About the pg_buffercache view: I couldn't find the description for this view in the manual at http://www.postgresql.org/docs/8.2/interactive/catalogs.html However I found the readme file provided in the /contrib./pg_buffercache of the source code for version 8.2.3 Here it's written the following description: Column | references | Description ----------------+----------------------+------------------------------------ bufferid | | Id, 1..shared_buffers. relfilenode | pg_class.relfilenode | Refilenode of the relation. reltablespace | pg_tablespace.oid | Tablespace oid of the relation. reldatabase | pg_database.oid | Database for the relation. relblocknumber | | Offset of the page in the relation. isdirty | | Is the page dirty? I've 2 questions: 1) I was not able to find the field "oid" from pg_database view. Could you please tell me what is the actual name of the column for which reldatabase is reffering to? 2) In readme file is also written: "Unused buffers are shown with all fields null except buffered". A "used" buffer means that is used 100% or could it be filled only partially? Is there any way to know at a certain moment with precision how much shared memory expressed in Mb is used? With best regards, Sorin