OID and filesystem issues

Hi All,

I have a couple of questions hopefully someone can help me with.

1) Does every relation exist in pg_class? Can we assume that if there is a file with OID which is not present in
pg_class,this file can be deleted? (we have a few such files, some of them take more than 2G of space in total) 

2) If we remove such file and run vaccum or pg_dump will we get into troubles ? Where does vaccum take information
aboutrelations from? pg_class or filesystem ? 

3) We have a relation which is unaccessible (permission denied), ls -l also prints this message so it's something with
filesystem.What would be the best procedure to solve this issue ? 

Thanks
Lee. *****************************************************
Lee Fedden
Software Developer
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