RE: bug with dropping tables and transactions.

> -----Original Message-----
> From: Alfred Perlstein
> 
> There seems to a race condition somewhere where that if you're
> running let's say pg_dumpall and happen to drop a table mid-dump
> pg_dumpall will die because it looses the table.
> 
> Would it make sense to use a transaction system so that when a table
> is renamed/dropped it doesn't actually go away until all transactions
> that started before the drop take place?
> 
> one could do probably implement this using refcounts and translating
> dropped tables into temporary mangled names.
> 

Your proposal seems to be an extension of how to commit/rollback
DDL (drop/alter/rename etc ..) commands properly. There has been
a long discussion about it but unfortunately we have no consensus
for it AFAIK.

There may be another way.
pg_dump(all) may be able to acquire a e.g share lock for pg_class
to prevent drop/rename/.. operations of other backends. Of cource
DDL(drop/rename/..) commands should acquire a row exclusive
lock on pg_class.

Regards.

Hiroshi Inoue