Backing up postgresql databases

Hello,

How do people normally backup up postgresql databases? The obviously safe
solution is to shut down the database during backup, but is Postgresql
storage such that it's safe to backup a running DB? I.e., is the database
guaranteed to be in a consistent state after restoration?

I'm talking a standard backup procedure now; say a tar -czvf. So that
assuming certain procedures during storage, it should be possible to
guarantee this (although it wouldn't be easy). The questions is,
does Postgresql do that? I'm sceptical :)

Thanks!

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/ Peter Schuller, InfiDyne Technologies HB

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