Problem with Online-Backup

Hi all,

 

While there are inserts & updates happening into the database, is it possible to make the base backup without losing any of the updates in the database?

 

What does select pg_start_backup('label'); & pg_stop_backup(); do actually?

 

I am worried if the file system backup tool will not store the data files in the /pgsql/data/base which is still getting populated. Or does the segment file store that?

 

Will the Continuous backup or Hot backup (if any) solve the problem?

 

Thanks a lot in advance