Hannu Krosing <hannu@tm.ee> writes:
> 1) record the lowest uncommitted transaction number (LUTN) , this may
> have problems with wraparound, but I guess they are solvable. Disllow
> VACUUM. Do a CHECKPOINT ('alter database begin backup')
> 3) make a file-level (.tar) backup of data directory.
> 4) Allow VACUUM. ('alter database end backup')
Transactions don't necessarily commit in sequence number order, so the
concept of LUTN seems meaningless.
Why is it necessary (or even good) to disallow VACUUM? I really dislike
a design that allows the DBA to cripple the database by forgetting the
last step in a (long) process.
regards, tom lane