Hi,

from: http://www.postgresql.org/docs/8.3/i...ions-info.html

'''
txid_current() bigint get current transaction ID
The internal transaction ID type (xid) is 32 bits wide and so it wraps around every 4 billion transactions. However,
these functions export a 64-bit format that is extended with an "epoch" counter so that it will not wrap around for the
life of an installation.
'''

What does 'epoch' counter mean? Seconds since 1970?

If you dump a table which stores values from txid_current() and restore them
in a new database, is possible that new ids will be duplicate?

Thomas