access during the VACUUM. A new VACUUM FULL command does old-style
vacuum by locking the table and shrinking the on-disk copy of the table.
+ Transactions - There is no longer a problem with installations
+that exceed four billion transactions.
+
+ OID's - OID's are now optional. Users can now create tables
+without OID's for cases where OID usage is excessive.
+
+ Optimizer - The system now computes histogram column statistics
+during ANALYZE, allowing much better optimizer choices.
+
Security - A new MD5 encryption option allows much more secure
storage and transfer of passwords. A new unix-domain socket
authentication option is available on Linux and *BSD systems.