operating system's collation library for character set ordering.
This controls the ordering of keys stored in indexes. For this reason,
a cluster cannot switch to an incompatible collation library version,
- either through snapshot restore, binary streaming replication, or
- <application>pg_upgrade</> run.
+ either through snapshot restore, binary streaming replication, a
+ different operating system, or an operating system upgrade.
</para>
<sect2 id="creating-cluster-mount-points">