s/XIDs XIDs/XIDs/ in one place in maintenance.sgml.
Guillaume Lelarge
the <structfield>relfrozenxid</> column of a table's
<structname>pg_class</> row contains the freeze cutoff XID that was used
by the last whole-table <command>VACUUM</> for that table. All rows
- inserted by transactions with XIDs XIDs older than this cutoff XID are
+ inserted by transactions with XIDs older than this cutoff XID are
guaranteed to have been frozen. Similarly,
the <structfield>datfrozenxid</> column of a database's
<structname>pg_database</> row is a lower bound on the unfrozen XIDs