I’m using this SQL query to create an index:
$query = "CREATE INDEX id_index2
ON countries(geoname_id, name)";
How do I update the index when new entries are added?
Should I run a PHP script with the update query in CRON and run it every night?
Is this best practice for automated index updating?
Indexes are updated by MySQL automatically as you insert/update rows. (This may be a performance hitter for huge websites, but you probably aren’t running a huge one :).) You don’t need to do anything after the initial creation.