When indexes fail to build correctly they can be left in an invalid state. This is usually caused by lock contention or a long running transaction on the affected table when a build index command is run with the
An invalid index cannot be used by queries and should be dropped and rebuilt.
If an invalid index is detected, a recommendation will be created for the affected index. Take action to drop the index and rebuild it (with the
CONCURRENTLY option if necessary), or ignore the recommendation to remove it from your recommendation dashboard.