The Lucene database is constantly updated with content changes. However, it’s sometimes necessary to create with a new index. This might be because data was modified directly on the database, or and index corruption is suspected. If a full reindex is selected, the operation will happen in the background, and dotCMS will continue to use the old index until the new index is complete.
Content belonging to a single content type can also be reindexed, In this case, the contents belonging to the selected content type will be reindexed in the current index.
For more information on how indices are created and managed in dotCMS using ElasticSearch click here.