Solr did not used to be at all like a database. It was designed to excel at searching, leaving data storage and rapid in-place updates to regular databases. However, with new features in Version 4, such as soft commits and other Near Real Time optimizations, Solr can substitute a database in previously impossible scenarios. Partial record (Atomic) update is also one of these features. It allows sending only changed document fields to Solr as part of the add/update command and having them merged with already known values for other fields of the same document.
commitdirectory to the
updatedirectory, delete the
datadirectory, and add the core reference to