(PECL solr >= 0.9.2)
SolrClient::optimize — Defragments the index
Defragments the index for faster search performance.
Optimizes down to at most this number of segments. Since Solr 1.3
Block until index changes are flushed to disk.
Block until a new searcher is opened and registered as the main query searcher, making the changes visible.
Returns a SolrUpdateResponse on success or throws a SolrClientException on failure.