1. Some environments have many indexes configured, though only a few are used for performance-sensitive traffic. In this case, server start up time can be reduced by only preloading the necessary indexes into the database at startup.
    $ bin/dsconfig set-backend-prop --backend-name userRoot \ 
      --set prime-method:preload \ 
      --set prime-all-indexes:false \ 
      --set system-index-to-prime:dn2id \
      --set system-index-to-prime:id2entry
    $ bin/dsconfig set-local-db-index-prop --backend-name userRoot \
      --index-name mail \
      --set prime-index:true
    $ bin/dsconfig set-local-db-index-prop --backend-name userRoot \
      --index-name uid \
      --set prime-index:true
    $ bin/dsconfig set-local-db-index-prop --backend-name userRoot \
      --index-name entryUUID \
      --set prime-index:true
  2. Restart the Directory Server to apply the changes using bin/stop-server and then, bin/start-server.