Some environments have many indexes configured though only a few are used for performance-sensitive traffic.
  1. To reduce server start up time, preload only 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. To apply the changes, restart the Directory Server.
    1. Run bin/stop-server.
    2. Run bin/start-server.